** nSeg to nMin. If no level with at least nMin segments can be found, 
    ** set nSeg to -1.
    */
    rc = fts3SqlStmt(p, SQL_FIND_MERGE_LEVEL, &pFindLevel, 0);
    sqlite3_bind_int(pFindLevel, 1, MAX(2, nMin));
    if( sqlite3_step(pFindLevel)==SQLITE_ROW ){
      iAbsLevel = sqlite3_column_int64(pFindLevel, 0);
      if( nMin<2 ){
        nSeg = sqlite3_column_int(pFindLevel, 1);
      }else{
        nSeg = nMin;
      }

    }else{
      nSeg = -1;
    }
    rc = sqlite3_reset(pFindLevel);

    /* If the hint read from the %_stat table is not empty, check if the
    ** last entry in it specifies a relative level smaller than or equal
................................................................................
  /* If the first integer value is followed by a ',',  read the second
  ** integer value. */
  if( z[0]==',' && z[1]!='\0' ){
    z++;
    nMin = fts3Getint(&z);
  }

  if( z[0]!='\0' || nMin<0 || nMin==1 ){
    rc = SQLITE_ERROR;
  }else{
    rc = SQLITE_OK;
    if( !p->bHasStat ){
      assert( p->bFts4==0 );
      sqlite3Fts3CreateStatTable(&rc, p);
    }

    ** nSeg to nMin. If no level with at least nMin segments can be found, 
    ** set nSeg to -1.
    */
    rc = fts3SqlStmt(p, SQL_FIND_MERGE_LEVEL, &pFindLevel, 0);
    sqlite3_bind_int(pFindLevel, 1, MAX(2, nMin));
    if( sqlite3_step(pFindLevel)==SQLITE_ROW ){
      iAbsLevel = sqlite3_column_int64(pFindLevel, 0);

      nSeg = sqlite3_column_int(pFindLevel, 1);



      assert( nSeg>=2 );
    }else{
      nSeg = -1;
    }
    rc = sqlite3_reset(pFindLevel);

    /* If the hint read from the %_stat table is not empty, check if the
    ** last entry in it specifies a relative level smaller than or equal
................................................................................
  /* If the first integer value is followed by a ',',  read the second
  ** integer value. */
  if( z[0]==',' && z[1]!='\0' ){
    z++;
    nMin = fts3Getint(&z);
  }

  if( z[0]!='\0' || nMin<2 ){
    rc = SQLITE_ERROR;
  }else{
    rc = SQLITE_OK;
    if( !p->bHasStat ){
      assert( p->bFts4==0 );
      sqlite3Fts3CreateStatTable(&rc, p);
    }

# 2016 March 7
#
# 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.
#
#***********************************************************************
# Tests for RBU focused on the REPLACE operation (rbu_control column
# contains integer value 2).
#

source [file join [file dirname [info script]] rbu_common.tcl]
set ::testprefix rbuC

#-------------------------------------------------------------------------
# This test is actually of an UPDATE directive. Just to establish that
# these work with UNIQUE indexes before preceding to REPLACE.
#
do_execsql_test 1.0 {
  CREATE TABLE t1(i INTEGER PRIMARY KEY, a, b, c UNIQUE);
  INSERT INTO t1 VALUES(1, 'a', 'b', 'c');
}

forcedelete rbu.db
do_execsql_test 1.1 {
  ATTACH 'rbu.db' AS rbu;
  CREATE TABLE rbu.data_t1(i, a, b, c, rbu_control);
  INSERT INTO data_t1 VALUES(1, 'a', 'b', 'c', '.xxx');
}

do_test 1.2 {
  step_rbu test.db rbu.db
} {SQLITE_DONE}

do_execsql_test 1.3 {
  SELECT * FROM t1
} {
  1 a b c
}

#-------------------------------------------------------------------------
#
foreach {tn schema} {
  1 {
    CREATE TABLE t1(i INTEGER PRIMARY KEY, a, b, c UNIQUE);
    CREATE INDEX t1a ON t1(a);
  }
  2 {
    CREATE TABLE t1(i PRIMARY KEY, a, b, c UNIQUE);
    CREATE INDEX t1a ON t1(a);
  }
  3 {
    CREATE TABLE t1(i PRIMARY KEY, a, b, c UNIQUE) WITHOUT ROWID;
    CREATE INDEX t1a ON t1(a);
  }
} {
  reset_db
  forcedelete rbu.db
  execsql $schema

  do_execsql_test 2.$tn.0 {
    INSERT INTO t1 VALUES(1, 'a', 'b', 'c');
    INSERT INTO t1 VALUES(2, 'b', 'c', 'd');
    INSERT INTO t1 VALUES(3, 'c', 'd', 'e');
  }
  
  do_execsql_test 2.$tn.1 {
    ATTACH 'rbu.db' AS rbu;
    CREATE TABLE rbu.data_t1(i, a, b, c, rbu_control);
    INSERT INTO data_t1 VALUES(1, 1, 2, 3, 2);
    INSERT INTO data_t1 VALUES(3, 'c', 'd', 'e', 2);
    INSERT INTO data_t1 VALUES(4, 'd', 'e', 'f', 2);
  }
  
  do_test 2.$tn.2 {
    step_rbu test.db rbu.db
  } {SQLITE_DONE}
  
  do_execsql_test 2.$tn.3 {
    SELECT * FROM t1 ORDER BY i
  } {
    1 1 2 3
    2 b c d
    3 c d e
    4 d e f
  }
  
  integrity_check 2.$tn.4
}

foreach {tn schema} {
  1 {
    CREATE TABLE t1(a, b, c UNIQUE);
    CREATE INDEX t1a ON t1(a);
  }

  2 {
    CREATE VIRTUAL TABLE t1 USING fts5(a, b, c);
  }
} {
  if {$tn==2} { ifcapable !fts5 break }
  reset_db
  forcedelete rbu.db
  execsql $schema

  do_execsql_test 3.$tn.0 {
    INSERT INTO t1 VALUES('a', 'b', 'c');
    INSERT INTO t1 VALUES('b', 'c', 'd');
    INSERT INTO t1 VALUES('c', 'd', 'e');
  }
  
  do_execsql_test 3.$tn.1 {
    ATTACH 'rbu.db' AS rbu;
    CREATE TABLE rbu.data_t1(rbu_rowid, a, b, c, rbu_control);
    INSERT INTO data_t1 VALUES(1, 1, 2, 3, 2);
    INSERT INTO data_t1 VALUES(3, 'c', 'd', 'e', 2);
    INSERT INTO data_t1 VALUES(4, 'd', 'e', 'f', 2);
  }
  
  do_test 3.$tn.2 {
    step_rbu test.db rbu.db
  } {SQLITE_DONE}
  
  do_execsql_test 3.$tn.3 {
    SELECT rowid, * FROM t1 ORDER BY 1
  } {
    1 1 2 3
    2 b c d
    3 c d e
    4 d e f
  }
  
  integrity_check 3.$tn.4
}



finish_test

/*
** Within the RBU_STAGE_OAL stage, each call to sqlite3rbu_step() performs
** one of the following operations.
*/
#define RBU_INSERT     1          /* Insert on a main table b-tree */
#define RBU_DELETE     2          /* Delete a row from a main table b-tree */

#define RBU_IDX_DELETE 3          /* Delete a row from an aux. index b-tree */
#define RBU_IDX_INSERT 4          /* Insert on an aux. index b-tree */
#define RBU_UPDATE     5          /* Update a row in a main table b-tree */



/*
** A single step of an incremental checkpoint - frame iWalFrame of the wal
** file should be copied to page iDbPage of the database file.
*/
struct RbuFrame {
  u32 iDbPage;
................................................................................
          zSql = sqlite3_mprintf(
              "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' ORDER BY %s%s",
              zCollist, p->zStateDb, pIter->zDataTbl,
              zCollist, zLimit
          );
        }else{
          zSql = sqlite3_mprintf(
              "SELECT %s, rbu_control FROM '%q' "
              "WHERE typeof(rbu_control)='integer' AND rbu_control!=1 "
              "UNION ALL "
              "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' "

              "ORDER BY %s%s",
              zCollist, pIter->zDataTbl, 
              zCollist, p->zStateDb, pIter->zDataTbl, 
              zCollist, zLimit
          );
        }
        p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz, zSql);
      }

      sqlite3_free(zImposterCols);
................................................................................
            , (pIter->eType==RBU_PK_EXTERNAL ? ", 0 AS rbu_rowid" : "")
            , pIter->zDataTbl
        );

        rbuMPrintfExec(p, p->dbMain,
            "CREATE TEMP TRIGGER rbu_delete_tr BEFORE DELETE ON \"%s%w\" "
            "BEGIN "
            "  SELECT rbu_tmp_insert(2, %s);"
            "END;"

