SQLite

  $(TOP)/src/test6.c \
  $(TOP)/src/test7.c \
  $(TOP)/src/test8.c \
  $(TOP)/src/test9.c \
  $(TOP)/src/test_autoext.c \
  $(TOP)/src/test_async.c \
  $(TOP)/src/test_backup.c \
  $(TOP)/src/test_blob.c \
  $(TOP)/src/test_btree.c \
  $(TOP)/src/test_config.c \
  $(TOP)/src/test_demovfs.c \
  $(TOP)/src/test_devsym.c \
  $(TOP)/src/test_fs.c \
  $(TOP)/src/test_func.c \
  $(TOP)/src/test_hexio.c \

  $(TOP)\src\test6.c \
  $(TOP)\src\test7.c \
  $(TOP)\src\test8.c \
  $(TOP)\src\test9.c \
  $(TOP)\src\test_autoext.c \
  $(TOP)\src\test_async.c \
  $(TOP)\src\test_backup.c \
  $(TOP)\src\test_blob.c \
  $(TOP)\src\test_btree.c \
  $(TOP)\src\test_config.c \
  $(TOP)\src\test_demovfs.c \
  $(TOP)\src\test_devsym.c \
  $(TOP)\src\test_fs.c \
  $(TOP)\src\test_func.c \
  $(TOP)\src\test_hexio.c \

** of m for the first i bytes of a word.
**
** Return true if the m-value for z is 1 or more.  In other words,
** return true if z contains at least one vowel that is followed
** by a consonant.
**
** In this routine z[] is in reverse order.  So we are really looking
** for an instance of of a consonant followed by a vowel.
** for an instance of a consonant followed by a vowel.
*/
static int m_gt_0(const char *z){
  while( isVowel(z) ){ z++; }
  if( *z==0 ) return 0;
  while( isConsonant(z) ){ z++; }
  return *z!=0;
}

SQLITE_EXTENSION_INIT1
#include <string.h>

/*
** Structure used to accumulate the output
*/
struct EvalResult {
  char *z;            /* Accumulated output */
  const char *zSep;   /* Separator */
  int szSep;          /* Size of the separator string */
  int nAlloc;         /* Number of bytes allocated for z[] */
  int nUsed;          /* Number of bytes of z[] actually used */
  char *z;               /* Accumulated output */
  const char *zSep;      /* Separator */
  int szSep;             /* Size of the separator string */
  sqlite3_int64 nAlloc;  /* Number of bytes allocated for z[] */
  sqlite3_int64 nUsed;   /* Number of bytes of z[] actually used */
};

/*
** Callback from sqlite_exec() for the eval() function.
*/
static int callback(void *pCtx, int argc, char **argv, char **colnames){
  struct EvalResult *p = (struct EvalResult*)pCtx;
  int i; 
  for(i=0; i<argc; i++){
    const char *z = argv[i] ? argv[i] : "";
    size_t sz = strlen(z);
    if( sz+p->nUsed+p->szSep+1 > p->nAlloc ){
    if( (sqlite3_int64)sz+p->nUsed+p->szSep+1 > p->nAlloc ){
      char *zNew;
      p->nAlloc = p->nAlloc*2 + sz + p->szSep + 1;
      /* Using sqlite3_realloc64() would be better, but it is a recent
      ** addition and will cause a segfault if loaded by an older version
      ** of SQLite.  */
      zNew = sqlite3_realloc(p->z, p->nAlloc);
      zNew = p->nAlloc<=0x7fffffff ? sqlite3_realloc(p->z, (int)p->nAlloc) : 0;
      if( zNew==0 ){
        sqlite3_free(p->z);
        memset(p, 0, sizeof(*p));
        return 1;
      }
      p->z = zNew;
    }

  if( rc!=SQLITE_OK ){
    sqlite3_result_error(context, zErr, -1);
    sqlite3_free(zErr);
  }else if( x.zSep==0 ){
    sqlite3_result_error_nomem(context);
    sqlite3_free(x.z);
  }else{
    sqlite3_result_text(context, x.z, x.nUsed, sqlite3_free);
    sqlite3_result_text(context, x.z, (int)x.nUsed, sqlite3_free);
  }
}


#ifdef _WIN32
__declspec(dllexport)
#endif

  int i;
  tRowcnt v;

#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  if( z==0 ) z = "";
#else
  assert( z!=0 );
  pIndex->bUnordered = 0;
  pIndex->noSkipScan = 0;
#endif
  for(i=0; *z && i<nOut; i++){
    v = 0;
    while( (c=z[0])>='0' && c<='9' ){
      v = v*10 + c - '0';
      z++;
    }
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    if( aOut ) aOut[i] = v;
    if( aLog ) aLog[i] = sqlite3LogEst(v);
#else
    assert( aOut==0 );
    UNUSED_PARAMETER(aOut);
    assert( aLog!=0 );
    aLog[i] = sqlite3LogEst(v);
#endif
    if( *z==' ' ) z++;
  }
#ifndef SQLITE_ENABLE_STAT3_OR_STAT4
  assert( pIndex!=0 );
  assert( pIndex!=0 ); {
#else
  if( pIndex )
  if( pIndex ){
#endif
    pIndex->bUnordered = 0;
    pIndex->noSkipScan = 0;
  while( z[0] ){
    if( sqlite3_strglob("unordered*", z)==0 ){
      pIndex->bUnordered = 1;
    }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){
      pIndex->szIdxRow = sqlite3LogEst(sqlite3Atoi(z+3));
    }else if( sqlite3_strglob("noskipscan*", z)==0 ){
      pIndex->noSkipScan = 1;
    }
    while( z[0] ){
      if( sqlite3_strglob("unordered*", z)==0 ){
        pIndex->bUnordered = 1;
      }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){
        pIndex->szIdxRow = sqlite3LogEst(sqlite3Atoi(z+3));
      }else if( sqlite3_strglob("noskipscan*", z)==0 ){
        pIndex->noSkipScan = 1;
      }
#ifdef SQLITE_ENABLE_COSTMULT
    else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){
      pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9));
    }
      else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){
        pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9));
      }
#endif
    while( z[0]!=0 && z[0]!=' ' ) z++;
    while( z[0]==' ' ) z++;
      while( z[0]!=0 && z[0]!=' ' ) z++;
      while( z[0]==' ' ) z++;
    }
  }
}

/*
** This callback is invoked once for each index when reading the
** sqlite_stat1 table.  
**

      int i;                    /* Used to iterate through samples */
      tRowcnt sumEq = 0;        /* Sum of the nEq values */
      tRowcnt avgEq = 0;
      tRowcnt nRow;             /* Number of rows in index */
      i64 nSum100 = 0;          /* Number of terms contributing to sumEq */
      i64 nDist100;             /* Number of distinct values in index */

      if( pIdx->aiRowEst==0 || pIdx->aiRowEst[iCol+1]==0 ){
      if( !pIdx->aiRowEst || iCol>=pIdx->nKeyCol || pIdx->aiRowEst[iCol+1]==0 ){
        nRow = pFinal->anLt[iCol];
        nDist100 = (i64)100 * pFinal->anDLt[iCol];
        nSample--;
      }else{
        nRow = pIdx->aiRowEst[0];
        nDist100 = ((i64)100 * pIdx->aiRowEst[0]) / pIdx->aiRowEst[iCol+1];
      }

  /* The request could not be fulfilled using a freelist slot.  Check
  ** to see if defragmentation is necessary.
  */
  testcase( gap+2+nByte==top );
  if( gap+2+nByte>top ){
 defragment_page:
    testcase( pPage->nCell==0 );
    assert( pPage->nCell>0 || CORRUPT_DB );
    rc = defragmentPage(pPage);
    if( rc ) return rc;
    top = get2byteNotZero(&data[hdr+5]);
    assert( gap+nByte<=top );
  }

    assert( pFree>aData && (pFree - aData)<65536 );
    freeSpace(pPg, (u16)(pFree - aData), szFree);
  }
  return nRet;
}

/*
** apCell[] and szCell[] contains pointers to and sizes of all cells in the
** pages being balanced.  The current page, pPg, has pPg->nCell cells starting
** with apCell[iOld].  After balancing, this page should hold nNew cells
** starting at apCell[iNew].
**
** This routine makes the necessary adjustments to pPg so that it contains
** the correct cells after being balanced.
**
** The pPg->nFree field is invalid when this function returns. It is the
** responsibility of the caller to set it correctly.
*/
static void editPage(
  MemPage *pPg,                   /* Edit this page */
  int iOld,                       /* Index of first cell currently on page */
  int iNew,                       /* Index of new first cell on page */

  }
  if( iNewEnd < iOldEnd ){
    nCell -= pageFreeArray(
        pPg, iOldEnd-iNewEnd, &apCell[iNewEnd], &szCell[iNewEnd]
    );
  }

  pData = &aData[get2byte(&aData[hdr+5])];
  pData = &aData[get2byteNotZero(&aData[hdr+5])];
  if( pData<pBegin ) goto editpage_fail;

  /* Add cells to the start of the page */
  if( iNew<iOld ){
    int nAdd = iOld-iNew;
    int nAdd = MIN(nNew,iOld-iNew);
    assert( (iOld-iNew)<nNew || nCell==0 || CORRUPT_DB );
    pCellptr = pPg->aCellIdx;
    memmove(&pCellptr[nAdd*2], pCellptr, nCell*2);
    if( pageInsertArray(
          pPg, pBegin, &pData, pCellptr,
          nAdd, &apCell[iNew], &szCell[iNew]
    ) ) goto editpage_fail;
    nCell += nAdd;

  Pgno pgnoNew;                        /* Page number of pNew */

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( sqlite3PagerIswriteable(pParent->pDbPage) );
  assert( pPage->nOverflow==1 );

  /* This error condition is now caught prior to reaching this function */
  if( pPage->nCell==0 ) return SQLITE_CORRUPT_BKPT;
  if( NEVER(pPage->nCell==0) ) return SQLITE_CORRUPT_BKPT;

  /* Allocate a new page. This page will become the right-sibling of 
  ** pPage. Make the parent page writable, so that the new divider cell
  ** may be inserted. If both these operations are successful, proceed.
  */
  rc = allocateBtreePage(pBt, &pNew, &pgnoNew, 0, 0);

        assert( pOld->hdrOffset==0 );
        /* The right pointer of the child page pOld becomes the left
        ** pointer of the divider cell */
        memcpy(apCell[nCell], &pOld->aData[8], 4);
      }else{
        assert( leafCorrection==4 );
        if( szCell[nCell]<4 ){
          /* Do not allow any cells smaller than 4 bytes. */
          /* Do not allow any cells smaller than 4 bytes. If a smaller cell
          ** does exist, pad it with 0x00 bytes. */
          assert( szCell[nCell]==3 );
          assert( apCell[nCell]==&pTemp[iSpace1-3] );
          pTemp[iSpace1++] = 0x00;
          szCell[nCell] = 4;
        }
      }
      nCell++;
    }
  }

      /* Cell pCell is destined for new sibling page pNew. Originally, it
      ** was either part of sibling page iOld (possibly an overflow cell), 
      ** or else the divider cell to the left of sibling page iOld. So,
      ** if sibling page iOld had the same page number as pNew, and if
      ** pCell really was a part of sibling page iOld (not a divider or
      ** overflow cell), we can skip updating the pointer map entries.  */
      if( iOld>=nNew
       || pNew->pgno!=aPgno[iOld]
       || pCell<aOld
      if( pNew->pgno!=aPgno[iOld] || pCell<aOld || pCell>=&aOld[usableSize] ){
       || pCell>=&aOld[usableSize]
      ){
        if( !leafCorrection ){
          ptrmapPut(pBt, get4byte(pCell), PTRMAP_BTREE, pNew->pgno, &rc);
        }
        if( szCell[i]>pNew->minLocal ){
          ptrmapPutOvflPtr(pNew, pCell, &rc);
        }
      }

    case TK_INTEGER:
    case TK_STRING:
    case TK_FLOAT:
    case TK_BLOB:
      return 0;
    case TK_COLUMN:
      assert( p->pTab!=0 );
      return ExprHasProperty(p, EP_CanBeNull) ||
      return p->iColumn>=0 && p->pTab->aCol[p->iColumn].notNull==0;
             (p->iColumn>=0 && p->pTab->aCol[p->iColumn].notNull==0);
    default:
      return 1;
  }
}

/*
** Return TRUE if the given expression is a constant which would be

  /* Free any outstanding Savepoint structures. */
  sqlite3CloseSavepoints(db);