            "CREATE TEMP TRIGGER rbu_update1_tr BEFORE UPDATE ON \"%s%w\" "
            "BEGIN "
            "  SELECT rbu_tmp_insert(2, %s);"
            "END;"

            "CREATE TEMP TRIGGER rbu_update2_tr AFTER UPDATE ON \"%s%w\" "
            "BEGIN "
            "  SELECT rbu_tmp_insert(3, %s);"
            "END;",
            zWrite, zTbl, zOldlist,
            zWrite, zTbl, zOldlist,
            zWrite, zTbl, zNewlist
        );

        if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
................................................................................
static int rbuStepType(sqlite3rbu *p, const char **pzMask){
  int iCol = p->objiter.nCol;     /* Index of rbu_control column */
  int res = 0;                    /* Return value */

  switch( sqlite3_column_type(p->objiter.pSelect, iCol) ){
    case SQLITE_INTEGER: {
      int iVal = sqlite3_column_int(p->objiter.pSelect, iCol);
      if( iVal==0 ){
        res = RBU_INSERT;
      }else if( iVal==1 ){
        res = RBU_DELETE;
      }else if( iVal==2 ){

        res = RBU_IDX_DELETE;
      }else if( iVal==3 ){
        res = RBU_IDX_INSERT;
      }
      break;
    }

    case SQLITE_TEXT: {
      const unsigned char *z = sqlite3_column_text(p->objiter.pSelect, iCol);
      if( z==0 ){
................................................................................
static void assertColumnName(sqlite3_stmt *pStmt, int iCol, const char *zName){
  const char *zCol = sqlite3_column_name(pStmt, iCol);
  assert( 0==sqlite3_stricmp(zName, zCol) );
}
#else
# define assertColumnName(x,y,z)
#endif






























































/*
** This function does the work for an sqlite3rbu_step() call.
**
** The object-iterator (p->objiter) currently points to a valid object,
** and the input cursor (p->objiter.pSelect) currently points to a valid
** input row. Perform whatever processing is required and return.
................................................................................
** If no  error occurs, SQLITE_OK is returned. Otherwise, an error code
** and message is left in the RBU handle and a copy of the error code
** returned.
*/
static int rbuStep(sqlite3rbu *p){
  RbuObjIter *pIter = &p->objiter;
  const char *zMask = 0;
  int i;
  int eType = rbuStepType(p, &zMask);

  if( eType ){
    assert( eType!=RBU_UPDATE || pIter->zIdx==0 );

    if( pIter->zIdx==0 && eType==RBU_IDX_DELETE ){
      rbuBadControlError(p);
    }
    else if( 
        eType==RBU_INSERT 
     || eType==RBU_DELETE
     || eType==RBU_IDX_DELETE 
     || eType==RBU_IDX_INSERT
    ){
      sqlite3_value *pVal;
      sqlite3_stmt *pWriter;

      assert( eType!=RBU_UPDATE );
      assert( eType!=RBU_DELETE || pIter->zIdx==0 );

      if( eType==RBU_IDX_DELETE || eType==RBU_DELETE ){
        pWriter = pIter->pDelete;
      }else{
        pWriter = pIter->pInsert;

      }

      for(i=0; i<pIter->nCol; i++){
        /* If this is an INSERT into a table b-tree and the table has an
        ** explicit INTEGER PRIMARY KEY, check that this is not an attempt
        ** to write a NULL into the IPK column. That is not permitted.  */
        if( eType==RBU_INSERT 
         && pIter->zIdx==0 && pIter->eType==RBU_PK_IPK && pIter->abTblPk[i] 
         && sqlite3_column_type(pIter->pSelect, i)==SQLITE_NULL
        ){
          p->rc = SQLITE_MISMATCH;
          p->zErrmsg = sqlite3_mprintf("datatype mismatch");
          goto step_out;
        }

        if( eType==RBU_DELETE && pIter->abTblPk[i]==0 ){
          continue;
        }

        pVal = sqlite3_column_value(pIter->pSelect, i);
        p->rc = sqlite3_bind_value(pWriter, i+1, pVal);
        if( p->rc ) goto step_out;
      }
      if( pIter->zIdx==0
       && (pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE) 
      ){
        /* For a virtual table, or a table with no primary key, the 
        ** SELECT statement is:
        **
        **   SELECT <cols>, rbu_control, rbu_rowid FROM ....
        **
        ** Hence column_value(pIter->nCol+1).
        */
        assertColumnName(pIter->pSelect, pIter->nCol+1, "rbu_rowid");
        pVal = sqlite3_column_value(pIter->pSelect, pIter->nCol+1);
        p->rc = sqlite3_bind_value(pWriter, pIter->nCol+1, pVal);

      }
      if( p->rc==SQLITE_OK ){
        sqlite3_step(pWriter);
        p->rc = resetAndCollectError(pWriter, &p->zErrmsg);


      }
    }else{
      sqlite3_value *pVal;
      sqlite3_stmt *pUpdate = 0;
      assert( eType==RBU_UPDATE );
      rbuGetUpdateStmt(p, pIter, zMask, &pUpdate);
      if( pUpdate ){

        for(i=0; p->rc==SQLITE_OK && i<pIter->nCol; i++){
          char c = zMask[pIter->aiSrcOrder[i]];
          pVal = sqlite3_column_value(pIter->pSelect, i);
          if( pIter->abTblPk[i] || c!='.' ){
            p->rc = sqlite3_bind_value(pUpdate, i+1, pVal);
          }
        }
................................................................................
        if( p->rc==SQLITE_OK ){
          sqlite3_step(pUpdate);
          p->rc = resetAndCollectError(pUpdate, &p->zErrmsg);
        }
      }
    }
  }

 step_out:
  return p->rc;
}

/*
** Increment the schema cookie of the main database opened by p->dbMain.
*/
static void rbuIncrSchemaCookie(sqlite3rbu *p){

/*
** Within the RBU_STAGE_OAL stage, each call to sqlite3rbu_step() performs
** one of the following operations.
*/
#define RBU_INSERT     1          /* Insert on a main table b-tree */
#define RBU_DELETE     2          /* Delete a row from a main table b-tree */
#define RBU_REPLACE    3          /* Delete and then insert a row */
#define RBU_IDX_DELETE 4          /* Delete a row from an aux. index b-tree */
#define RBU_IDX_INSERT 5          /* Insert on an aux. index b-tree */


#define RBU_UPDATE     6          /* Update a row in a main table b-tree */

/*
** A single step of an incremental checkpoint - frame iWalFrame of the wal
** file should be copied to page iDbPage of the database file.
*/
struct RbuFrame {
  u32 iDbPage;
................................................................................
          zSql = sqlite3_mprintf(
              "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' ORDER BY %s%s",
              zCollist, p->zStateDb, pIter->zDataTbl,
              zCollist, zLimit
          );
        }else{
          zSql = sqlite3_mprintf(
              "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' "

              "UNION ALL "
              "SELECT %s, rbu_control FROM '%q' "
              "WHERE typeof(rbu_control)='integer' AND rbu_control!=1 "
              "ORDER BY %s%s",
              zCollist, p->zStateDb, pIter->zDataTbl, 
              zCollist, pIter->zDataTbl, 
              zCollist, zLimit
          );
        }
        p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz, zSql);
      }

      sqlite3_free(zImposterCols);
................................................................................
            , (pIter->eType==RBU_PK_EXTERNAL ? ", 0 AS rbu_rowid" : "")
            , pIter->zDataTbl
        );

        rbuMPrintfExec(p, p->dbMain,
            "CREATE TEMP TRIGGER rbu_delete_tr BEFORE DELETE ON \"%s%w\" "
            "BEGIN "
            "  SELECT rbu_tmp_insert(3, %s);"
            "END;"

            "CREATE TEMP TRIGGER rbu_update1_tr BEFORE UPDATE ON \"%s%w\" "
            "BEGIN "
            "  SELECT rbu_tmp_insert(3, %s);"
            "END;"

            "CREATE TEMP TRIGGER rbu_update2_tr AFTER UPDATE ON \"%s%w\" "
            "BEGIN "
            "  SELECT rbu_tmp_insert(4, %s);"
            "END;",
            zWrite, zTbl, zOldlist,
            zWrite, zTbl, zOldlist,
            zWrite, zTbl, zNewlist
        );

        if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){
................................................................................
static int rbuStepType(sqlite3rbu *p, const char **pzMask){
  int iCol = p->objiter.nCol;     /* Index of rbu_control column */
  int res = 0;                    /* Return value */

  switch( sqlite3_column_type(p->objiter.pSelect, iCol) ){
    case SQLITE_INTEGER: {
      int iVal = sqlite3_column_int(p->objiter.pSelect, iCol);
      switch( iVal ){
        case 0: res = RBU_INSERT;     break;

        case 1: res = RBU_DELETE;     break;

        case 2: res = RBU_REPLACE;    break;
        case 3: res = RBU_IDX_DELETE; break;

        case 4: res = RBU_IDX_INSERT; break;
      }
      break;
    }

    case SQLITE_TEXT: {
      const unsigned char *z = sqlite3_column_text(p->objiter.pSelect, iCol);
      if( z==0 ){
................................................................................
static void assertColumnName(sqlite3_stmt *pStmt, int iCol, const char *zName){
  const char *zCol = sqlite3_column_name(pStmt, iCol);
  assert( 0==sqlite3_stricmp(zName, zCol) );
}
#else
# define assertColumnName(x,y,z)
#endif

/*
** Argument eType must be one of RBU_INSERT, RBU_DELETE, RBU_IDX_INSERT or
** RBU_IDX_DELETE. This function performs the work of a single
** sqlite3rbu_step() call for the type of operation specified by eType.
*/
static void rbuStepOneOp(sqlite3rbu *p, int eType){
  RbuObjIter *pIter = &p->objiter;
  sqlite3_value *pVal;
  sqlite3_stmt *pWriter;
  int i;

  assert( p->rc==SQLITE_OK );
  assert( eType!=RBU_DELETE || pIter->zIdx==0 );

  if( eType==RBU_IDX_DELETE || eType==RBU_DELETE ){
    pWriter = pIter->pDelete;
  }else{
    pWriter = pIter->pInsert;
  }

  for(i=0; i<pIter->nCol; i++){
    /* If this is an INSERT into a table b-tree and the table has an
    ** explicit INTEGER PRIMARY KEY, check that this is not an attempt
    ** to write a NULL into the IPK column. That is not permitted.  */
    if( eType==RBU_INSERT 
     && pIter->zIdx==0 && pIter->eType==RBU_PK_IPK && pIter->abTblPk[i] 
     && sqlite3_column_type(pIter->pSelect, i)==SQLITE_NULL
    ){
      p->rc = SQLITE_MISMATCH;
      p->zErrmsg = sqlite3_mprintf("datatype mismatch");
      return;
    }

    if( eType==RBU_DELETE && pIter->abTblPk[i]==0 ){
      continue;
    }

    pVal = sqlite3_column_value(pIter->pSelect, i);
    p->rc = sqlite3_bind_value(pWriter, i+1, pVal);
    if( p->rc ) return;
  }
  if( pIter->zIdx==0
   && (pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE) 
  ){
    /* For a virtual table, or a table with no primary key, the 
    ** SELECT statement is:
    **
    **   SELECT <cols>, rbu_control, rbu_rowid FROM ....
    **
    ** Hence column_value(pIter->nCol+1).
    */
    assertColumnName(pIter->pSelect, pIter->nCol+1, "rbu_rowid");
    pVal = sqlite3_column_value(pIter->pSelect, pIter->nCol+1);
    p->rc = sqlite3_bind_value(pWriter, pIter->nCol+1, pVal);
  }
  if( p->rc==SQLITE_OK ){
    sqlite3_step(pWriter);
    p->rc = resetAndCollectError(pWriter, &p->zErrmsg);
  }
}

/*
** This function does the work for an sqlite3rbu_step() call.
**
** The object-iterator (p->objiter) currently points to a valid object,
** and the input cursor (p->objiter.pSelect) currently points to a valid
** input row. Perform whatever processing is required and return.
................................................................................
** If no  error occurs, SQLITE_OK is returned. Otherwise, an error code
** and message is left in the RBU handle and a copy of the error code
** returned.
*/
static int rbuStep(sqlite3rbu *p){
  RbuObjIter *pIter = &p->objiter;
  const char *zMask = 0;

  int eType = rbuStepType(p, &zMask);

  if( eType ){







    assert( eType==RBU_INSERT     || eType==RBU_DELETE
         || eType==RBU_REPLACE    || eType==RBU_IDX_DELETE
         || eType==RBU_IDX_INSERT || eType==RBU_UPDATE
    );



    assert( eType!=RBU_UPDATE || pIter->zIdx==0 );


    if( pIter->zIdx==0 && eType==RBU_IDX_DELETE ){



      rbuBadControlError(p);
    }





    else if( eType==RBU_REPLACE ){
















      if( pIter->zIdx==0 ) rbuStepOneOp(p, RBU_DELETE);












      if( p->rc==SQLITE_OK ) rbuStepOneOp(p, RBU_INSERT);
    }



    else if( eType!=RBU_UPDATE ){
      rbuStepOneOp(p, eType);
    }
    else{
      sqlite3_value *pVal;
      sqlite3_stmt *pUpdate = 0;
      assert( eType==RBU_UPDATE );
      rbuGetUpdateStmt(p, pIter, zMask, &pUpdate);
      if( pUpdate ){
        int i;
        for(i=0; p->rc==SQLITE_OK && i<pIter->nCol; i++){
          char c = zMask[pIter->aiSrcOrder[i]];
          pVal = sqlite3_column_value(pIter->pSelect, i);
          if( pIter->abTblPk[i] || c!='.' ){
            p->rc = sqlite3_bind_value(pUpdate, i+1, pVal);
          }
        }
................................................................................
        if( p->rc==SQLITE_OK ){
          sqlite3_step(pUpdate);
          p->rc = resetAndCollectError(pUpdate, &p->zErrmsg);
        }
      }
    }
  }


  return p->rc;
}

/*
** Increment the schema cookie of the main database opened by p->dbMain.
*/
static void rbuIncrSchemaCookie(sqlite3rbu *p){

                             sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
    sqlite3BtreeSetPagerFlags(aNew->pBt,
                      PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));
#endif
    sqlite3BtreeLeave(aNew->pBt);
  }
  aNew->safety_level = 3;
  aNew->zName = sqlite3DbStrDup(db, zName);
  if( rc==SQLITE_OK && aNew->zName==0 ){
    rc = SQLITE_NOMEM_BKPT;
  }


#ifdef SQLITE_HAS_CODEC

                             sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
    sqlite3BtreeSetPagerFlags(aNew->pBt,
                      PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));
#endif
    sqlite3BtreeLeave(aNew->pBt);
  }
  aNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
  aNew->zName = sqlite3DbStrDup(db, zName);
  if( rc==SQLITE_OK && aNew->zName==0 ){
    rc = SQLITE_NOMEM_BKPT;
  }


#ifdef SQLITE_HAS_CODEC

    ** file.
    */
    if( page1[19]==2 && (pBt->btsFlags & BTS_NO_WAL)==0 ){
      int isOpen = 0;
      rc = sqlite3PagerOpenWal(pBt->pPager, &isOpen);
      if( rc!=SQLITE_OK ){
        goto page1_init_failed;
      }else if( isOpen==0 ){
#ifdef SQLITE_DEFAULT_WAL_SAFETYLEVEL
        /* Default to specified safety_level for WAL mode */
        if( pBt->db!=0 && pBt->db->aDb!=0 ){
          int iDb;
          sqlite3 *db = pBt->db;



          Db *aDb = db->aDb;
          u8 level = 0;
          for(iDb=0; iDb<db->nDb; iDb++){
            if( aDb[iDb].pBt && aDb[iDb].pBt->pBt==pBt ) break;
          }
          assert( iDb<db->nDb );
          level = db->aDb[iDb].safety_level;
          if( !SQLITE_DbSafetyLevelIsFixed(level) && 
             (SQLITE_DbSafetyLevelValue(level) != SQLITE_DEFAULT_WAL_SAFETYLEVEL) ){
            aDb[iDb].safety_level = SQLITE_DEFAULT_WAL_SAFETYLEVEL;
            sqlite3PagerSetSafetyLevel(pBt->pPager, SQLITE_DEFAULT_WAL_SAFETYLEVEL, 
                                       (db->flags&SQLITE_FullFSync)!=0,
                                       (db->flags&SQLITE_CkptFullFSync)!=0);


          }
        }
#endif

        releasePage(pPage1);
        return SQLITE_OK;

      }
      rc = SQLITE_NOTADB;
    }
#endif

    /* EVIDENCE-OF: R-15465-20813 The maximum and minimum embedded payload
    ** fractions and the leaf payload fraction values must be 64, 32, and 32.