  /* Close all database connections */
  for(j=0; j<db->nDb; j++){
    struct Db *pDb = &db->aDb[j];
    if( pDb->pBt ){
      if( pDb->pSchema ){
        /* Must clear the KeyInfo cache.  See ticket [e4a18565a36884b00edf] */
        for(i=sqliteHashFirst(&pDb->pSchema->idxHash); i; i=sqliteHashNext(i)){
          Index *pIdx = sqliteHashData(i);
          sqlite3KeyInfoUnref(pIdx->pKeyInfo);
          pIdx->pKeyInfo = 0;
        }
      }
      sqlite3BtreeClose(pDb->pBt);
      pDb->pBt = 0;
      if( j!=1 ){
        pDb->pSchema = 0;
      }
    }
  }

  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif

  /* Initialize the output variables to -1 in case an error occurs. */
  if( pnLog ) *pnLog = -1;
  if( pnCkpt ) *pnCkpt = -1;

  assert( SQLITE_CHECKPOINT_FULL>SQLITE_CHECKPOINT_PASSIVE );
  assert( SQLITE_CHECKPOINT_FULL<SQLITE_CHECKPOINT_RESTART );
  assert( SQLITE_CHECKPOINT_PASSIVE+2==SQLITE_CHECKPOINT_RESTART );
  if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_RESTART ){
  assert( SQLITE_CHECKPOINT_PASSIVE==0 );
  assert( SQLITE_CHECKPOINT_FULL==1 );
  assert( SQLITE_CHECKPOINT_RESTART==2 );
  assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
  if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
    /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
    ** mode: */
    return SQLITE_MISUSE;
  }

  sqlite3_mutex_enter(db->mutex);
  if( zDb && zDb[0] ){
    iDb = sqlite3FindDbName(db, zDb);
  }

/*
** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
** to contains a zero-length string, all attached databases are 
** checkpointed.
*/
int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
  /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
  ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
  return sqlite3_wal_checkpoint_v2(db, zDb, SQLITE_CHECKPOINT_PASSIVE, 0, 0);
  return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
}

#ifndef SQLITE_OMIT_WAL
/*
** Run a checkpoint on database iDb. This is a no-op if database iDb is
** not currently open in WAL mode.
**

**
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
*/
int sqlite3PagerCheckpoint(Pager *pPager, int eMode, int *pnLog, int *pnCkpt){
  int rc = SQLITE_OK;
  if( pPager->pWal && PagerOtaMode(pPager)==0 ){
    rc = sqlite3WalCheckpoint(pPager->pWal, eMode,
        (eMode==SQLITE_CHECKPOINT_PASSIVE ? 0 : pPager->xBusyHandler),
        pPager->xBusyHandler, pPager->pBusyHandlerArg,
        pPager->pBusyHandlerArg,
        pPager->ckptSyncFlags, pPager->pageSize, (u8 *)pPager->pTmpSpace,
        pnLog, pnCkpt
    );
  }
  return rc;
}

    }
  }
  break;
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

#ifndef SQLITE_OMIT_WAL
  /*
  **   PRAGMA [database.]wal_checkpoint = passive|full|restart
  **   PRAGMA [database.]wal_checkpoint = passive|full|restart|truncate
  **
  ** Checkpoint the database.
  */
  case PragTyp_WAL_CHECKPOINT: {
    int iBt = (pId2->z?iDb:SQLITE_MAX_ATTACHED);
    int eMode = SQLITE_CHECKPOINT_PASSIVE;
    if( zRight ){
      if( sqlite3StrICmp(zRight, "full")==0 ){
        eMode = SQLITE_CHECKPOINT_FULL;
      }else if( sqlite3StrICmp(zRight, "restart")==0 ){
        eMode = SQLITE_CHECKPOINT_RESTART;
      }else if( sqlite3StrICmp(zRight, "truncate")==0 ){
        eMode = SQLITE_CHECKPOINT_TRUNCATE;
      }
    }
    sqlite3VdbeSetNumCols(v, 3);
    pParse->nMem = 3;
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "busy", SQLITE_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "log", SQLITE_STATIC);
    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "checkpointed", SQLITE_STATIC);

            break;
          }
        }
      }
      if( pMatch ){
        pExpr->iTable = pMatch->iCursor;
        pExpr->pTab = pMatch->pTab;
        assert( (pMatch->jointype & JT_RIGHT)==0 ); /* RIGHT JOIN not (yet) supported */
        if( (pMatch->jointype & JT_LEFT)!=0 ){
          ExprSetProperty(pExpr, EP_CanBeNull);
        }
        pSchema = pExpr->pTab->pSchema;
      }
    } /* if( pSrcList ) */

#ifndef SQLITE_OMIT_TRIGGER
    /* If we have not already resolved the name, then maybe 
    ** it is a new.* or old.* trigger argument reference

  ** if the select-list is the same as the ORDER BY list, then this query
  ** can be rewritten as a GROUP BY. In other words, this:
  **
  **     SELECT DISTINCT xyz FROM ... ORDER BY xyz
  **
  ** is transformed to:
  **
  **     SELECT xyz FROM ... GROUP BY xyz
  **     SELECT xyz FROM ... GROUP BY xyz ORDER BY xyz
  **
  ** The second form is preferred as a single index (or temp-table) may be 
  ** used for both the ORDER BY and DISTINCT processing. As originally 
  ** written the query must use a temp-table for at least one of the ORDER 
  ** BY and DISTINCT, and an index or separate temp-table for the other.
  */
  if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct 
   && sqlite3ExprListCompare(sSort.pOrderBy, p->pEList, -1)==0
  ){
    p->selFlags &= ~SF_Distinct;
    p->pGroupBy = sqlite3ExprListDup(db, p->pEList, 0);
    pGroupBy = p->pGroupBy;
    sSort.pOrderBy = 0;
    /* Notice that even thought SF_Distinct has been cleared from p->selFlags,
    ** the sDistinct.isTnct is still set.  Hence, isTnct represents the
    ** original setting of the SF_Distinct flag, not the current setting */
    assert( sDistinct.isTnct );
  }

  /* If there is an ORDER BY clause, then this sorting

  return argv[i];
}

int main(int argc, char **argv){
  char *zErrMsg = 0;
  ShellState data;
  const char *zInitFile = 0;
  char *zFirstCmd = 0;
  int i;
  int rc = 0;
  int warnInmemoryDb = 0;
  int readStdin = 1;
  int nCmd = 0;
  char **azCmd = 0;

#if USE_SYSTEM_SQLITE+0!=1
  if( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)!=0 ){
    fprintf(stderr, "SQLite header and source version mismatch\n%s\n%s\n",
            sqlite3_sourceid(), SQLITE_SOURCE_ID);
    exit(1);
  }
#endif
  Argv0 = argv[0];
  main_init(&data);
  stdin_is_interactive = isatty(0);

  /* Make sure we have a valid signal handler early, before anything
  ** else is done.
  */
#ifdef SIGINT
  signal(SIGINT, interrupt_handler);
#endif

#ifdef SQLITE_SHELL_DBNAME_PROC
  {
    /* If the SQLITE_SHELL_DBNAME_PROC macro is defined, then it is the name
    ** of a C-function that will provide the name of the database file.  Use
    ** this compile-time option to embed this shell program in larger
    ** applications. */
    extern void SQLITE_SHELL_DBNAME_PROC(const char**);
    SQLITE_SHELL_DBNAME_PROC(&data.zDbFilename);
    warnInmemoryDb = 0;
  }
#endif

  /* Do an initial pass through the command-line argument to locate
  ** the name of the database file, the name of the initialization file,
  ** the size of the alternative malloc heap,
  ** and the first command to execute.
  */
  for(i=1; i<argc; i++){
    char *z;
    z = argv[i];
    if( z[0]!='-' ){
      if( data.zDbFilename==0 ){
        data.zDbFilename = z;
      }else{
        /* Excesss arguments are interpreted as SQL (or dot-commands) and
        ** mean that nothing is read from stdin */
        continue;
      }
        readStdin = 0;
        nCmd++;
        azCmd = realloc(azCmd, sizeof(azCmd[0])*nCmd);
        if( azCmd==0 ){
          fprintf(stderr, "out of memory\n");
          exit(1);
        }
      if( zFirstCmd==0 ){
        zFirstCmd = z;
        azCmd[nCmd-1] = z;
        continue;
      }
      fprintf(stderr,"%s: Error: too many options: \"%s\"\n", Argv0, argv[i]);
      fprintf(stderr,"Use -help for a list of options.\n");
      return 1;
    }
    if( z[1]=='-' ) z++;
    if( strcmp(z,"-separator")==0
     || strcmp(z,"-nullvalue")==0
     || strcmp(z,"-newline")==0
     || strcmp(z,"-cmd")==0
    ){

#ifndef SQLITE_OMIT_MEMORYDB
    data.zDbFilename = ":memory:";
    warnInmemoryDb = argc==1;
#else
    fprintf(stderr,"%s: Error: no database filename specified\n", Argv0);
    return 1;
#endif
#ifdef SQLITE_SHELL_DBNAME_PROC
    { extern void SQLITE_SHELL_DBNAME_PROC(const char**);
      SQLITE_SHELL_DBNAME_PROC(&data.zDbFilename);
      warnInmemoryDb = 0; }
#endif
  }
  data.out = stdout;

  /* Go ahead and open the database file if it already exists.  If the
  ** file does not exist, delay opening it.  This prevents empty database
  ** files from being created if a user mistypes the database name argument
  ** to the sqlite command-line tool.

#ifdef SQLITE_ENABLE_MULTIPLEX
    }else if( strcmp(z,"-multiplex")==0 ){
      i++;
#endif
    }else if( strcmp(z,"-help")==0 ){
      usage(1);
    }else if( strcmp(z,"-cmd")==0 ){
      /* Run commands that follow -cmd first and separately from commands
      ** that simply appear on the command-line.  This seems goofy.  It would
      ** be better if all commands ran in the order that they appear.  But
      ** we retain the goofy behavior for historical compatibility. */
      if( i==argc-1 ) break;
      z = cmdline_option_value(argc,argv,++i);
      if( z[0]=='.' ){
        rc = do_meta_command(z, &data);
        if( rc && bail_on_error ) return rc==2 ? 0 : rc;
      }else{
        open_db(&data, 0);

    }else{
      fprintf(stderr,"%s: Error: unknown option: %s\n", Argv0, z);
      fprintf(stderr,"Use -help for a list of options.\n");
      return 1;
    }
  }

  if( zFirstCmd ){
    /* Run just the command that follows the database name
  if( !readStdin ){
    /* Run all arguments that do not begin with '-' as if they were separate
    ** command-line inputs, except for the argToSkip argument which contains
    ** the database filename.
    */
    for(i=0; i<nCmd; i++){
    if( zFirstCmd[0]=='.' ){
      rc = do_meta_command(zFirstCmd, &data);
      if( rc==2 ) rc = 0;
    }else{
      open_db(&data, 0);
      rc = shell_exec(data.db, zFirstCmd, shell_callback, &data, &zErrMsg);
      if( zErrMsg!=0 ){
        fprintf(stderr,"Error: %s\n", zErrMsg);
        return rc!=0 ? rc : 1;
      }else if( rc!=0 ){
        fprintf(stderr,"Error: unable to process SQL \"%s\"\n", zFirstCmd);
        return rc;
      }
    }
      if( azCmd[i][0]=='.' ){
        rc = do_meta_command(azCmd[i], &data);
        if( rc ) return rc==2 ? 0 : rc;
      }else{
        open_db(&data, 0);
        rc = shell_exec(data.db, azCmd[i], shell_callback, &data, &zErrMsg);
        if( zErrMsg!=0 ){
          fprintf(stderr,"Error: %s\n", zErrMsg);
          return rc!=0 ? rc : 1;
        }else if( rc!=0 ){
          fprintf(stderr,"Error: unable to process SQL: %s\n", azCmd[i]);
          return rc;
        }
      }
    }
    free(azCmd);
  }else{
    /* Run commands received from standard input
    */
    if( stdin_is_interactive ){
      char *zHome;
      char *zHistory = 0;
      int nHistory;

** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
** </ul>
**
** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
** was given no the corresponding lock.  
** was given on the corresponding lock.  
**
** The xShmLock method can transition between unlocked and SHARED or
** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
** and EXCLUSIVE.
*/
#define SQLITE_SHM_UNLOCK       1
#define SQLITE_SHM_LOCK         2

** This option can be used to overload the default memory allocation
** routines with a wrapper that simulations memory allocation failure or
** tracks memory usage, for example. </dd>
**
** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
** interpreted as a boolean, which enables or disables the collection of
** memory allocation statistics. ^(When memory allocation statistics are disabled, the 
** following SQLite interfaces become non-operational:
** memory allocation statistics. ^(When memory allocation statistics are
** disabled, the following SQLite interfaces become non-operational:
**   <ul>
**   <li> [sqlite3_memory_used()]
**   <li> [sqlite3_memory_highwater()]
**   <li> [sqlite3_soft_heap_limit64()]
**   <li> [sqlite3_status()]
**   </ul>)^
** ^Memory allocation statistics are enabled by default unless SQLite is

** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer
** that SQLite can use for the database page cache with the default page
** cache implementation.  
** This configuration should not be used if an application-define page
** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]
** configuration option.
** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned
** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
** 8-byte aligned
** memory, the size of each page buffer (sz), and the number of pages (N).
** The sz argument should be the size of the largest database page
** (a power of two between 512 and 32768) plus some extra bytes for each
** page header.  ^The number of extra bytes needed by the page header
** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option 
** to [sqlite3_config()].
** ^It is harmless, apart from the wasted memory,
** for the sz parameter to be larger than necessary.  The first
** argument should pointer to an 8-byte aligned block of memory that
** is at least sz*N bytes of memory, otherwise subsequent behavior is
** undefined.
** ^SQLite will use the memory provided by the first argument to satisfy its
** memory needs for the first N pages that it adds to cache.  ^If additional
** page cache memory is needed beyond what is provided by this option, then
** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd>
**
** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 
** that SQLite will use for all of its dynamic memory allocation needs
** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and
** [SQLITE_CONFIG_PAGECACHE].
** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
** [SQLITE_ERROR] if invoked otherwise.
** ^There are three arguments to SQLITE_CONFIG_HEAP:
** An 8-byte aligned pointer to the memory,
** the number of bytes in the memory buffer, and the minimum allocation size.
** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
** to using its default memory allocator (the system malloc() implementation),
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
** memory pointer is not NULL then the alternative memory
** allocator is engaged to handle all of SQLites memory allocation needs.
** The first pointer (the memory pointer) must be aligned to an 8-byte
** boundary or subsequent behavior of SQLite will be undefined.
** The minimum allocation size is capped at 2**12. Reasonable values
** for the minimum allocation size are 2**5 through 2**8.</dd>
**
** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
** pointer to an instance of the [sqlite3_mutex_methods] structure.
** The argument specifies alternative low-level mutex routines to be used in place
** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
** content of the [sqlite3_mutex_methods] structure before the call to
** The argument specifies alternative low-level mutex routines to be used
** in place the mutex routines built into SQLite.)^  ^SQLite makes a copy of
** the content of the [sqlite3_mutex_methods] structure before the call to
** [sqlite3_config()] returns. ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** the entire mutexing subsystem is omitted from the build and hence calls to
** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
** return [SQLITE_ERROR].</dd>
**
** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>

** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 
** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies
** the interface to a custom page cache implementation.)^
** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
**
** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of the current
** page cache implementation into that object.)^ </dd>
** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of
** the current page cache implementation into that object.)^ </dd>
**
** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
** global [error log].
** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
** function with a call signature of void(*)(void*,int,const char*), 
** and a pointer to void. ^If the function pointer is not NULL, it is

** supplied by the application must not invoke any SQLite interface.
** In a multi-threaded application, the application-defined logger
** function must be threadsafe. </dd>
**
** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
** If non-zero, then URI handling is globally enabled. If the parameter is zero,
** then URI handling is globally disabled.)^ ^If URI handling is globally enabled,
** all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
** then URI handling is globally disabled.)^ ^If URI handling is globally
** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
** [sqlite3_open16()] or
** specified as part of [ATTACH] commands are interpreted as URIs, regardless
** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
** connection is opened. ^If it is globally disabled, filenames are
** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
** database connection is opened. ^(By default, URI handling is globally
** disabled. The default value may be changed by compiling with the
** [SQLITE_USE_URI] symbol defined.)^

** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
** ^If either argument to this option is negative, then that argument is
** changed to its compile-time default.
**
** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro defined.
** ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
** that specifies the maximum size of the created heap.
** </dl>
**
** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
** is a pointer to an integer and writes into that integer the number of extra
** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. The amount of
** extra space required can change depending on the compiler,
** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
** The amount of extra space required can change depending on the compiler,
** target platform, and SQLite version.
** </dl>
*/
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */

** UTF-16 string in native byte order.
*/
int sqlite3_complete(const char *sql);
int sqlite3_complete16(const void *sql);

/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
** KEYWORDS: {busy-handler callback} {busy handler}
**
** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
** that might be invoked with argument P whenever
** an attempt is made to access a database table associated with
** [database connection] D when another thread
** or process has the table locked.
** The sqlite3_busy_handler() interface is used to implement
** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
**
** ^If the busy callback is NULL, then [SQLITE_BUSY]
** is returned immediately upon encountering the lock.  ^If the busy callback
** is not NULL, then the callback might be invoked with two arguments.
**
** ^The first argument to the busy handler is a copy of the void* pointer which
** is the third argument to sqlite3_busy_handler().  ^The second argument to
** the busy handler callback is the number of times that the busy handler has
** been invoked for the same locking event.  ^If the
** been invoked previously for the same locking event.  ^If the
** busy callback returns 0, then no additional attempts are made to
** access the database and [SQLITE_BUSY] is returned
** to the application.
** ^If the callback returns non-zero, then another attempt
** is made to access the database and the cycle repeats.
**
** The presence of a busy handler does not guarantee that it will be invoked

** kind of [sqlite3_value] object can be used with this interface.
**
** If these routines are called from within the different thread
** than the one containing the application-defined function that received
** the [sqlite3_context] pointer, the results are undefined.
*/
void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_blob64(sqlite3_context*,const void*,sqlite3_uint64,void(*)(void*));
void sqlite3_result_blob64(sqlite3_context*,const void*,
                           sqlite3_uint64,void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_error_toobig(sqlite3_context*);
void sqlite3_result_error_nomem(sqlite3_context*);
void sqlite3_result_error_code(sqlite3_context*, int);
void sqlite3_result_int(sqlite3_context*, int);

** for a particular application.
*/
int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);

/*
** CAPI3REF: Checkpoint a database
**
** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X
** on [database connection] D to be [checkpointed].  ^If X is NULL or an
** empty string, then a checkpoint is run on all databases of
** connection D.  ^If the database connection D is not in
** [WAL | write-ahead log mode] then this interface is a harmless no-op.
** ^The [sqlite3_wal_checkpoint(D,X)] interface initiates a
** [sqlite3_wal_checkpoint_v2|PASSIVE] checkpoint.
** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
** Use the [sqlite3_wal_checkpoint_v2()] interface to get a FULL
** or RESET checkpoint.
**
** ^The [wal_checkpoint pragma] can be used to invoke this interface
** from SQL.  ^The [sqlite3_wal_autocheckpoint()] interface and the
** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 
** [write-ahead log] for database X on [database connection] D to be
** transferred into the database file and for the write-ahead log to
** be reset.  See the [checkpointing] documentation for addition
** [wal_autocheckpoint pragma] can be used to cause this interface to be
** run whenever the WAL reaches a certain size threshold.
** information.
**
** This interface used to be the only way to cause a checkpoint to
** occur.  But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
** interface was added.  This interface is retained for backwards
** compatibility and as a convenience for applications that need to manually
** start a callback but which do not need the full power (and corresponding
** See also: [sqlite3_wal_checkpoint_v2()]
** complication) of [sqlite3_wal_checkpoint_v2()].
*/
int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);

/*
** CAPI3REF: Checkpoint a database
**
** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
** Run a checkpoint operation on WAL database zDb attached to database 
** handle db. The specific operation is determined by the value of the 
** eMode parameter:
** operation on database X of [database connection] D in mode M.  Status
** information is written back into integers pointed to by L and C.)^
** ^(The M parameter must be a valid [checkpoint mode]:)^
**
** <dl>
** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
**   Checkpoint as many frames as possible without waiting for any database 
**   readers or writers to finish. Sync the db file if all frames in the log
**   ^Checkpoint as many frames as possible without waiting for any database 
**   readers or writers to finish, then sync the database file if all frames 
**   are checkpointed. This mode is the same as calling 
**   sqlite3_wal_checkpoint(). The [sqlite3_busy_handler|busy-handler callback]
**   is never invoked.
**   in the log were checkpointed. ^The [busy-handler callback]
**   is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.  
**   ^On the other hand, passive mode might leave the checkpoint unfinished
**   if there are concurrent readers or writers.
**
** <dt>SQLITE_CHECKPOINT_FULL<dd>
**   This mode blocks (it invokes the
**   ^This mode blocks (it invokes the
**   [sqlite3_busy_handler|busy-handler callback]) until there is no
**   database writer and all readers are reading from the most recent database
**   snapshot. It then checkpoints all frames in the log file and syncs the
**   database file. This call blocks database writers while it is running,
**   but not database readers.
**   snapshot. ^It then checkpoints all frames in the log file and syncs the
**   database file. ^This mode blocks new database writers while it is pending,
**   but new database readers are allowed to continue unimpeded.
**
** <dt>SQLITE_CHECKPOINT_RESTART<dd>
**   This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 
**   checkpointing the log file it blocks (calls the 
**   [sqlite3_busy_handler|busy-handler callback])
**   until all readers are reading from the database file only. This ensures 
**   that the next client to write to the database file restarts the log file 
**   from the beginning. This call blocks database writers while it is running,
**   but not database readers.
**   ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
**   that after checkpointing the log file it blocks (calls the 
**   [busy-handler callback])
**   until all readers are reading from the database file only. ^This ensures 
**   that the next writer will restart the log file from the beginning.
**   ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
**   database writer attempts while it is pending, but does not impede readers.
**
** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
**   ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
**   addition that it also truncates the log file to zero bytes just prior
**   to a successful return.
** </dl>
**
** If pnLog is not NULL, then *pnLog is set to the total number of frames in
** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to
** the total number of checkpointed frames (including any that were already
** checkpointed when this function is called). *pnLog and *pnCkpt may be
** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK.
** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
** the log file or to -1 if the checkpoint could not run because
** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
** log file (including any that were already checkpointed before the function
** was called) or to -1 if the checkpoint could not run due to an error or
** because the database is not in WAL mode. ^Note that upon successful
** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
** If no values are available because of an error, they are both set to -1
** before returning to communicate this to the caller.
** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
**
** All calls obtain an exclusive "checkpoint" lock on the database file. If
** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
** any other process is running a checkpoint operation at the same time, the 
** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 
** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 
** busy-handler configured, it will not be invoked in this case.
**
** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 
** "writer" lock on the database file. If the writer lock cannot be obtained
** immediately, and a busy-handler is configured, it is invoked and the writer
** lock retried until either the busy-handler returns 0 or the lock is
** successfully obtained. The busy-handler is also invoked while waiting for
** database readers as described above. If the busy-handler returns 0 before
** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 
** exclusive "writer" lock on the database file. ^If the writer lock cannot be
** obtained immediately, and a busy-handler is configured, it is invoked and
** the writer lock retried until either the busy-handler returns 0 or the lock
** is successfully obtained. ^The busy-handler is also invoked while waiting for
** database readers as described above. ^If the busy-handler returns 0 before
** the writer lock is obtained or while waiting for database readers, the
** checkpoint operation proceeds from that point in the same way as 
** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 
** without blocking any further. SQLITE_BUSY is returned in this case.
** without blocking any further. ^SQLITE_BUSY is returned in this case.
**
** If parameter zDb is NULL or points to a zero length string, then the
** specified operation is attempted on all WAL databases. In this case the
** values written to output parameters *pnLog and *pnCkpt are undefined. If 
** ^If parameter zDb is NULL or points to a zero length string, then the
** specified operation is attempted on all WAL databases [attached] to 
** [database connection] db.  In this case the
** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 
** an SQLITE_BUSY error is encountered when processing one or more of the 
** attached WAL databases, the operation is still attempted on any remaining 
** attached databases and SQLITE_BUSY is returned to the caller. If any other 
** attached databases and SQLITE_BUSY is returned at the end. ^If any other 
** error occurs while processing an attached database, processing is abandoned 
** and the error code returned to the caller immediately. If no error 
** and the error code is returned to the caller immediately. ^If no error 
** (SQLITE_BUSY or otherwise) is encountered while processing the attached 
** databases, SQLITE_OK is returned.
**
** If database zDb is the name of an attached database that is not in WAL
** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If
** ^If database zDb is the name of an attached database that is not in WAL
** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
** zDb is not NULL (or a zero length string) and is not the name of any
** attached database, SQLITE_ERROR is returned to the caller.
**
** ^Unless it returns SQLITE_MISUSE,
** the sqlite3_wal_checkpoint_v2() interface
** sets the error information that is queried by
** [sqlite3_errcode()] and [sqlite3_errmsg()].
**
** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
** from SQL.
*/
int sqlite3_wal_checkpoint_v2(
  sqlite3 *db,                    /* Database handle */
  const char *zDb,                /* Name of attached database (or NULL) */
  int eMode,                      /* SQLITE_CHECKPOINT_* value */
  int *pnLog,                     /* OUT: Size of WAL log in frames */
  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
);

/*
** CAPI3REF: Checkpoint operation parameters
** CAPI3REF: Checkpoint Mode Values
** KEYWORDS: {checkpoint mode}
**
** These constants can be used as the 3rd parameter to
** [sqlite3_wal_checkpoint_v2()].  See the [sqlite3_wal_checkpoint_v2()]
** documentation for additional information about the meaning and use of
** each of these values.
** These constants define all valid values for the "checkpoint mode" passed
** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
** meaning of each of these checkpoint modes.
*/
#define SQLITE_CHECKPOINT_PASSIVE 0
#define SQLITE_CHECKPOINT_FULL    1
#define SQLITE_CHECKPOINT_RESTART 2
#define SQLITE_CHECKPOINT_PASSIVE  0  /* Do as much as possible w/o blocking */
#define SQLITE_CHECKPOINT_FULL     1  /* Wait for writers, then checkpoint */
#define SQLITE_CHECKPOINT_RESTART  2  /* Like FULL but wait for for readers */
#define SQLITE_CHECKPOINT_TRUNCATE 3  /* Like RESTART but also truncate WAL */

/*
** CAPI3REF: Virtual Table Interface Configuration
**
** This function may be called by either the [xConnect] or [xCreate] method
** of a [virtual table] implementation to configure
** various facets of the virtual table interface.