    ** file.
    */
    if( page1[19]==2 && (pBt->btsFlags & BTS_NO_WAL)==0 ){
      int isOpen = 0;
      rc = sqlite3PagerOpenWal(pBt->pPager, &isOpen);
      if( rc!=SQLITE_OK ){
        goto page1_init_failed;
      }else{
#if SQLITE_DEFAULT_SYNCHRONOUS!=SQLITE_DEFAULT_WAL_SYNCHRONOUS



        sqlite3 *db;
        Db *pDb;
        if( (db=pBt->db)!=0 && (pDb=db->aDb)!=0 ){
          while( pDb->pBt==0 || pDb->pBt->pBt!=pBt ){ pDb++; }
          if( pDb->bSyncSet==0
           && pDb->safety_level==SQLITE_DEFAULT_SYNCHRONOUS+1
          ){






            pDb->safety_level = SQLITE_DEFAULT_WAL_SYNCHRONOUS+1;



            sqlite3PagerSetFlags(pBt->pPager,
               pDb->safety_level | (db->flags & PAGER_FLAGS_MASK));
          }
        }
#endif
        if( isOpen==0 ){
          releasePage(pPage1);
          return SQLITE_OK;
        }
      }
      rc = SQLITE_NOTADB;
    }
#endif

    /* EVIDENCE-OF: R-15465-20813 The maximum and minimum embedded payload
    ** fractions and the leaf payload fraction values must be 64, 32, and 32.

  sqlite3BtreeLeave(db->aDb[0].pBt);
  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);

  /* The default safety_level for the main database is FULL; for the temp
  ** database it is OFF. This matches the pager layer defaults.  
  */
  db->aDb[0].zName = "main";
  db->aDb[0].safety_level = PAGER_SYNCHRONOUS_FULL;
  db->aDb[1].zName = "temp";
  db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;

  db->magic = SQLITE_MAGIC_OPEN;
  if( db->mallocFailed ){
    goto opendb_out;
  }

  sqlite3BtreeLeave(db->aDb[0].pBt);
  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);

  /* The default safety_level for the main database is FULL; for the temp
  ** database it is OFF. This matches the pager layer defaults.  
  */
  db->aDb[0].zName = "main";
  db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
  db->aDb[1].zName = "temp";
  db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;

  db->magic = SQLITE_MAGIC_OPEN;
  if( db->mallocFailed ){
    goto opendb_out;
  }

** The maximum allowed sector size. 64KiB. If the xSectorsize() method 
** returns a value larger than this, then MAX_SECTOR_SIZE is used instead.
** This could conceivably cause corruption following a power failure on
** such a system. This is currently an undocumented limit.
*/
#define MAX_SECTOR_SIZE 0x10000

/*
** If the option SQLITE_EXTRA_DURABLE option is set at compile-time, then
** SQLite will do extra fsync() operations when synchronous==FULL to help
** ensure that transactions are durable across a power failure.  Most
** applications are happy as long as transactions are consistent across
** a power failure, and are perfectly willing to lose the last transaction
** in exchange for the extra performance of avoiding directory syncs.
** And so the default SQLITE_EXTRA_DURABLE setting is off.
*/
#ifndef SQLITE_EXTRA_DURABLE
# define SQLITE_EXTRA_DURABLE 0
#endif


/*
** An instance of the following structure is allocated for each active
** savepoint and statement transaction in the system. All such structures
** are stored in the Pager.aSavepoint[] array, which is allocated and
** resized using sqlite3Realloc().
**
................................................................................
    assert( pPager->fullSync==0 );
    assert( pPager->extraSync==0 );
    assert( pPager->syncFlags==0 );
    assert( pPager->walSyncFlags==0 );
    assert( pPager->ckptSyncFlags==0 );
  }else{
    pPager->fullSync = 1;
#if SQLITE_EXTRA_DURABLE
    pPager->extraSync = 1;
#else
    pPager->extraSync = 0;
#endif
    pPager->syncFlags = SQLITE_SYNC_NORMAL;
    pPager->walSyncFlags = SQLITE_SYNC_NORMAL | WAL_SYNC_TRANSACTIONS;
    pPager->ckptSyncFlags = SQLITE_SYNC_NORMAL;
  }
  /* pPager->pFirst = 0; */
  /* pPager->pFirstSynced = 0; */
  /* pPager->pLast = 0; */

** The maximum allowed sector size. 64KiB. If the xSectorsize() method 
** returns a value larger than this, then MAX_SECTOR_SIZE is used instead.
** This could conceivably cause corruption following a power failure on
** such a system. This is currently an undocumented limit.
*/
#define MAX_SECTOR_SIZE 0x10000















/*
** An instance of the following structure is allocated for each active
** savepoint and statement transaction in the system. All such structures
** are stored in the Pager.aSavepoint[] array, which is allocated and
** resized using sqlite3Realloc().
**
................................................................................
    assert( pPager->fullSync==0 );
    assert( pPager->extraSync==0 );
    assert( pPager->syncFlags==0 );
    assert( pPager->walSyncFlags==0 );
    assert( pPager->ckptSyncFlags==0 );
  }else{
    pPager->fullSync = 1;



    pPager->extraSync = 0;

    pPager->syncFlags = SQLITE_SYNC_NORMAL;
    pPager->walSyncFlags = SQLITE_SYNC_NORMAL | WAL_SYNC_TRANSACTIONS;
    pPager->ckptSyncFlags = SQLITE_SYNC_NORMAL;
  }
  /* pPager->pFirst = 0; */
  /* pPager->pFirstSynced = 0; */
  /* pPager->pLast = 0; */

  return p;
}

/*
** Free an allocated buffer obtained from pcache1Alloc().
*/
static void pcache1Free(void *p){
  int nFreed = 0;
  if( p==0 ) return;
  if( SQLITE_WITHIN(p, pcache1.pStart, pcache1.pEnd) ){
    PgFreeslot *pSlot;
    sqlite3_mutex_enter(pcache1.mutex);
    sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_USED, 1);
    pSlot = (PgFreeslot*)p;
    pSlot->pNext = pcache1.pFree;
................................................................................
    pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;
    assert( pcache1.nFreeSlot<=pcache1.nSlot );
    sqlite3_mutex_leave(pcache1.mutex);
  }else{
    assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
    sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
#ifndef SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS

    nFreed = sqlite3MallocSize(p);
    sqlite3_mutex_enter(pcache1.mutex);
    sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_OVERFLOW, nFreed);
    sqlite3_mutex_leave(pcache1.mutex);

#endif
    sqlite3_free(p);
  }
}

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/*

  return p;
}

/*
** Free an allocated buffer obtained from pcache1Alloc().
*/
static void pcache1Free(void *p){

  if( p==0 ) return;
  if( SQLITE_WITHIN(p, pcache1.pStart, pcache1.pEnd) ){
    PgFreeslot *pSlot;
    sqlite3_mutex_enter(pcache1.mutex);
    sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_USED, 1);
    pSlot = (PgFreeslot*)p;
    pSlot->pNext = pcache1.pFree;
................................................................................
    pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;
    assert( pcache1.nFreeSlot<=pcache1.nSlot );
    sqlite3_mutex_leave(pcache1.mutex);
  }else{
    assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );
    sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
#ifndef SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS
    {
      int nFreed = sqlite3MallocSize(p);
      sqlite3_mutex_enter(pcache1.mutex);
      sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_OVERFLOW, nFreed);
      sqlite3_mutex_leave(pcache1.mutex);
    }
#endif
    sqlite3_free(p);
  }
}