**
** The following constants can be used for the T parameter to the
** [sqlite3_stmt_scanstatus(S,X,T,V)] interface.  Each constant designates a
** different metric for sqlite3_stmt_scanstatus() to return.
**
** <dl>
** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the
** total number of times that the X-th loop has run.</dd>
** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
** set to the total number of times that the X-th loop has run.</dd>
**
** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the
** total number of rows examined by all iterations of the X-th loop.</dd>
** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
** to the total number of rows examined by all iterations of the X-th loop.</dd>
**
** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
** <dd>^The "double" variable pointed to by the T parameter will be set to the
** query planner's estimate for the average number of rows output from each
** iteration of the X-th loop.  If the query planner's estimates was accurate,
** then this value will approximate the quotient NVISIT/NLOOP and the
** product of this value for all prior loops with the same SELECTID will
** be the NLOOP value for the current loop.
**
** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
** <dd>^The "const char *" variable pointed to by the T parameter will be set to 
** a zero-terminated UTF-8 string containing the name of the index or table used
** for the X-th loop.
** <dd>^The "const char *" variable pointed to by the T parameter will be set
** to a zero-terminated UTF-8 string containing the name of the index or table
** used for the X-th loop.
**
** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
** <dd>^The "const char *" variable pointed to by the T parameter will be set to 
** a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] description
** for the X-th loop.
** <dd>^The "const char *" variable pointed to by the T parameter will be set
** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
** description for the X-th loop.
**
** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
** <dd>^The "int" variable pointed to by the T parameter will be set to the
** "select-id" for the X-th loop.  The select-id identifies which query or
** subquery the loop is part of.  The main query has a select-id of zero.
** The select-id is the same value as is output in the first column
** of an [EXPLAIN QUERY PLAN] query.

/*
** CAPI3REF: Prepared Statement Scan Status
**
** Return status data for a single loop within query pStmt.
**
** The "iScanStatusOp" parameter determines which status information to return.
** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior of
** this interface is undefined.
** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
** of this interface is undefined.
** ^The requested measurement is written into a variable pointed to by
** the "pOut" parameter.
** Parameter "idx" identifies the specific loop to retrieve statistics for.
** Loops are numbered starting from zero. ^If idx is out of range - less than
** zero or greater than or equal to the total number of loops used to implement
** the statement - a non-zero value is returned and the variable that pOut
** points to is unchanged.

  AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
  Table *pTab;           /* Table for TK_COLUMN expressions. */
};

/*
** The following are the meanings of bits in the Expr.flags field.
*/
#define EP_FromJoin  0x000001 /* Originated in ON or USING clause of a join */
#define EP_FromJoin  0x000001 /* Originates in ON/USING clause of outer join */
#define EP_Agg       0x000002 /* Contains one or more aggregate functions */
#define EP_Resolved  0x000004 /* IDs have been resolved to COLUMNs */
#define EP_Error     0x000008 /* Expression contains one or more errors */
#define EP_Distinct  0x000010 /* Aggregate function with DISTINCT keyword */
#define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */
#define EP_DblQuoted 0x000040 /* token.z was originally in "..." */
#define EP_InfixFunc 0x000080 /* True for an infix function: LIKE, GLOB, etc */
#define EP_Collate   0x000100 /* Tree contains a TK_COLLATE operator */
#define EP_Generic   0x000200 /* Ignore COLLATE or affinity on this tree */
#define EP_IntValue  0x000400 /* Integer value contained in u.iValue */
#define EP_xIsSelect 0x000800 /* x.pSelect is valid (otherwise x.pList is) */
#define EP_Skip      0x001000 /* COLLATE, AS, or UNLIKELY */
#define EP_Reduced   0x002000 /* Expr struct EXPR_REDUCEDSIZE bytes only */
#define EP_TokenOnly 0x004000 /* Expr struct EXPR_TOKENONLYSIZE bytes only */
#define EP_Static    0x008000 /* Held in memory not obtained from malloc() */
#define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */
#define EP_NoReduce  0x020000 /* Cannot EXPRDUP_REDUCE this Expr */
#define EP_Unlikely  0x040000 /* unlikely() or likelihood() function */
#define EP_Constant  0x080000 /* Node is a constant */
#define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */

/*
** These macros can be used to test, set, or clear bits in the 
** Expr.flags field.
*/
#define ExprHasProperty(E,P)     (((E)->flags&(P))!=0)
#define ExprHasAllProperty(E,P)  (((E)->flags&(P))==(P))

  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3 *db;
  const char *zSql;
  char *zCopy = 0;                /* malloc() copy of zSql */
  int bytes;
  const char *zTail = 0;
  sqlite3_stmt *pStmt = 0;
  char zBuf[50];
  int rc;

  if( objc!=5 && objc!=4 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", 
       Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  zSql = Tcl_GetString(objv[2]);
  if( Tcl_GetIntFromObj(interp, objv[3], &bytes) ) return TCL_ERROR;

  /* Instead of using zSql directly, make a copy into a buffer obtained
  ** directly from malloc(). The idea is to make it easier for valgrind
  ** to spot buffer overreads.  */
  if( bytes>=0 ){
    zCopy = malloc(bytes);
    memcpy(zCopy, zSql, bytes);
  }else{
    int n = (int)strlen(zSql) + 1;
    zCopy = malloc(n);
    memcpy(zCopy, zSql, n);
  }
  rc = sqlite3_prepare_v2(db, zSql, bytes, &pStmt, objc>=5 ? &zTail : 0);
  rc = sqlite3_prepare_v2(db, zCopy, bytes, &pStmt, objc>=5 ? &zTail : 0);
  free(zCopy);
  zTail = &zSql[(zTail - zCopy)];

  assert(rc==SQLITE_OK || pStmt==0);
  Tcl_ResetResult(interp);
  if( sqlite3TestErrCode(interp, db, rc) ) return TCL_ERROR;
  if( zTail && objc>=5 ){
    if( bytes>=0 ){
      bytes = bytes - (int)(zTail-zSql);
    }

  int rc;

  int eMode;
  int nLog = -555;
  int nCkpt = -555;
  Tcl_Obj *pRet;

  const char * aMode[] = { "passive", "full", "restart", 0 };
  const char * aMode[] = { "passive", "full", "restart", "truncate", 0 };
  assert( SQLITE_CHECKPOINT_PASSIVE==0 );
  assert( SQLITE_CHECKPOINT_FULL==1 );
  assert( SQLITE_CHECKPOINT_RESTART==2 );
  assert( SQLITE_CHECKPOINT_TRUNCATE==3 );

  if( objc!=3 && objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB MODE ?NAME?");
    return TCL_ERROR;
  }

  if( objc==4 ){
    zDb = Tcl_GetString(objv[3]);
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db)
   || Tcl_GetIndexFromObj(interp, objv[2], aMode, "mode", 0, &eMode) 
  ){
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) || (
      TCL_OK!=Tcl_GetIntFromObj(0, objv[2], &eMode)
   && TCL_OK!=Tcl_GetIndexFromObj(interp, objv[2], aMode, "mode", 0, &eMode) 
  )){
    return TCL_ERROR;
  }

  rc = sqlite3_wal_checkpoint_v2(db, zDb, eMode, &nLog, &nCkpt);
  if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
    const char *zErrCode = sqlite3ErrName(rc);
    Tcl_SetResult(interp, (char *)sqlite3_errmsg(db), TCL_VOLATILE);
    Tcl_AppendResult(interp, zErrCode, " - ", (char *)sqlite3_errmsg(db), 0);
    return TCL_ERROR;
  }

  pRet = Tcl_NewObj();
  Tcl_ListObjAppendElement(interp, pRet, Tcl_NewIntObj(rc==SQLITE_BUSY?1:0));
  Tcl_ListObjAppendElement(interp, pRet, Tcl_NewIntObj(nLog));
  Tcl_ListObjAppendElement(interp, pRet, Tcl_NewIntObj(nCkpt));

  break;
}

#ifndef SQLITE_OMIT_WAL
/* Opcode: Checkpoint P1 P2 P3 * *
**
** Checkpoint database P1. This is a no-op if P1 is not currently in
** WAL mode. Parameter P2 is one of SQLITE_CHECKPOINT_PASSIVE, FULL
** or RESTART.  Write 1 or 0 into mem[P3] if the checkpoint returns
** WAL mode. Parameter P2 is one of SQLITE_CHECKPOINT_PASSIVE, FULL,
** RESTART, or TRUNCATE.  Write 1 or 0 into mem[P3] if the checkpoint returns
** SQLITE_BUSY or not, respectively.  Write the number of pages in the
** WAL after the checkpoint into mem[P3+1] and the number of pages
** in the WAL that have been checkpointed after the checkpoint
** completes into mem[P3+2].  However on an error, mem[P3+1] and
** mem[P3+2] are initialized to -1.
*/
case OP_Checkpoint: {
  int i;                          /* Loop counter */
  int aRes[3];                    /* Results */
  Mem *pMem;                      /* Write results here */

  assert( p->readOnly==0 );
  aRes[0] = 0;
  aRes[1] = aRes[2] = -1;
  assert( pOp->p2==SQLITE_CHECKPOINT_PASSIVE
       || pOp->p2==SQLITE_CHECKPOINT_FULL
       || pOp->p2==SQLITE_CHECKPOINT_RESTART
       || pOp->p2==SQLITE_CHECKPOINT_TRUNCATE
  );
  rc = sqlite3Checkpoint(db, pOp->p1, pOp->p2, &aRes[1], &aRes[2]);
  if( rc==SQLITE_BUSY ){
    rc = SQLITE_OK;
    aRes[0] = 1;
  }
  for(i=0, pMem = &aMem[pOp->p3]; i<3; i++, pMem++){

  if( p->aVar ){
    p->nVar = (ynVar)nVar;
    for(n=0; n<nVar; n++){
      p->aVar[n].flags = MEM_Null;
      p->aVar[n].db = db;
    }
  }
  if( p->azVar ){
  if( p->azVar && pParse->nzVar>0 ){
    p->nzVar = pParse->nzVar;
    memcpy(p->azVar, pParse->azVar, p->nzVar*sizeof(p->azVar[0]));
    memset(pParse->azVar, 0, pParse->nzVar*sizeof(pParse->azVar[0]));
  }
  if( p->aMem ){
    p->aMem--;                      /* aMem[] goes from 1..nMem */
    p->nMem = nMem;                 /*       not from 0..nMem-1 */

** messages to stderr that may be helpful in understanding the performance
** characteristics of the sorter in multi-threaded mode.
*/
#if 0
# define SQLITE_DEBUG_SORTER_THREADS 1
#endif

/*
** Hard-coded maximum amount of data to accumulate in memory before flushing
** to a level 0 PMA. The purpose of this limit is to prevent various integer
** overflows. 512MiB.
*/
#define SQLITE_MAX_MXPMASIZE    (1<<29)

/*
** Private objects used by the sorter
*/
typedef struct MergeEngine MergeEngine;     /* Merge PMAs together */
typedef struct PmaReader PmaReader;         /* Incrementally read one PMA */
typedef struct PmaWriter PmaWriter;         /* Incrementally write one PMA */
typedef struct SorterRecord SorterRecord;   /* A record being sorted */

      pTask->pSorter = pSorter;
    }

    if( !sqlite3TempInMemory(db) ){
      pSorter->mnPmaSize = SORTER_MIN_WORKING * pgsz;
      mxCache = db->aDb[0].pSchema->cache_size;
      if( mxCache<SORTER_MIN_WORKING ) mxCache = SORTER_MIN_WORKING;
      pSorter->mxPmaSize = mxCache * pgsz;
      pSorter->mxPmaSize = MIN((i64)mxCache*pgsz, SQLITE_MAX_MXPMASIZE);

      /* EVIDENCE-OF: R-26747-61719 When the application provides any amount of
      ** scratch memory using SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary
      ** large heap allocations.
      */
      if( sqlite3GlobalConfig.pScratch==0 ){
        assert( pSorter->iMemory==0 );

  assert( iDb>=0 );

  pTable->tabFlags |= TF_Virtual;
  pTable->nModuleArg = 0;
  addModuleArgument(db, pTable, sqlite3NameFromToken(db, pModuleName));
  addModuleArgument(db, pTable, 0);
  addModuleArgument(db, pTable, sqlite3DbStrDup(db, pTable->zName));
  assert( (pParse->sNameToken.z==pName2->z && pName2->z!=0)
       || (pParse->sNameToken.z==pName1->z && pName2->z==0)
  );
  pParse->sNameToken.n = (int)(&pModuleName->z[pModuleName->n] - pName1->z);
  pParse->sNameToken.n = (int)(
      &pModuleName->z[pModuleName->n] - pParse->sNameToken.z
  );

#ifndef SQLITE_OMIT_AUTHORIZATION
  /* Creating a virtual table invokes the authorization callback twice.
  ** The first invocation, to obtain permission to INSERT a row into the
  ** sqlite_master table, has already been made by sqlite3StartTable().
  ** The second call, to obtain permission to create the table, is made now.
  */

    walUnlockExclusive(pWal, WAL_READ_LOCK(0), 1);
    walIteratorFree(p->pIter);
    p->pIter = 0;
  }

  return p->rc;
}

/*
** The following is guaranteed when this function is called:
**
**   a) the WRITER lock is held,
**   b) the entire log file has been checkpointed, and
**   c) any existing readers are reading exclusively from the database
**      file - there are no readers that may attempt to read a frame from
**      the log file.
**
** This function updates the shared-memory structures so that the next
** client to write to the database (which may be this one) does so by
** writing frames into the start of the log file.
**
** The value of parameter salt1 is used as the aSalt[1] value in the 
** new wal-index header. It should be passed a pseudo-random value (i.e. 
** one obtained from sqlite3_randomness()).
*/
static void walRestartHdr(Wal *pWal, u32 salt1){
  volatile WalCkptInfo *pInfo = walCkptInfo(pWal);
  int i;                          /* Loop counter */
  u32 *aSalt = pWal->hdr.aSalt;   /* Big-endian salt values */
  pWal->nCkpt++;
  pWal->hdr.mxFrame = 0;
  sqlite3Put4byte((u8*)&aSalt[0], 1 + sqlite3Get4byte((u8*)&aSalt[0]));
  memcpy(&pWal->hdr.aSalt[1], &salt1, 4);
  walIndexWriteHdr(pWal);
  pInfo->nBackfill = 0;
  pInfo->aReadMark[1] = 0;
  for(i=2; i<WAL_NREADER; i++) pInfo->aReadMark[i] = READMARK_NOT_USED;
  assert( pInfo->aReadMark[0]==0 );
}

/*
** Copy as much content as we can from the WAL back into the database file
** in response to an sqlite3_wal_checkpoint() request or the equivalent.
**
** The amount of information copies from WAL to database might be limited
** by active readers.  This routine will never overwrite a database page

** The caller must be holding sufficient locks to ensure that no other
** checkpoint is running (in any other thread or process) at the same
** time.
*/
static int walCheckpoint(
  Wal *pWal,                      /* Wal connection */
  int eMode,                      /* One of PASSIVE, FULL or RESTART */
  int (*xBusyCall)(void*),        /* Function to call when busy */
  int (*xBusy)(void*),            /* Function to call when busy */
  void *pBusyArg,                 /* Context argument for xBusyHandler */
  int sync_flags,                 /* Flags for OsSync() (or 0) */
  u8 *zBuf,                       /* Temporary buffer to use */
  int nBuf                        /* Size of zBuf in bytes */
){
  int rc;                         /* Return code */
  int (*xBusy)(void*) = 0;        /* Function to call when waiting for locks */
  WalCkpt sC;

  /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked
  ** in the SQLITE_CHECKPOINT_PASSIVE mode. */
  if( eMode!=SQLITE_CHECKPOINT_PASSIVE ) xBusy = xBusyCall;
  assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );

  rc = walCheckpointStart(pWal, zBuf, nBuf, xBusy, pBusyArg, sync_flags, &sC);
  if( sC.pIter==0 ) goto walcheckpoint_out;
  assert( rc==SQLITE_OK );

  /* Step the checkpoint object until it reports something other than 
  ** SQLITE_OK.  */
  while( SQLITE_OK==(rc = walCheckpointStep(&sC)) );
  rc = walCheckpointFinalize(&sC);

  /* If this is an SQLITE_CHECKPOINT_RESTART operation, and the entire wal
  ** file has been copied into the database file, then block until all
  ** readers have finished using the wal file. This ensures that the next
  ** process to write to the database restarts the wal file.
  /* If this is an SQLITE_CHECKPOINT_RESTART or TRUNCATE operation, and the
  ** entire wal file has been copied into the database file, then block 
  ** until all readers have finished using the wal file. This ensures that 
  ** the next process to write to the database restarts the wal file.
  */
  if( rc==SQLITE_OK && eMode!=SQLITE_CHECKPOINT_PASSIVE ){
    assert( pWal->writeLock );
    if( sC.pInfo->nBackfill<pWal->hdr.mxFrame ){
      rc = SQLITE_BUSY;
    }else if( eMode==SQLITE_CHECKPOINT_RESTART ){
    }else if( eMode>=SQLITE_CHECKPOINT_RESTART ){
      u32 salt1;
      sqlite3_randomness(4, &salt1);
      assert( sC.mxSafeFrame==pWal->hdr.mxFrame );
      rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(1), WAL_NREADER-1);
      if( rc==SQLITE_OK ){
        if( eMode==SQLITE_CHECKPOINT_TRUNCATE ){
          /* IMPLEMENTATION-OF: R-44699-57140 This mode works the same way as
          ** SQLITE_CHECKPOINT_RESTART with the addition that it also
          ** truncates the log file to zero bytes just prior to a
          ** successful return.
          **
          ** In theory, it might be safe to do this without updating the
          ** wal-index header in shared memory, as all subsequent reader or
          ** writer clients should see that the entire log file has been
          ** checkpointed and behave accordingly. This seems unsafe though,
          ** as it would leave the system in a state where the contents of
          ** the wal-index header do not match the contents of the 
          ** file-system. To avoid this, update the wal-index header to
          ** indicate that the log file contains zero valid frames.  */
          walRestartHdr(pWal, salt1);
          rc = sqlite3OsTruncate(pWal->pWalFd, 0);
        }
        walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
      }
    }
  }

 walcheckpoint_out:
  walIteratorFree(sC.pIter);

    pWal->hdr.aFrameCksum[1] = aWalData[2];
    walCleanupHash(pWal);
  }

  return rc;
}


/*
** This function is called just before writing a set of frames to the log
** file (see sqlite3WalFrames()). It checks to see if, instead of appending
** to the current log file, it is possible to overwrite the start of the
** existing log file with the new frames (i.e. "reset" the log). If so,
** it sets pWal->hdr.mxFrame to 0. Otherwise, pWal->hdr.mxFrame is left
** unchanged.

        ** readers are currently using the WAL), then the transactions
        ** frames will overwrite the start of the existing log. Update the
        ** wal-index header to reflect this.
        **
        ** In theory it would be Ok to update the cache of the header only
        ** at this point. But updating the actual wal-index header is also
        ** safe and means there is no special case for sqlite3WalUndo()
        ** to handle if this transaction is rolled back.
        ** to handle if this transaction is rolled back.  */
        */
        int i;                    /* Loop counter */
        u32 *aSalt = pWal->hdr.aSalt;       /* Big-endian salt values */

        walRestartHdr(pWal, salt1);
        pWal->nCkpt++;
        pWal->hdr.mxFrame = 0;
        sqlite3Put4byte((u8*)&aSalt[0], 1 + sqlite3Get4byte((u8*)&aSalt[0]));
        aSalt[1] = salt1;
        walIndexWriteHdr(pWal);
        pInfo->nBackfill = 0;
        pInfo->aReadMark[1] = 0;
        for(i=2; i<WAL_NREADER; i++) pInfo->aReadMark[i] = READMARK_NOT_USED;
        assert( pInfo->aReadMark[0]==0 );
        walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
      }else if( rc!=SQLITE_BUSY ){
        return rc;
      }
    }
    walUnlockShared(pWal, WAL_READ_LOCK(0));
    pWal->readLock = -1;

** we can from WAL into the database.
**
** If parameter xBusy is not NULL, it is a pointer to a busy-handler
** callback. In this case this function runs a blocking checkpoint.
*/
int sqlite3WalCheckpoint(
  Wal *pWal,                      /* Wal connection */
  int eMode,                      /* PASSIVE, FULL or RESTART */
  int eMode,                      /* PASSIVE, FULL, RESTART, or TRUNCATE */
  int (*xBusy)(void*),            /* Function to call when busy */
  void *pBusyArg,                 /* Context argument for xBusyHandler */
  int sync_flags,                 /* Flags to sync db file with (or 0) */
  int nBuf,                       /* Size of temporary buffer */
  u8 *zBuf,                       /* Temporary buffer to use */
  int *pnLog,                     /* OUT: Number of frames in WAL */
  int *pnCkpt                     /* OUT: Number of backfilled frames in WAL */
){
  int rc;                         /* Return code */
  int isChanged = 0;              /* True if a new wal-index header is loaded */
  int eMode2 = eMode;             /* Mode to pass to walCheckpoint() */
  int (*xBusy2)(void*) = xBusy;   /* Busy handler for eMode2 */

  assert( pWal->ckptLock==0 );
  assert( pWal->writeLock==0 );

  /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked
  ** in the SQLITE_CHECKPOINT_PASSIVE mode. */
  assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );

  if( pWal->readOnly ) return SQLITE_READONLY;
  WALTRACE(("WAL%p: checkpoint begins\n", pWal));

  /* IMPLEMENTATION-OF: R-62028-47212 All calls obtain an exclusive 
  ** "checkpoint" lock on the database file. */
  rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1);
  if( rc ){
    /* Usually this is SQLITE_BUSY meaning that another thread or process
    ** is already running a checkpoint, or maybe a recovery.  But it might
    ** also be SQLITE_IOERR. */
    /* EVIDENCE-OF: R-10421-19736 If any other process is running a
    ** checkpoint operation at the same time, the lock cannot be obtained and
    ** SQLITE_BUSY is returned.
    ** EVIDENCE-OF: R-53820-33897 Even if there is a busy-handler configured,
    ** it will not be invoked in this case.
    */
    testcase( rc==SQLITE_BUSY );
    testcase( xBusy!=0 );
    return rc;
  }
  pWal->ckptLock = 1;

  /* IMPLEMENTATION-OF: R-59782-36818 The SQLITE_CHECKPOINT_FULL, RESTART and
  /* If this is a blocking-checkpoint, then obtain the write-lock as well
  ** TRUNCATE modes also obtain the exclusive "writer" lock on the database
  ** to prevent any writers from running while the checkpoint is underway.
  ** This has to be done before the call to walIndexReadHdr() below.
  ** file.
  **
  ** If the writer lock cannot be obtained, then a passive checkpoint is
  ** run instead. Since the checkpointer is not holding the writer lock,
  ** EVIDENCE-OF: R-60642-04082 If the writer lock cannot be obtained
  ** immediately, and a busy-handler is configured, it is invoked and the
  ** writer lock retried until either the busy-handler returns 0 or the
  ** there is no point in blocking waiting for any readers. Assuming no 
  ** other error occurs, this function will return SQLITE_BUSY to the caller.
  ** lock is successfully obtained.
  */
  if( eMode!=SQLITE_CHECKPOINT_PASSIVE ){
    rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_WRITE_LOCK, 1);
    if( rc==SQLITE_OK ){
      pWal->writeLock = 1;
    }else if( rc==SQLITE_BUSY ){
      eMode2 = SQLITE_CHECKPOINT_PASSIVE;
      xBusy2 = 0;
      rc = SQLITE_OK;
    }
  }

  /* Read the wal-index header. */
  if( rc==SQLITE_OK ){
    rc = walIndexReadHdr(pWal, &isChanged);
    if( isChanged && pWal->pDbFd->pMethods->iVersion>=3 ){
      sqlite3OsUnfetch(pWal->pDbFd, 0, 0);
    }
  }

  /* Copy data from the log to the database file. */
  if( rc==SQLITE_OK ){
    rc = walCheckpoint(pWal, eMode2, xBusy, pBusyArg, sync_flags, zBuf, nBuf);
    rc = walCheckpoint(pWal, eMode2, xBusy2, pBusyArg, sync_flags, zBuf, nBuf);