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
/*

      }
    }
    if( eMode==PAGER_JOURNALMODE_QUERY && pId2->n==0 ){
      /* Convert "PRAGMA journal_mode" into "PRAGMA main.journal_mode" */
      iDb = 0;
      pId2->n = 1;
    }
#ifdef SQLITE_DEFAULT_WAL_SAFETYLEVEL
    if( ! SQLITE_DbSafetyLevelIsFixed(pDb->safety_level) ){
      if( eMode == PAGER_JOURNALMODE_WAL ){
        /* when entering wal mode, immediately switch the safety_level
        ** so that a query to pragma synchronous returns the correct value */
      
        pDb->safety_level = SQLITE_DEFAULT_WAL_SAFETYLEVEL;
      }else{
        /* If the user hasn't overridden the synchronous setting, use the 
        ** default for non-wal databases */
        pDb->safety_level = 3;
      }
    }
#endif /* SQLITE_DEFAULT_WAL_SAFETYLEVEL */
    for(ii=db->nDb-1; ii>=0; ii--){
      if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
        sqlite3VdbeUsesBtree(v, ii);
        sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
      }
    }
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
................................................................................
  ** Return or set the local value of the synchronous flag.  Changing
  ** the local value does not make changes to the disk file and the
  ** default value will be restored the next time the database is
  ** opened.
  */
  case PragTyp_SYNCHRONOUS: {
    if( !zRight ){
      returnSingleInt(v, "synchronous", 
            SQLITE_DbSafetyLevelValue(pDb->safety_level)-1);
    }else{
      if( !db->autoCommit ){
        sqlite3ErrorMsg(pParse, 
            "Safety level may not be changed inside a transaction");
      }else{
        int iLevel = (getSafetyLevel(zRight,0,1)+1)
                                      | SQLITE_SAFETYLEVEL_FIXED;
        iLevel &= PAGER_SYNCHRONOUS_MASK;
        if( iLevel==0 ) iLevel = 1;
        pDb->safety_level = iLevel;

        setAllPagerFlags(db);
      }
    }
    break;
  }
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

      }
    }
    if( eMode==PAGER_JOURNALMODE_QUERY && pId2->n==0 ){
      /* Convert "PRAGMA journal_mode" into "PRAGMA main.journal_mode" */
      iDb = 0;
      pId2->n = 1;
    }














    for(ii=db->nDb-1; ii>=0; ii--){
      if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
        sqlite3VdbeUsesBtree(v, ii);
        sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
      }
    }
    sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
................................................................................
  ** Return or set the local value of the synchronous flag.  Changing
  ** the local value does not make changes to the disk file and the
  ** default value will be restored the next time the database is
  ** opened.
  */
  case PragTyp_SYNCHRONOUS: {
    if( !zRight ){
      returnSingleInt(v, "synchronous", pDb->safety_level-1);

    }else{
      if( !db->autoCommit ){
        sqlite3ErrorMsg(pParse, 
            "Safety level may not be changed inside a transaction");
      }else{
        int iLevel = (getSafetyLevel(zRight,0,1)+1) & PAGER_SYNCHRONOUS_MASK;


        if( iLevel==0 ) iLevel = 1;
        pDb->safety_level = iLevel;
        pDb->bSyncSet = 1;
        setAllPagerFlags(db);
      }
    }
    break;
  }
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
** pointer types (i.e. FuncDef) defined above.
*/
#include "btree.h"
#include "vdbe.h"
#include "pager.h"
#include "pcache.h"

#include "os.h"
#include "mutex.h"

/* When using a default wal safety level, the safety level should only 
** change with the journal mode if the user hasn't manually specified 
** pragma synchronous, if they have the defaults shouldn't be applied.
** The SQLITE_SAFETYLEVEL_FIXED value is ORed into the Db->safety_level
** field when the user has specified a synchronous setting via pragma.
*/


#define SQLITE_SAFETYLEVEL_FIXED 0x10
#define SQLITE_SAFETYLEVEL_VALUE_MASK 0x07
#define SQLITE_DbSafetyLevelValue(level) (level&SQLITE_SAFETYLEVEL_VALUE_MASK)



#define SQLITE_DbSafetyLevelIsFixed(level) (level&SQLITE_SAFETYLEVEL_FIXED)





















/*
** Each database file to be accessed by the system is an instance
** of the following structure.  There are normally two of these structures
** in the sqlite.aDb[] array.  aDb[0] is the main database file and
** aDb[1] is the database file used to hold temporary tables.  Additional
** databases may be attached.
*/
struct Db {
  char *zName;         /* Name of this database */
  Btree *pBt;          /* The B*Tree structure for this database file */
  u8 safety_level;     /* How aggressive at syncing data to disk */

  Schema *pSchema;     /* Pointer to database schema (possibly shared) */
};

/*
** An instance of the following structure stores a database schema.
**
** Most Schema objects are associated with a Btree.  The exception is

** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
** pointer types (i.e. FuncDef) defined above.
*/
#include "btree.h"
#include "vdbe.h"
#include "pager.h"
#include "pcache.h"

#include "os.h"
#include "mutex.h"

/* The SQLITE_EXTRA_DURABLE compile-time option used to set the default
** synchronous setting to EXTRA.  It is no longer supported.



*/
#ifdef SQLITE_EXTRA_DURABLE
# warning Use SQLITE_DEFAULT_SYNCHRONOUS=3 instead of SQLITE_EXTRA_DURABLE
# define SQLITE_DEFAULT_SYNCHRONOUS 3


#endif

/*
** Default synchronous levels.
**
** Note that (for historcal reasons) the PAGER_SYNCHRONOUS_* macros differ
** from the SQLITE_DEFAULT_SYNCHRONOUS value by 1.
**
**           PAGER_SYNCHRONOUS       DEFAULT_SYNCHRONOUS
**   OFF           1                         0
**   NORMAL        2                         1
**   FULL          3                         2
**   EXTRA         4                         3
**
** The "PRAGMA synchronous" statement also uses the zero-based numbers.
** In other words, the zero-based numbers are used for all external interfaces
** and the one-based values are used internally.
*/
#ifndef SQLITE_DEFAULT_SYNCHRONOUS
# define SQLITE_DEFAULT_SYNCHRONOUS (PAGER_SYNCHRONOUS_FULL-1)
#endif
#ifndef SQLITE_DEFAULT_WAL_SYNCHRONOUS
# define SQLITE_DEFAULT_WAL_SYNCHRONOUS SQLITE_DEFAULT_SYNCHRONOUS
#endif

/*
** Each database file to be accessed by the system is an instance
** of the following structure.  There are normally two of these structures
** in the sqlite.aDb[] array.  aDb[0] is the main database file and
** aDb[1] is the database file used to hold temporary tables.  Additional
** databases may be attached.
*/
struct Db {
  char *zName;         /* Name of this database */
  Btree *pBt;          /* The B*Tree structure for this database file */
  u8 safety_level;     /* How aggressive at syncing data to disk */
  u8 bSyncSet;         /* True if "PRAGMA synchronous=N" has been run */
  Schema *pSchema;     /* Pointer to database schema (possibly shared) */
};

/*
** An instance of the following structure stores a database schema.
**
** Most Schema objects are associated with a Btree.  The exception is

  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  Tcl_CmdInfo cmdInfo;
  sqlite3 *db;
  int rc;
  char *zDb;

  char *zFile;
  char *zProc = 0;

  char *zErr = 0;

  if( objc!=4 && objc!=3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB-HANDLE FILE ?PROC?");
    return TCL_ERROR;
  }
  zDb = Tcl_GetString(objv[1]);

  zFile = Tcl_GetString(objv[2]);
  if( objc==4 ){
    zProc = Tcl_GetString(objv[3]);
  }


  /* Extract the C database handle from the Tcl command name */
  if( !Tcl_GetCommandInfo(interp, zDb, &cmdInfo) ){
    Tcl_AppendResult(interp, "command not found: ", zDb, (char*)0);
    return TCL_ERROR;
  }
  db = ((struct SqliteDb*)cmdInfo.objClientData)->db;

  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  Tcl_CmdInfo cmdInfo;
  sqlite3 *db;
  int rc;
  char *zDb;
#ifndef SQLITE_OMIT_LOAD_EXTENSION
  char *zFile;
  char *zProc = 0;
#endif
  char *zErr = 0;

  if( objc!=4 && objc!=3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB-HANDLE FILE ?PROC?");
    return TCL_ERROR;
  }
  zDb = Tcl_GetString(objv[1]);
#ifndef SQLITE_OMIT_LOAD_EXTENSION
  zFile = Tcl_GetString(objv[2]);
  if( objc==4 ){
    zProc = Tcl_GetString(objv[3]);
  }
#endif

  /* Extract the C database handle from the Tcl command name */
  if( !Tcl_GetCommandInfo(interp, zDb, &cmdInfo) ){
    Tcl_AppendResult(interp, "command not found: ", zDb, (char*)0);
    return TCL_ERROR;
  }
  db = ((struct SqliteDb*)cmdInfo.objClientData)->db;

  Tcl_SetVar2(interp,"sqlite_options","enable_purgeable_pcache","0",TCL_GLOBAL_ONLY);
#endif
#if SQLITE_DEFAULT_CKPTFULLFSYNC
  Tcl_SetVar2(interp,"sqlite_options","default_ckptfullfsync","1",TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","default_ckptfullfsync","0",TCL_GLOBAL_ONLY);
#endif
#if SQLITE_DEFAULT_WAL_SAFETYLEVEL
  Tcl_SetVar2(interp,"sqlite_options","default_wal_safetylevel",
              STRINGVALUE(SQLITE_DEFAULT_WAL_SAFETYLEVEL),TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","default_wal_safetylevel","0",TCL_GLOBAL_ONLY);
#endif
#if SQLITE_ENABLE_PERSIST_WAL
  Tcl_SetVar2(interp,"sqlite_options","enable_persist_wal","1",TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","enable_persist_wal","0",TCL_GLOBAL_ONLY);
#endif
    
#ifdef SQLITE_OMIT_SHARED_CACHE

  Tcl_SetVar2(interp,"sqlite_options","enable_purgeable_pcache","0",TCL_GLOBAL_ONLY);
#endif
#if SQLITE_DEFAULT_CKPTFULLFSYNC
  Tcl_SetVar2(interp,"sqlite_options","default_ckptfullfsync","1",TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","default_ckptfullfsync","0",TCL_GLOBAL_ONLY);
#endif






#if SQLITE_ENABLE_PERSIST_WAL
  Tcl_SetVar2(interp,"sqlite_options","enable_persist_wal","1",TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp,"sqlite_options","enable_persist_wal","0",TCL_GLOBAL_ONLY);
#endif
    
#ifdef SQLITE_OMIT_SHARED_CACHE

  PgHdr *pPage,               /* The page of the frame to be written */
  int nTruncate,              /* The commit flag.  Usually 0.  >0 for commit */
  sqlite3_int64 iOffset       /* Byte offset at which to write */
){
  int rc;                         /* Result code from subfunctions */
  void *pData;                    /* Data actually written */
#if defined(SQLITE_WRITE_WALFRAME_PREBUFFERED)
  void *aFrame;

  aFrame = p->aFrameBuf;
#else
  u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-header in */
#endif
  
#if defined(SQLITE_HAS_CODEC)
  if( (pData = sqlite3PagerCodec(pPage))==0 ) return SQLITE_NOMEM_BKPT;
#else

  PgHdr *pPage,               /* The page of the frame to be written */
  int nTruncate,              /* The commit flag.  Usually 0.  >0 for commit */
  sqlite3_int64 iOffset       /* Byte offset at which to write */
){
  int rc;                         /* Result code from subfunctions */
  void *pData;                    /* Data actually written */
#if defined(SQLITE_WRITE_WALFRAME_PREBUFFERED)


  u8 *aFrame = p->aFrameBuf;
#else
  u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-header in */
#endif
  
#if defined(SQLITE_HAS_CODEC)
  if( (pData = sqlite3PagerCodec(pPage))==0 ) return SQLITE_NOMEM_BKPT;
#else

  code2 { sqlite3 db test.db }

  foreach c {code1 code2} {
    $c {
      set v [split [db version] .]
      if {[llength $v]==3} {lappend v 0}
      set ::sqlite_libversion [format \
        "%d%.2d%.2d%2d" [lindex $v 0] [lindex $v 1] [lindex $v 2] [lindex $v 3]
      ]
    }
  }

  uplevel $script

  catch { code1 { db close } }
................................................................................
          SELECT level, group_concat(idx, ' ') FROM t2_segdir GROUP BY level;
        }
      } {0 {0 1 2 3 4 5}}

      if {[code1 { set ::sqlite_libversion }] >=3071200 
       && [code2 { set ::sqlite_libversion }] >=3071200 
      } {






        do_test backcompat-3.9 {
          sql1 { INSERT INTO t2(t2) VALUES('merge=100,4'); }
          sql2 { INSERT INTO t2(t2) VALUES('merge=100,4'); }
          sql1 { INSERT INTO t2(t2) VALUES('merge=100,4'); }
          sql2 { INSERT INTO t2(t2) VALUES('merge=2500,4'); }
          sql2 {
            SELECT level, group_concat(idx, ' ') FROM t2_segdir GROUP BY level;
          }
        } {0 {0 1} 1 0}

        do_test backcompat-3.10 {
          sql1 { INSERT INTO t2(t2) VALUES('integrity-check') }
          sql2 { INSERT INTO t2(t2) VALUES('integrity-check') }
        } {}
      }
    }

  code2 { sqlite3 db test.db }

  foreach c {code1 code2} {
    $c {
      set v [split [db version] .]
      if {[llength $v]==3} {lappend v 0}
      set ::sqlite_libversion [format \
        "%d%.2d%.2d%.2d" [lindex $v 0] [lindex $v 1] [lindex $v 2] [lindex $v 3]
      ]
    }
  }

  uplevel $script

  catch { code1 { db close } }
................................................................................
          SELECT level, group_concat(idx, ' ') FROM t2_segdir GROUP BY level;
        }
      } {0 {0 1 2 3 4 5}}

      if {[code1 { set ::sqlite_libversion }] >=3071200 
       && [code2 { set ::sqlite_libversion }] >=3071200 
      } {
        if {[code1 { set ::sqlite_libversion }]<3120000} {
          set res {0 {0 1} 1 0}
        } else {
          set res {1 0}
        }

        do_test backcompat-3.9 {
          sql1 { INSERT INTO t2(t2) VALUES('merge=100,4'); }
          sql2 { INSERT INTO t2(t2) VALUES('merge=100,4'); }
          sql1 { INSERT INTO t2(t2) VALUES('merge=100,4'); }
          sql2 { INSERT INTO t2(t2) VALUES('merge=2500,4'); }
          sql2 {
            SELECT level, group_concat(idx, ' ') FROM t2_segdir GROUP BY level;
          }
        } $res

        do_test backcompat-3.10 {
          sql1 { INSERT INTO t2(t2) VALUES('integrity-check') }
          sql2 { INSERT INTO t2(t2) VALUES('integrity-check') }
        } {}
      }
    }

  } {
    execsql { INSERT INTO x1 VALUES($L) }
  }
  execsql { 
    INSERT INTO x1(x1) VALUES('merge=4,4');
    SELECT level, end_block, length(root) FROM x1_segdir;
  }
} {0 {0 110} 110 0 {0 132} 132 0 {0 129} 129 1 {128 658} 2}

do_execsql_test 1.5 {
  SELECT length(block) FROM x1_segments;
} {658 {}}

do_test 1.6 {
  foreach L {
    {'Twas Mulga Bill, from Eaglehawk, that sought his own abode,}
    {That perched above Dead Man's Creek, beside the mountain road.}
    {He turned the cycle down the hill and mounted for the fray,}
    {But 'ere he'd gone a dozen yards it bolted clean away.}

    {It left the track, and through the trees, just like a silver steak,}
    {It whistled down the awful slope towards the Dead Man's Creek.}
    {It shaved a stump by half an inch, it dodged a big white-box:}
    {The very wallaroos in fright went scrambling up the rocks,}

    {The wombats hiding in their caves dug deeper underground,}
    {As Mulga Bill, as white as chalk, sat tight to every bound.}
    {It struck a stone and gave a spring that cleared a fallen tree,}
    {It raced beside a precipice as close as close could be;}

    {And then as Mulga Bill let out one last despairing shriek}
    {It made a leap of twenty feet into the Dead Man's Creek.}



  } {
    execsql { INSERT INTO x1 VALUES($L) }
  }
  execsql { 
    SELECT level, end_block, length(root) FROM x1_segdir;
  }
} {1 {128 658} 2 1 {130 1377} 6 0 {0 117} 117}

do_execsql_test 1.7 {
  SELECT sum(length(block)) FROM x1_segments WHERE blockid IN (129, 130);
} {1377}

#-------------------------------------------------------------------------
#
do_execsql_test 2.1 { 
  CREATE TABLE t1(docid, words);
  CREATE VIRTUAL TABLE x2 USING fts4;
}
................................................................................