    /* If no error occurred, set the output variables. */
    if( rc==SQLITE_OK || rc==SQLITE_BUSY ){
      if( pnLog ) *pnLog = (int)pWal->hdr.mxFrame;
      if( pnCkpt ) *pnCkpt = (int)(walCkptInfo(pWal)->nBackfill);
    }
  }

      return 0;
    }
    memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
    if( pOld!=pWC->aStatic ){
      sqlite3DbFree(db, pOld);
    }
    pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
    memset(&pWC->a[pWC->nTerm], 0, sizeof(pWC->a[0])*(pWC->nSlot-pWC->nTerm));
  }
  pTerm = &pWC->a[idx = pWC->nTerm++];
  if( p && ExprHasProperty(p, EP_Unlikely) ){
    pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;
  }else{
    pTerm->truthProb = 1;
  }

  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
  int addrExplain                 /* Address of OP_Explain (or 0) */
){
  const char *zObj = 0;
  WhereLoop *pLoop = pLvl->pWLoop;
  if( (pLoop->wsFlags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
  if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0  &&  pLoop->u.btree.pIndex!=0 ){
    zObj = pLoop->u.btree.pIndex->zName;
  }else{
    zObj = pSrclist->a[pLvl->iFrom].zName;
  }
  sqlite3VdbeScanStatus(
      v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
  );

    */
    if( pWC->nTerm>1 ){
      int iTerm;
      for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
        Expr *pExpr = pWC->a[iTerm].pExpr;
        if( &pWC->a[iTerm] == pTerm ) continue;
        if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
        testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );
        if( (pWC->a[iTerm].wtFlags & TERM_VIRTUAL)!=0 ) continue;
        if( pWC->a[iTerm].wtFlags & (TERM_ORINFO|TERM_VIRTUAL) ) continue;
        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
      }
      if( pAndExpr ){
        pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0);
      }
    }

  return SQLITE_OK;
}

/*
** Adjust the WhereLoop.nOut value downward to account for terms of the
** WHERE clause that reference the loop but which are not used by an
** index.
*
** For every WHERE clause term that is not used by the index
** and which has a truth probability assigned by one of the likelihood(),
** likely(), or unlikely() SQL functions, reduce the estimated number
** of output rows by the probability specified.
**
** In the current implementation, the first extra WHERE clause term reduces
** the number of output rows by a factor of 10 and each additional term
** reduces the number of output rows by sqrt(2).
** TUNING:  For every WHERE clause term that is not used by the index
** and which does not have an assigned truth probability, heuristics
** described below are used to try to estimate the truth probability.
** TODO --> Perhaps this is something that could be improved by better
** table statistics.
**
** Heuristic 1:  Estimate the truth probability as 93.75%.  The 93.75%
** value corresponds to -1 in LogEst notation, so this means decrement
** the WhereLoop.nOut field for every such WHERE clause term.
**
** Heuristic 2:  If there exists one or more WHERE clause terms of the
** form "x==EXPR" and EXPR is not a constant 0 or 1, then make sure the
** final output row estimate is no greater than 1/4 of the total number
** of rows in the table.  In other words, assume that x==EXPR will filter
** out at least 3 out of 4 rows.  If EXPR is -1 or 0 or 1, then maybe the
** "x" column is boolean or else -1 or 0 or 1 is a common default value
** on the "x" column and so in that case only cap the output row estimate
** at 1/2 instead of 1/4.
*/
static void whereLoopOutputAdjust(
  WhereClause *pWC,      /* The WHERE clause */
  WhereLoop *pLoop,      /* The loop to adjust downward */
  LogEst nRow            /* Number of rows in the entire table */
){
  WhereTerm *pTerm, *pX;
  Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
  int i, j;
  int nEq = 0;    /* Number of = constraints not within likely()/unlikely() */
  int i, j, k;
  LogEst iReduce = 0;    /* pLoop->nOut should not exceed nRow-iReduce */

  assert( (pLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
  for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){
    if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break;
    if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;
    if( (pTerm->prereqAll & notAllowed)!=0 ) continue;
    for(j=pLoop->nLTerm-1; j>=0; j--){
      pX = pLoop->aLTerm[j];
      if( pX==0 ) continue;
      if( pX==pTerm ) break;
      if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break;
    }
    if( j<0 ){
      if( pTerm->truthProb<=0 ){
        /* If a truth probability is specified using the likelihood() hints,
        ** then use the probability provided by the application. */
        pLoop->nOut += pTerm->truthProb;
      }else{
        /* In the absence of explicit truth probabilities, use heuristics to
        ** guess a reasonable truth probability. */
        pLoop->nOut--;
        if( pTerm->eOperator&WO_EQ ) nEq++;
        if( pTerm->eOperator&WO_EQ ){
          Expr *pRight = pTerm->pExpr->pRight;
          if( sqlite3ExprIsInteger(pRight, &k) && k>=(-1) && k<=1 ){
            k = 10;
          }else{
            k = 20;
          }
          if( iReduce<k ) iReduce = k;
        }
      }
    }
  }
  /* TUNING:  If there is at least one equality constraint in the WHERE
  ** clause that does not have a likelihood() explicitly assigned to it
  ** then do not let the estimated number of output rows exceed half 
  ** the number of rows in the table. */
  if( nEq && pLoop->nOut>nRow-10 ){
    pLoop->nOut = nRow - 10;
  if( pLoop->nOut > nRow-iReduce )  pLoop->nOut = nRow - iReduce;
  }
}

/*
** Adjust the cost C by the costMult facter T.  This only occurs if
** compiled with -DSQLITE_ENABLE_COSTMULT
*/
#ifdef SQLITE_ENABLE_COSTMULT

  ORDER BY t1.ptime desc LIMIT 500;
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1x1 (ptime>?)} 0 1 1 {SEARCH TABLE t2 USING INDEX t2x0 (did=?)} 0 2 2 {SEARCH TABLE t3 USING INDEX t3x0 (uid=?)}}
#
# ^^^--- Before being fixed, the above was using an automatic covering
# on t3 and reordering the tables so that t3 was in the outer loop and
# implementing the ORDER BY clause using a B-Tree.

do_execsql_test autoindex2-120 {
  EXPLAIN QUERY PLAN
  SELECT
     t1_id,
     t1.did,
     param2,
     param3,
     t1.ptime,
     t1.trange,
     t1.exmass,
     t1.mass,
     t1.vstatus,
     type,
     subtype,
     t1.deviation,
     t1.formula,
     dparam1,
     reserve1,
     reserve2,
     param4,
     t1.last_operation,
     t1.admin_uuid,
     t1.previous_value,
     t1.job_id,
     client_did, 
     t1.last_t1,
     t1.data_t1,
     t1.previous_date,
     param5,
     param6,
     mgr_uuid
  FROM
     t3,
     t2,
     t1
  WHERE
     t1.ptime > 1393520400
     AND param3<>9001
     AND t3.flg7 = 1
     AND t1.did = t2.did
     AND t2.uid = t3.uid
  ORDER BY t1.ptime desc LIMIT 500;
} {0 0 2 {SEARCH TABLE t1 USING INDEX t1x1 (ptime>?)} 0 1 1 {SEARCH TABLE t2 USING INDEX t2x0 (did=?)} 0 2 0 {SEARCH TABLE t3 USING INDEX t3x0 (uid=?)}}

finish_test

# 2014 November 26
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix bigsort

#--------------------------------------------------------------------
# At one point there was an overflow problem if the product of the 
# cache-size and page-size was larger than 2^31. Causing an infinite 
# loop if the product was also an integer multiple of 2^32, or 
# inefficiency otherwise.
#
do_execsql_test 1.0 {
  PRAGMA page_size = 1024;
  CREATE TABLE t1(a, b);
  BEGIN;
  WITH data(x,y) AS (
    SELECT 1, zeroblob(10000)
    UNION ALL
    SELECT x+1, y FROM data WHERE x < 300000
  )
  INSERT INTO t1 SELECT * FROM data;
  COMMIT;
}
do_execsql_test 1.1 {
  PRAGMA cache_size = 4194304;
  CREATE INDEX i1 ON t1(a, b);
}


finish_test

# 2014-11-27
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file contains test cases for b-tree logic.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix btree01

# The refactoring on the b-tree balance() routine in check-in
# http://www.sqlite.org/src/info/face33bea1ba3a (2014-10-27)
# caused the integrity_check on the following SQL to fail.
#
do_execsql_test btree01-1.1 {
  PRAGMA page_size=65536;
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b BLOB);
  WITH RECURSIVE
     c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<30)
  INSERT INTO t1(a,b) SELECT i, zeroblob(6500) FROM c;
  UPDATE t1 SET b=zeroblob(3000);
  UPDATE t1 SET b=zeroblob(64000) WHERE a=2;
  PRAGMA integrity_check;
} {ok}

# The previous test is sufficient to prevent a regression.  But we
# add a number of additional tests to stress the balancer in similar
# ways, looking for related problems.
#
for {set i 1} {$i<=30} {incr i} {
  do_test btree01-1.2.$i {
    db eval {
      DELETE FROM t1;
      WITH RECURSIVE
        c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<30)
      INSERT INTO t1(a,b) SELECT i, zeroblob(6500) FROM c;
      UPDATE t1 SET b=zeroblob(3000);
      UPDATE t1 SET b=zeroblob(64000) WHERE a=$::i;
      PRAGMA integrity_check;
    }
  } {ok}
}
for {set i 1} {$i<=30} {incr i} {
  do_test btree01-1.3.$i {
    db eval {
      DELETE FROM t1;
      WITH RECURSIVE
        c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<30)
      INSERT INTO t1(a,b) SELECT i, zeroblob(6500) FROM c;
      UPDATE t1 SET b=zeroblob(2000);
      UPDATE t1 SET b=zeroblob(64000) WHERE a=$::i;
      PRAGMA integrity_check;
    }
  } {ok}
}
for {set i 1} {$i<=30} {incr i} {
  do_test btree01-1.4.$i {
    db eval {
      DELETE FROM t1;
      WITH RECURSIVE
        c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<30)
      INSERT INTO t1(a,b) SELECT i, zeroblob(6500) FROM c;
      UPDATE t1 SET b=zeroblob(6499) WHERE (a%3)==0;
      UPDATE t1 SET b=zeroblob(6499) WHERE (a%3)==1;
      UPDATE t1 SET b=zeroblob(6499) WHERE (a%3)==2;
      UPDATE t1 SET b=zeroblob(64000) WHERE a=$::i;
      PRAGMA integrity_check;
    }
  } {ok}
}
for {set i 1} {$i<=30} {incr i} {
  do_test btree01-1.5.$i {
    db eval {
      DELETE FROM t1;
      WITH RECURSIVE
        c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<30)
      INSERT INTO t1(a,b) SELECT i, zeroblob(6542) FROM c;
      UPDATE t1 SET b=zeroblob(2331);
      UPDATE t1 SET b=zeroblob(65496) WHERE a=$::i;
      PRAGMA integrity_check;
    }
  } {ok}
}
for {set i 1} {$i<=30} {incr i} {
  do_test btree01-1.6.$i {
    db eval {
      DELETE FROM t1;
      WITH RECURSIVE
        c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<30)
      INSERT INTO t1(a,b) SELECT i, zeroblob(6542) FROM c;
      UPDATE t1 SET b=zeroblob(2332);
      UPDATE t1 SET b=zeroblob(65496) WHERE a=$::i;
      PRAGMA integrity_check;
    }
  } {ok}
}
for {set i 1} {$i<=30} {incr i} {
  do_test btree01-1.7.$i {
    db eval {
      DELETE FROM t1;
      WITH RECURSIVE
        c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<30)
      INSERT INTO t1(a,b) SELECT i, zeroblob(6500) FROM c;
      UPDATE t1 SET b=zeroblob(1);
      UPDATE t1 SET b=zeroblob(65000) WHERE a=$::i;
      PRAGMA integrity_check;
    }
  } {ok}
}
for {set i 1} {$i<=31} {incr i} {
  do_test btree01-1.8.$i {
    db eval {
      DELETE FROM t1;
      WITH RECURSIVE
        c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<31)
      INSERT INTO t1(a,b) SELECT i, zeroblob(6500) FROM c;
      UPDATE t1 SET b=zeroblob(4000);
      UPDATE t1 SET b=zeroblob(65000) WHERE a=$::i;
      PRAGMA integrity_check;
    }
  } {ok}
}

finish_test

    SELECT DISTINCT
      CASE a WHEN 1 THEN x'0000000000'
             WHEN 2 THEN zeroblob(5)
             ELSE 'xyzzy' END
      FROM t1;
  SELECT quote(x) FROM t2 ORDER BY 1;
} {'xyzzy' X'0000000000'}