do_execsql_test 2.5 { 
  SELECT end_block FROM x2_segdir WHERE level=3;
  INSERT INTO x2(x2) VALUES('merge=4,4');
  SELECT end_block FROM x2_segdir WHERE level=3;
  INSERT INTO x2(x2) VALUES('merge=4,4');
  SELECT end_block FROM x2_segdir WHERE level=3;
} {{3828 -3430} {3828 -10191} {3828 -14109}}

do_execsql_test 2.6 {
  SELECT sum(length(block)) FROM x2_segdir, x2_segments WHERE 
    blockid BETWEEN start_block AND leaves_end_block
    AND level=3
} {14109}

do_execsql_test 2.7 { 
  INSERT INTO x2(x2) VALUES('merge=1000,4');
  SELECT end_block FROM x2_segdir WHERE level=3;
} {{3828 86120}}

do_execsql_test 2.8 {
  SELECT sum(length(block)) FROM x2_segdir, x2_segments WHERE 
    blockid BETWEEN start_block AND leaves_end_block
    AND level=3
} {86120}

#--------------------------------------------------------------------------
# Test that delete markers are removed from FTS segments when possible.
# It is only possible to remove delete markers when the output of the
# merge operation will become the oldest segment in the index.
#
#   3.1 - when the oldest segment is created by an 'optimize'.
................................................................................

do_execsql_test 7.2 {
  INSERT INTO x6(x6) VALUES('merge=25,4');
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 {16014 -51226}
}

do_execsql_test 7.3 {
  UPDATE x6_segdir SET end_block = first(end_block) WHERE level=1;
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 16014
}

do_execsql_test 7.4 {
  INSERT INTO x6(x6) VALUES('merge=25,4');
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 16014
}

do_execsql_test 7.5 {
  INSERT INTO x6(x6) VALUES('merge=2500,4');
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {598 118006} 0 1 {718 118006} 1 0 16014
}

do_execsql_test 7.6 {
  INSERT INTO x6(x6) VALUES('merge=2500,2');
  SELECT level, idx, start_block, leaves_end_block, end_block FROM x6_segdir;
} {
  2 0 23695 24147 {41262 633507}
}

do_execsql_test 7.7 {
  SELECT sum(length(block)) FROM x6_segments 
  WHERE blockid BETWEEN 23695 AND 24147
} {633507}



finish_test

  } {
    execsql { INSERT INTO x1 VALUES($L) }
  }
  execsql { 
    INSERT INTO x1(x1) VALUES('merge=4,4');
    SELECT level, end_block, length(root) FROM x1_segdir;
  }
} {1 {224 921} 2}

do_execsql_test 1.5 {
  SELECT length(block) FROM x1_segments;
} {921 {}}

do_test 1.6 {
  foreach L {
    {'Twas Mulga Bill, from Eaglehawk, that sought his own abode,}
    {That perched above Dead Man's Creek, beside the mountain road.}
    {He turned the cycle down the hill and mounted for the fray,}
    {But 'ere he'd gone a dozen yards it bolted clean away.}

    {It left the track, and through the trees, just like a silver steak,}
    {It whistled down the awful slope towards the Dead Man's Creek.}
    {It shaved a stump by half an inch, it dodged a big white-box:}
    {The very wallaroos in fright went scrambling up the rocks,}

    {The wombats hiding in their caves dug deeper underground,}
    {As Mulga Bill, as white as chalk, sat tight to every bound.}
    {It struck a stone and gave a spring that cleared a fallen tree,}
    {It raced beside a precipice as close as close could be;}

    {And then as Mulga Bill let out one last despairing shriek}
    {It made a leap of twenty feet into the Dead Man's Creek.}
    {It shaved a stump by half an inch, it dodged a big white-box:}
    {The very wallaroos in fright went scrambling up the rocks,}
    {The wombats hiding in their caves dug deeper underground,}
  } {
    execsql { INSERT INTO x1 VALUES($L) }
  }
  execsql { 
    SELECT level, end_block, length(root) FROM x1_segdir;
  }
} {1 {224 921} 2 1 {226 1230} 7 0 {0 98} 98}

do_execsql_test 1.7 {
  SELECT sum(length(block)) FROM x1_segments WHERE blockid IN (224,225,226)
} {1230}

#-------------------------------------------------------------------------
#
do_execsql_test 2.1 { 
  CREATE TABLE t1(docid, words);
  CREATE VIRTUAL TABLE x2 USING fts4;
}
................................................................................

do_execsql_test 2.5 { 
  SELECT end_block FROM x2_segdir WHERE level=3;
  INSERT INTO x2(x2) VALUES('merge=4,4');
  SELECT end_block FROM x2_segdir WHERE level=3;
  INSERT INTO x2(x2) VALUES('merge=4,4');
  SELECT end_block FROM x2_segdir WHERE level=3;
} {{5588 -3950} {5588 -11766} {5588 -15541}}

do_execsql_test 2.6 {
  SELECT sum(length(block)) FROM x2_segdir, x2_segments WHERE 
    blockid BETWEEN start_block AND leaves_end_block
    AND level=3
} {15541}

do_execsql_test 2.7 { 
  INSERT INTO x2(x2) VALUES('merge=1000,4');
  SELECT end_block FROM x2_segdir WHERE level=3;
} {{5588 127563}}

do_execsql_test 2.8 {
  SELECT sum(length(block)) FROM x2_segdir, x2_segments WHERE 
    blockid BETWEEN start_block AND leaves_end_block
    AND level=3
} {127563}

#--------------------------------------------------------------------------
# Test that delete markers are removed from FTS segments when possible.
# It is only possible to remove delete markers when the output of the
# merge operation will become the oldest segment in the index.
#
#   3.1 - when the oldest segment is created by an 'optimize'.
................................................................................

do_execsql_test 7.2 {
  INSERT INTO x6(x6) VALUES('merge=25,4');
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 {23694 -69477}
}

do_execsql_test 7.3 {
  UPDATE x6_segdir SET end_block = first(end_block) WHERE level=1;
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 23694
}

do_execsql_test 7.4 {
  INSERT INTO x6(x6) VALUES('merge=25,4');
  SELECT level, idx, end_block FROM x6_segdir;
} {
  0 0 {118 117483} 0 1 {238 118006} 0 2 {358 118006} 
  0 3 {478 118006} 0 4 {598 118006} 0 5 {718 118006}
  1 0 23694
}

do_execsql_test 7.5 {
  INSERT INTO x6(x6) VALUES('merge=2500,4');
  SELECT level, idx, start_block, leaves_end_block, end_block FROM x6_segdir;
} {
  1 0 719 1171 23694
}

do_execsql_test 7.6 {
  INSERT INTO x6(x6) VALUES('merge=2500,2');
  SELECT level, idx, start_block, leaves_end_block, end_block FROM x6_segdir;
} {
  1 0 719 1171 23694
}

do_execsql_test 7.7 {
  SELECT sum(length(block)) FROM x6_segments 

} {635247}



finish_test

    INSERT INTO t6(t6) VALUES('merge=100,3');
    SELECT docid FROM t6 WHERE t6 MATCH '"zero zero"' AND lid=$lid;
  } {1 2 5}

  do_execsql_test 5.4.$lid.5 {
    SELECT count(*) FROM t6_segdir;
    SELECT count(*) FROM t6_segments;
  } {4 4}
}
finish_test

    INSERT INTO t6(t6) VALUES('merge=100,3');
    SELECT docid FROM t6 WHERE t6 MATCH '"zero zero"' AND lid=$lid;
  } {1 2 5}

  do_execsql_test 5.4.$lid.5 {
    SELECT count(*) FROM t6_segdir;
    SELECT count(*) FROM t6_segments;
  } {1 2}
}
finish_test

      SELECT docid FROM t1 WHERE t1 MATCH 'zero one two three'
    } {123 132 213 231 312 321}
  }
  
  do_execsql_test 1.3 { 
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level 
  } {
    0 {0 1 2 3} 
    1 {0 1 2 3 4 5 6} 
    2 {0 1 2 3}
  }
  
  for {set i 0} {$i<100} {incr i} {
    do_execsql_test 1.4.$i { INSERT INTO t1(t1) VALUES('merge=1,4') }
    do_test 1.4.$i.2 { fts3_integrity_check t1 } ok
    do_execsql_test 1.4.$i.3 { 
................................................................................
      SELECT docid FROM t1 WHERE t1 MATCH 'zero one two three'
    } {123 132 213 231 312 321}
  }
  
  do_execsql_test 1.5 { 
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level 
  } {
    2 {0 1}
    3 0
  }
  