#----------------------------------------------------------------------------
# Ticket [c5ea805691bfc4204b1cb9e9aa0103bd48bc7d34] (2014-12-04)
# Make sure that DISTINCT works together with ORDER BY and descending
# indexes.
#
do_execsql_test 5.1 {
  DROP TABLE IF EXISTS t1;
  CREATE TABLE t1(x);
  INSERT INTO t1(x) VALUES(3),(1),(5),(2),(6),(4),(5),(1),(3);
  CREATE INDEX t1x ON t1(x DESC);
  SELECT DISTINCT x FROM t1 ORDER BY x ASC;
} {1 2 3 4 5 6}
do_execsql_test 5.2 {
  SELECT DISTINCT x FROM t1 ORDER BY x DESC;
} {6 5 4 3 2 1}
do_execsql_test 5.3 {
  SELECT DISTINCT x FROM t1 ORDER BY x;
} {1 2 3 4 5 6}
do_execsql_test 5.4 {
  DROP INDEX t1x;
  CREATE INDEX t1x ON t1(x ASC);
  SELECT DISTINCT x FROM t1 ORDER BY x ASC;
} {1 2 3 4 5 6}
do_execsql_test 5.5 {
  SELECT DISTINCT x FROM t1 ORDER BY x DESC;
} {6 5 4 3 2 1}
do_execsql_test 5.6 {
  SELECT DISTINCT x FROM t1 ORDER BY x;
} {1 2 3 4 5 6}

finish_test

# 2014 December 04
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
source $testdir/wal_common.tcl
set testprefix e_walckpt

# The following two commands are used to determine if any of the files
# "test.db", "test.db2" and "test.db3" are modified by a test case.
#
# The [save_db_hashes] command saves a hash of the current contents of
# all three files in global variables. The [compare_db_hashes] compares
# the current contents with the saved hashes and returns a list of the
# files that have changed.
#
proc save_db_hashes {} {
  global H
  foreach f {test.db test.db2 test.db3} {
    set H($f) 0
    catch { set H($f) [md5file $f] }
  }
}
proc compare_db_hashes {} {
  global H
  set ret [list]
  foreach f {test.db test.db2 test.db3} {
    set expect 0
    catch { set expect [md5file $f] }
    if {$H($f) != $expect} { lappend ret $f }
  }
  set ret
}


# The following tests are run 3 times, each using a different method of 
# invoking a checkpoint:
#
#   1) Using sqlite3_wal_checkpoint_v2()
#   2) Using "PRAGMA wal_checkpoint"
#   3) Using sqlite3_wal_checkpoint() in place of checkpoint_v2(PASSIVE)
#
# Cases (2) and (3) are to show that the following statements are 
# correct, respectively:
#
# EVIDENCE-OF: R-36706-10507 The PRAGMA wal_checkpoint command can be
# used to invoke this interface from SQL.
#
# EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is
# equivalent to
# sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0).
# 
foreach {tn script} {
  1 {
    proc checkpoint {db mode args} {
      eval sqlite3_wal_checkpoint_v2 [list $db] [list $mode] $args
    }
  }

  2 {
    proc checkpoint {db mode args} {
      set sql "PRAGMA wal_checkpoint"
      if {[llength $args] && [lindex $args 0]!=""} {
        set sql "PRAGMA [lindex $args 0].wal_checkpoint"
      }
      set rc [catch { $db eval $sql } msg]
      if {$rc} {
        regsub {database} $msg {database:} msg
        error "[sqlite3_errcode $db] - $msg"
      }
      set msg
    }
  }

  3 {
    proc checkpoint {db mode args} {
      if {$mode == "passive"} {
        set rc [eval sqlite3_wal_checkpoint [list $db] $args]
        if {$rc != "SQLITE_OK"} {
          error "$rc - [sqlite3_errmsg $db]"
        }
      } else {
        eval sqlite3_wal_checkpoint_v2 [list $db] [list $mode] $args
      }
    }
  }

} {

  eval $script

  reset_db
  forcedelete test.db2 test.db3 test.db4
  execsql {
    ATTACH 'test.db2' AS aux;
    ATTACH 'test.db3' AS aux2;
    ATTACH 'test.db4' AS aux3;
    CREATE TABLE t1(x);
    CREATE TABLE aux.t2(x);
    CREATE TABLE aux2.t3(x);
    CREATE TABLE aux3.t4(x);
    PRAGMA main.journal_mode = WAL;
    PRAGMA aux.journal_mode = WAL;
    PRAGMA aux2.journal_mode = WAL;
    /* Leave aux4 in rollback mode */
  }

  # EVIDENCE-OF: R-49787-09095 The sqlite3_wal_checkpoint_v2(D,X,M,L,C)
  # interface runs a checkpoint operation on database X of database
  # connection D in mode M. Status information is written back into
  # integers pointed to by L and C.
  #
  #     Tests 1, 2 and 3 below verify the "on database X" part of the
  #     above. Other parts of this requirement are tested below.
  #
  # EVIDENCE-OF: R-00653-06026 If parameter zDb is NULL or points to a
  # zero length string, then the specified operation is attempted on all
  # WAL databases attached to database connection db.
  #
  #     Tests 4 and 5 below test this.
  #
  foreach {tn2 zDb dblist} {
    1 main  test.db
    2 aux   test.db2
    3 aux2  test.db3
    4 ""    {test.db test.db2 test.db3}
    5 -     {test.db test.db2 test.db3}
    6 temp  {}
  } {
    do_test $tn.1.$tn2 {
      execsql {
        INSERT INTO t1 VALUES(1);
        INSERT INTO t2 VALUES(2);
        INSERT INTO t3 VALUES(3);
      }
      save_db_hashes

      if {$zDb == "-"} {
        checkpoint db passive
      } else {
        checkpoint db passive $zDb
      }

      compare_db_hashes
    } $dblist
  }

  # EVIDENCE-OF: R-38207-48996 If zDb is not NULL (or a zero length
  # string) and is not the name of any attached database, SQLITE_ERROR is
  # returned to the caller.
  do_test $tn.2.1 {
    list [catch { checkpoint db passive notadb } msg] $msg
  } {1 {SQLITE_ERROR - unknown database: notadb}}

  # EVIDENCE-OF: R-14303-42483 If database zDb is the name of an attached
  # database that is not in WAL mode, SQLITE_OK is returned and both
  # *pnLog and *pnCkpt set to -1.
  #
  if {$tn==3} {
    # With sqlite3_wal_checkpoint() the two output variables cannot be 
    # tested. So just test that no error is returned when attempting to
    # checkpoint a db in rollback mode.
    do_test $tn.2.2.a { checkpoint db passive aux3 } {}
  } else {
    do_test $tn.2.2.b { checkpoint db passive aux3 } {0 -1 -1}
  }

  # EVIDENCE-OF: R-62028-47212 All calls obtain an exclusive "checkpoint"
  # lock on the database file.
  db close
  testvfs tvfs
  tvfs filter xShmLock
  tvfs script filelock
  proc filelock {method file handle details} {
    # Test for an exclusive checkpoint lock. A checkpoint lock locks a
    # single byte starting at offset 1.
    if {$details == "1 1 lock exclusive"} { set ::seen_checkpoint_lock 1 }
  }
  sqlite3 db test.db -vfs tvfs
  do_test $tn.3.1 {
    execsql { INSERT INTO t1 VALUES('xyz') }
    unset -nocomplain ::seen_checkpoint_lock
    checkpoint db passive
    set ::seen_checkpoint_lock
  } {1}
  db close
  tvfs delete
  reset_db


 

  #-----------------------------------------------------------------------
  # EVIDENCE-OF: R-10421-19736 If any other process is running a
  # checkpoint operation at the same time, the lock cannot be obtained and
  # SQLITE_BUSY is returned.
  #
  # EVIDENCE-OF: R-53820-33897 Even if there is a busy-handler configured,
  # it will not be invoked in this case.
  #
  testvfs tvfs
  tvfs filter xWrite
  sqlite3 db test.db -vfs tvfs
  sqlite3 db2 test.db -vfs tvfs

  do_test $tn.3.2.1 {
    db2 eval {
      PRAGMA journal_mode = WAL;
      CREATE TABLE t1(x, y);
      INSERT INTO t1 VALUES(1,2);
      INSERT INTO t1 VALUES(3,4);
      INSERT INTO t1 VALUES(5,6);
    }
    file size test.db-wal
  } [wal_file_size 5 1024]


  # Connection [db] runs a checkpoint. During this checkpoint, each
  # time it calls xWrite() to write a page into the database file, we
  # attempt to start a checkpoint using [db2]. According to the 
  # first requirement being tested, this should return SQLITE_BUSY. According
  # to the second, the busy-handler belonging to [db2] should not be
  # invoked.
  #
  set ::write_count 0
  set ::write_errors [list]
  proc busy_callback {args} {
    lappend ::write_errors "busy handler called!"
  }
  proc write_callback {args} {
    set rc [catch {checkpoint db2 passive} msg]
    if {0==[regexp "database is locked" $msg] && $msg!="1 -1 -1"} {
      lappend ::write_errors "$rc $msg"
    } 
    incr ::write_count
  }
  db2 busy busy_callback
  tvfs script write_callback

  do_test $tn.3.2.2 {
    db eval {SELECT * FROM sqlite_master}
    checkpoint db full
    set ::write_count
  } {2}

  do_test $tn.3.2.3 {
    set ::write_errors
  } {}

  db close
  db2 close
  tvfs delete

}

#-----------------------------------------------------------------------
# EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
# mode:
#
#   Valid checkpoint modes are 0, 1, 2 and 3.
#
sqlite3 db test.db
foreach {tn mode res} {
  0 -1001    {1 {SQLITE_MISUSE - not an error}}
  1 -1       {1 {SQLITE_MISUSE - not an error}}
  2  0       {0 {0 -1 -1}}
  3  1       {0 {0 -1 -1}}
  4  2       {0 {0 -1 -1}}
  5  3       {0 {0 -1 -1}}
  6  4       {1 {SQLITE_MISUSE - not an error}}
  7  114     {1 {SQLITE_MISUSE - not an error}}
  8  1000000 {1 {SQLITE_MISUSE - not an error}}
} {
  do_test 4.$tn {
    list [catch "sqlite3_wal_checkpoint_v2 db $mode" msg] $msg
  } $res
}


finish_test

do_test join5-2.11 {
  execsql {SELECT * FROM xy LEFT JOIN ab ON 1 WHERE NULL}
} {}
do_test join5-2.12 {
  execsql {SELECT * FROM xy LEFT JOIN ab ON NULL WHERE NULL}
} {}

# Ticket https://www.sqlite.org/src/tktview/6f2222d550f5b0ee7ed37601
# Incorrect output on a LEFT JOIN.
#
do_execsql_test join5-3.1 {
  DROP TABLE IF EXISTS t1;
  DROP TABLE IF EXISTS t2;
  DROP TABLE IF EXISTS t3;
  CREATE TABLE x1(a);
  INSERT INTO x1 VALUES(1);
  CREATE TABLE x2(b NOT NULL);
  CREATE TABLE x3(c, d);
  INSERT INTO x3 VALUES('a', NULL);
  INSERT INTO x3 VALUES('b', NULL);
  INSERT INTO x3 VALUES('c', NULL);
  SELECT * FROM x1 LEFT JOIN x2 LEFT JOIN x3 ON x3.d = x2.b;
} {1 {} {} {}}
do_execsql_test join5-3.2 {
  DROP TABLE IF EXISTS t1;
  DROP TABLE IF EXISTS t2;
  DROP TABLE IF EXISTS t3;
  DROP TABLE IF EXISTS t4;
  DROP TABLE IF EXISTS t5;
  CREATE TABLE t1(x text NOT NULL, y text);
  CREATE TABLE t2(u text NOT NULL, x text NOT NULL);
  CREATE TABLE t3(w text NOT NULL, v text);
  CREATE TABLE t4(w text NOT NULL, z text NOT NULL);
  CREATE TABLE t5(z text NOT NULL, m text);
  INSERT INTO t1 VALUES('f6d7661f-4efe-4c90-87b5-858e61cd178b',NULL);
  INSERT INTO t1 VALUES('f6ea82c3-2cad-45ce-ae8f-3ddca4fb2f48',NULL);
  INSERT INTO t1 VALUES('f6f47499-ecb4-474b-9a02-35be73c235e5',NULL);
  INSERT INTO t1 VALUES('56f47499-ecb4-474b-9a02-35be73c235e5',NULL);
  INSERT INTO t3 VALUES('007f2033-cb20-494c-b135-a1e4eb66130c',
                        'f6d7661f-4efe-4c90-87b5-858e61cd178b');
  SELECT *
    FROM t3
         INNER JOIN t1 ON t1.x= t3.v AND t1.y IS NULL
         LEFT JOIN t4  ON t4.w = t3.w
         LEFT JOIN t5  ON t5.z = t4.z
         LEFT JOIN t2  ON t2.u = t5.m
         LEFT JOIN t1 xyz ON xyz.y = t2.x;
} {007f2033-cb20-494c-b135-a1e4eb66130c f6d7661f-4efe-4c90-87b5-858e61cd178b f6d7661f-4efe-4c90-87b5-858e61cd178b {} {} {} {} {} {} {} {} {}}
do_execsql_test join5-3.3 {
  DROP TABLE IF EXISTS x1;
  DROP TABLE IF EXISTS x2;
  DROP TABLE IF EXISTS x3;
  CREATE TABLE x1(a);
  INSERT INTO x1 VALUES(1);
  CREATE TABLE x2(b NOT NULL);
  CREATE TABLE x3(c, d);
  INSERT INTO x3 VALUES('a', NULL);
  INSERT INTO x3 VALUES('b', NULL);
  INSERT INTO x3 VALUES('c', NULL);
  SELECT * FROM x1 LEFT JOIN x2 JOIN x3 WHERE x3.d = x2.b;
} {}

finish_test

  speed1.test speed1p.test speed2.test speed3.test speed4.test 
  speed4p.test sqllimits1.test tkt2686.test thread001.test thread002.test
  thread003.test thread004.test thread005.test trans2.test vacuum3.test 
  incrvacuum_ioerr.test autovacuum_crash.test btree8.test shared_err.test
  vtab_err.test walslow.test walcrash.test walcrash3.test
  walthread.test rtree3.test indexfault.test securedel2.test
  sort3.test sort4.test fts4growth.test fts4growth2.test
  bigsort.test
}]
if {[info exists ::env(QUICKTEST_INCLUDE)]} {
  set allquicktests [concat $allquicktests $::env(QUICKTEST_INCLUDE)]
}

#############################################################################
# Start of tests

  PRAGMA foreign_keys=on;
}
do_execsql_test    4.2.1 { DELETE FROM p1 WHERE x=4 }
do_scanstatus_test 4.2.2 { 
  nLoop 1 nVisit 1 nEst 1.0 zName sqlite_autoindex_p1_1 
  zExplain {SEARCH TABLE p1 USING INDEX sqlite_autoindex_p1_1 (x=?)}

  nLoop 1 nVisit 3 nEst 524288.0 zName c1 zExplain {SCAN TABLE c1}
  nLoop 1 nVisit 3 nEst 262144.0 zName c1 zExplain {SCAN TABLE c1}
}

#-------------------------------------------------------------------------
# Further tests of different scan types.
#
reset_db
proc tochar {i} {

# 2014-12-05
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# Open two database connections on the same database in shared cache
# mode.  Hold one open while repeatedly closing, reopening, and using
# the second.
#
# This test is designed to demostrate that the fix for ticket
# [e4a18565a36884b00edf66541f38c693827968ab] works.  
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl
if {[run_thread_tests]==0} { finish_test ; return }
db close
set ::testprefix sharedB

set ::enable_shared_cache [sqlite3_enable_shared_cache 1]

#-------------------------------------------------------------------------
#
do_test 1.1 {
  sqlite3 db1 test.db
  sqlite3 db2 test.db

  db1 eval {
    CREATE TABLE t1(x,y TEXT COLLATE nocase);
    WITH RECURSIVE
      c(i) AS (VALUES(1) UNION ALL SELECT i+1 FROM c WHERE i<100)
    INSERT INTO t1(x,y) SELECT i, printf('x%03dy',i) FROM c;
    CREATE INDEX t1yx ON t1(y,x);
  }
  db2 eval {
    SELECT x FROM t1 WHERE y='X014Y';
  }
} {14}

for {set j 1} {$j<=100} {incr j} {
  do_test 1.2.$j {
    db2 close
    sqlite3 db2 test.db
    db2 eval {
      SELECT x FROM t1 WHERE y='X014Y';
    }
  } {14}
}

db1 close
db2 close
sqlite3_enable_shared_cache $::enable_shared_cache
finish_test

# invalid option
do_test shell1-1.1.1 {
  set res [catchcmd "-bad test.db" ""]
  set rc [lindex $res 0]
  list $rc \
       [regexp {Error: unknown option: -bad} $res]
} {1 1}
# error on extra options
do_test shell1-1.1.2 {
  set res [catchcmd "-bad test.db \"select 3\" \"select 4\"" ""]
do_test shell1-1.1.1b {
  set res [catchcmd "test.db -bad" ""]
  set rc [lindex $res 0]
  list $rc \
       [regexp {Error: too many options: "select 4"} $res]
       [regexp {Error: unknown option: -bad} $res]
} {1 1}
# error on extra options
do_test shell1-1.1.2 {
  catchcmd "test.db \"select 3\" \"select 4\"" ""
} {0 {3
4}}
# error on extra options
do_test shell1-1.1.3 {
  set res [catchcmd "-bad FOO test.db BAD" ".quit"]
  catchcmd "test.db FOO test.db BAD" ".quit"
  set rc [lindex $res 0]
  list $rc \
       [regexp {Error: too many options: "BAD"} $res]
} {1 {Error: near "FOO": syntax error}}
} {1 1}

# -help
do_test shell1-1.2.1 {
  set res [catchcmd "-help test.db" ""]
  set rc [lindex $res 0]
  list $rc \
       [regexp {Usage} $res] \
       [regexp {\-init} $res] \
       [regexp {\-version} $res]
} {1 1 1 1}

# -init filename       read/process named file
do_test shell1-1.3.1 {
  catchcmd "-init FOO test.db" ""
} {0 {}}
do_test shell1-1.3.2 {
  set res [catchcmd "-init FOO test.db .quit BAD" ""]
  set rc [lindex $res 0]
  list $rc \
       [regexp {Error: too many options: "BAD"} $res]
} {1 1}
  catchcmd "-init FOO test.db .quit BAD" ""
} {0 {}}
do_test shell1-1.3.3 {
  catchcmd "-init FOO test.db BAD .quit" ""
} {1 {Error: near "BAD": syntax error}}

# -echo                print commands before execution
do_test shell1-1.4.1 {
  catchcmd "-echo test.db" "" 
} {0 {}}

# -[no]header          turn headers on or off

  list $rc $fexist
} {{0 {}} 1}

# Shell silently ignores extra parameters.
# Ticket [f5cb008a65].
do_test shell2-1.2.1 {
  set rc [catch { eval exec $CLI \":memory:\" \"select 3\" \"select 4\" } msg]
  list $rc \
  list $rc $msg
       [regexp {Error: too many options: "select 4"} $msg]
} {1 1}
} {0 {3
4}}

# Test a problem reported on the mailing list. The shell was at one point
# returning the generic SQLITE_ERROR message ("SQL error or missing database")
# instead of the "too many levels..." message in the test below.
#
do_test shell2-1.3 {
  catchcmd "-batch test.db" {

do_execsql_test 21.2 {
  SELECT * FROM t9v WHERE a<b;
} {1 2 3}

do_execsql_test 21.3 {
  SELECT * FROM t9v WHERE a=b;
} {2 2 2}

#-------------------------------------------------------------------------
# At one point executing a CREATE VIRTUAL TABLE statement that specified 
# a database name but no virtual table arguments was causing an internal
# buffer overread. Valgrind would report errors while running the following 
# tests. Specifically:
#
#   CREATE VIRTUAL TABLE t1 USING fts4;          -- Ok - no db name.
#   CREATE VIRTUAL TABLE main.t1 USING fts4(x);  -- Ok - has vtab arguments.
#   CREATE VIRTUAL TABLE main.t1 USING fts4;     -- Had the problem. 
#
ifcapable fts3 {
  forcedelete test.db2
  set nm [string repeat abcdefghij 100]
  do_execsql_test 22.1 {
    ATTACH 'test.db2' AS $nm
  }
  
  execsql "SELECT * FROM sqlite_master"
  do_execsql_test 22.2 "CREATE VIRTUAL TABLE ${nm}.t1 USING fts4"
  
  do_test 22.3.1 {
    set sql "CREATE VIRTUAL TABLE ${nm}.t2 USING fts4"
    set stmt [sqlite3_prepare_v2 db $sql -1 dummy]
    sqlite3_step $stmt
  } {SQLITE_DONE}
  
  do_test 22.3.2 {
    sqlite3_finalize $stmt
  } {SQLITE_OK}
  
  do_test 22.4.1 {
    set sql "CREATE VIRTUAL TABLE ${nm}.t3 USING fts4"
    set n [string length $sql]
    set stmt [sqlite3_prepare db "${sql}xyz" $n dummy]
    sqlite3_step $stmt
  } {SQLITE_DONE}
  
  do_test 22.4.2 {
    sqlite3_finalize $stmt
  } {SQLITE_OK}
}

finish_test

    proc do_wal_checkpoint { dbhandle args } {
      set a(-mode) passive
      array set a $args
      foreach key [array names a] {
        if {[lsearch {-mode -db} $key]<0} { error "unknown switch: $key" }
      }

      set vals {restart full truncate}
      if {$a(-mode)!="restart" && $a(-mode)!="full"} { set a(-mode) passive }
      if {[lsearch -exact $vals $a(-mode)]<0} { set a(-mode) passive }

      set cmd [list sqlite3_wal_checkpoint_v2 $dbhandle $a(-mode)]
      if {[info exists a(-db)]} { lappend sql $a(-db) }

      uplevel $cmd
    }
  }

    6   FULL      3   {0 4 4}   2

    7   RESTART   -   {0 4 4}   3
    8   RESTART   1   {1 3 3}   1
    9   RESTART   2   {1 4 3}   2
    10  RESTART   3   {1 4 4}   3

    11  TRUNCATE  -   {0 0 0}   3
    12  TRUNCATE  1   {1 3 3}   1
    13  TRUNCATE  2   {1 4 3}   2
    14  TRUNCATE  3   {1 4 4}   3

  } {
    do_multiclient_test tn {
      setup_and_attach_aux

      proc busyhandler {x} {
        set ::max_busyhandler $x
        if {$::busy_on!="-" && $x==$::busy_on} { return 1 }

    code1 {sqlite3 db  test.db}
    code2 {sqlite3 db2 test.db}
    code3 {sqlite3 db3 test.db}

    do_test 3.$tn.5 { sql3 { PRAGMA journal_mode } } {wal}

    do_test 3.$tn.6 { code3 { do_wal_checkpoint db3 } } {0 0 0}
  }

  # Test SQLITE_CHECKPOINT_TRUNCATE.
  #
  do_multiclient_test tn {

    code1 $do_wal_checkpoint
    code2 $do_wal_checkpoint
    code3 $do_wal_checkpoint

    do_test 3.$tn.1 {
      sql1 {
        PRAGMA page_size = 1024;
        PRAGMA journal_mode = WAL;
        PRAGMA synchronous = normal;
        CREATE TABLE t1(x, y);
        CREATE INDEX i1 ON t1(x, y);
        INSERT INTO t1 VALUES(1, 2);
        INSERT INTO t1 VALUES(3, 4);
      }
      file size test.db-wal
    } [wal_file_size 8 1024]

    do_test 3.$tn.2 { do_wal_checkpoint db -mode truncate } {0 0 0}
    do_test 3.$tn.3 { file size test.db-wal } 0

    do_test 3.$tn.4 {
      sql2 { SELECT * FROM t1 }
    } {1 2 3 4}

    do_test 3.$tn.5 {
      sql2 { INSERT INTO t1 VALUES('a', 'b') }
      file size test.db-wal
    } [wal_file_size 2 1024]

  }
}


finish_test

  WHERE
     cx.code = '2990'
     AND cx.type=2
     AND px.cx_id = cx.cx_id
     AND px.px_tid = 0
     AND px.le_id = le.le_id;
} {/.*SCAN TABLE cx.*SEARCH TABLE px.*SEARCH TABLE le.*/}


# The following test is derived from a performance problem reported from
# the field.  Notice the multiple indexes with the same initial tables,
# and the unusual WHERE clause terms.
#
do_test 5.1 {
  set res [db eval {
    DROP TABLE IF EXISTS t1;
    CREATE TABLE t1(a,b,c,d,e,f,g,h);
    CREATE INDEX t1abc ON t1(a,b,c);
    CREATE INDEX t1abe ON t1(a,b,e);
    CREATE INDEX t1abf ON t1(a,b,f);
    ANALYZE;
    DROP TABLE IF EXISTS sqlite_stat4;
    DROP TABLE IF EXISTS sqlite_stat3;
    DELETE FROM sqlite_stat1;
    INSERT INTO sqlite_stat1(tbl,idx,stat)
      VALUES('t1','t1abc','2000000 8000 1600 800'),
            ('t1','t1abe','2000000 8000 1600 150'),
            ('t1','t1abf','2000000 8000 1600 150');
    ANALYZE sqlite_master;
  
    EXPLAIN QUERY PLAN
    SELECT * FROM t1
     WHERE (a=1 OR a=2)
       AND (b=3 OR b=4)
       AND (d>=5 AND d<=5)
       AND ((e>=7 AND e<=7) OR (f>=8 AND f<=8))
       AND g>0;
  }]
} {~/ANY/}
do_test 5.2 {set res} {/USING INDEX t1abe/}
do_test 5.3 {set res} {/USING INDEX t1abf/}



finish_test