  #-------------------------------------------------------------------------
  # Test cases 2.* test that errors in the xxx part of the 'merge=xxx' are
  # handled correctly.
  #
................................................................................
    3 {0 1 2 3 4 5 6}
  }
  
  do_execsql_test 3.3 { 
    INSERT INTO t2(t2) VALUES('merge=1000000,2');
    SELECT level, group_concat(idx, ' ') FROM t2_segdir GROUP BY level 
  } {
    0 0 
    2 0
    3 0 
    4 0
    6 0
  }
  
  #-------------------------------------------------------------------------
  # Test cases 4.*
  #
  reset_db
  do_execsql_test 4.1 "
................................................................................
  }
  
  do_execsql_test 5.3 {
    INSERT INTO t1(t1) VALUES('merge=1,5');
    INSERT INTO t1(t1) VALUES('merge=1,5');
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
  } {
    0 {0 1 2}
    1 {0 1 2 3 4 5 6 7 8 9 10 11 12 13 14} 
    2 {0 1 2 3}
  }
  
  do_execsql_test 5.4 {SELECT quote(value) from t1_stat WHERE rowid=1} {X'0105'}
  do_test 5.5 {
    foreach docid [execsql {SELECT docid FROM t1}] {
      execsql {INSERT INTO t1 SELECT * FROM t1 WHERE docid=$docid}
    }
  } {}
  
  do_execsql_test 5.6 {SELECT quote(value) from t1_stat WHERE rowid=1} {X'0105'}
  
  do_execsql_test 5.7 {
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
    SELECT quote(value) from t1_stat WHERE rowid=1;
  } {
    0 {0 1 2 3 4 5 6 7 8 9 10} 
    1 {0 1 2 3 4 5 6 7 8 9 10 11 12} 
    2 {0 1 2 3 4 5 6 7}
    X'0105'
  }
  
  do_execsql_test 5.8 {
    INSERT INTO t1(t1) VALUES('merge=1,6');
    INSERT INTO t1(t1) VALUES('merge=1,6');
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
    SELECT quote(value) from t1_stat WHERE rowid=1;
  } {
    0 {0 1 2 3 4} 
    1 {0 1 2 3 4 5 6 7 8 9 10 11 12 13} 
    2 {0 1 2 3 4 5 6 7 8} X'0106'
  }
  
  do_test 5.8.1 { fts3_integrity_check t1 } ok
  
  do_test 5.9 {
    set L [expr 16*16*7 + 16*3 + 12]
    foreach docid [execsql {
................................................................................
    }
  } {}
  
  do_execsql_test 5.10 {
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
    SELECT quote(value) from t1_stat WHERE rowid=1;
  } {
    0 0 1 {0 1} 2 0 3 0 X'0106'
  }
  
  do_execsql_test 5.11 {
    INSERT INTO t1(t1) VALUES('merge=1,6');
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
    SELECT quote(value) from t1_stat WHERE rowid=1;
  } {
    0 0 1 {0 1} 2 0 3 0 X''
  }
  
  #-------------------------------------------------------------------------
  # Test cases 6.*
  #
  # At one point the following test caused an assert() to fail (because the
  # second 'merge=1,2' operation below actually "merges" a single input

      SELECT docid FROM t1 WHERE t1 MATCH 'zero one two three'
    } {123 132 213 231 312 321}
  }
  
  do_execsql_test 1.3 { 
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level 
  } {


    2 {0 1 2 3}
  }
  
  for {set i 0} {$i<100} {incr i} {
    do_execsql_test 1.4.$i { INSERT INTO t1(t1) VALUES('merge=1,4') }
    do_test 1.4.$i.2 { fts3_integrity_check t1 } ok
    do_execsql_test 1.4.$i.3 { 
................................................................................
      SELECT docid FROM t1 WHERE t1 MATCH 'zero one two three'
    } {123 132 213 231 312 321}
  }
  
  do_execsql_test 1.5 { 
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level 
  } {

    3 0
  }
  
  #-------------------------------------------------------------------------
  # Test cases 2.* test that errors in the xxx part of the 'merge=xxx' are
  # handled correctly.
  #
................................................................................
    3 {0 1 2 3 4 5 6}
  }
  
  do_execsql_test 3.3 { 
    INSERT INTO t2(t2) VALUES('merge=1000000,2');
    SELECT level, group_concat(idx, ' ') FROM t2_segdir GROUP BY level 
  } {



    4 0

  }
  
  #-------------------------------------------------------------------------
  # Test cases 4.*
  #
  reset_db
  do_execsql_test 4.1 "
................................................................................
  }
  
  do_execsql_test 5.3 {
    INSERT INTO t1(t1) VALUES('merge=1,5');
    INSERT INTO t1(t1) VALUES('merge=1,5');
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
  } {

    1 {0 1 2 3 4 5 6 7 8 9 10 11 12 13 14} 
    2 {0 1 2 3}
  }
  
  do_execsql_test 5.4 {SELECT quote(value) from t1_stat WHERE rowid=1} {X'010F'}
  do_test 5.5 {
    foreach docid [execsql {SELECT docid FROM t1}] {
      execsql {INSERT INTO t1 SELECT * FROM t1 WHERE docid=$docid}
    }
  } {}
  
  do_execsql_test 5.6 {SELECT quote(value) from t1_stat WHERE rowid=1} {X'010F'}
  
  do_execsql_test 5.7 {
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
    SELECT quote(value) from t1_stat WHERE rowid=1;
  } {
    0 {0 1 2 3 4 5 6 7} 
    1 {0 1 2 3 4 5 6 7 8 9 10 11 12} 
    2 {0 1 2 3 4 5 6 7} 
    X'010F'
  }
  
  do_execsql_test 5.8 {
    INSERT INTO t1(t1) VALUES('merge=1,6');
    INSERT INTO t1(t1) VALUES('merge=1,6');
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
    SELECT quote(value) from t1_stat WHERE rowid=1;
  } {

    1 {0 1 2 3 4 5 6 7 8 9 10 11 12 13} 
    2 {0 1 2 3 4 5 6 7 8} X'010E'
  }
  
  do_test 5.8.1 { fts3_integrity_check t1 } ok
  
  do_test 5.9 {
    set L [expr 16*16*7 + 16*3 + 12]
    foreach docid [execsql {
................................................................................
    }
  } {}
  
  do_execsql_test 5.10 {
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
    SELECT quote(value) from t1_stat WHERE rowid=1;
  } {
    0 {0 1 2 3 4 5 6 7 8 9 10 11} 1 0 2 0 3 0 X'010E'
  }
  
  do_execsql_test 5.11 {
    INSERT INTO t1(t1) VALUES('merge=1,6');
    SELECT level, group_concat(idx, ' ') FROM t1_segdir GROUP BY level;
    SELECT quote(value) from t1_stat WHERE rowid=1;
  } {
    1 {0 1} 2 0 3 0 X'010E'
  }
  
  #-------------------------------------------------------------------------
  # Test cases 6.*
  #
  # At one point the following test caused an assert() to fail (because the
  # second 'merge=1,2' operation below actually "merges" a single input

      do_test 1.6.$i.2 { 
        sql2 "SELECT docid FROM t2 WHERE t2 MATCH 'abc'" 
      } {1485}
    }

    do_test 1.7 { sql2 { 
      SELECT level, count(*) FROM t2_segdir GROUP BY level ORDER BY 1
    } } [list  0 1  2 18  3 5]

    # Using the old connection, insert many rows. 
    do_test 1.8 {
      for {set i 0} {$i < 1500} {incr i} {
        sql2 "INSERT INTO t2 SELECT content FROM t2 WHERE docid = $i"
      }
    } {}

    do_test 1.9 { sql2 { 
      SELECT level, count(*) FROM t2_segdir GROUP BY level ORDER BY 1
    } } [list  0 13  1 13  2 5  3 6]

    # Run a big incr-merge operation on the db.
    do_test 1.10 { sql1 { INSERT INTO t2(t2) VALUES('merge=2000,2') } } {}
    do_test 1.11 { 
      sql2 "SELECT docid FROM t2 WHERE t2 MATCH 'abc'" 
    } {1485 21485}

................................................................................
    do_test 1.14 { 
      sql2 "INSERT INTO t2(t2) VALUES('optimize')"
      sql2 "SELECT docid FROM t2 WHERE t2 MATCH 'abc'" 
    } {1485 21485 22985}

    do_test 1.15 { sql2 { 
      SELECT level, count(*) FROM t2_segdir GROUP BY level ORDER BY 1
    } } {6 1}
  }
}


finish_test

      do_test 1.6.$i.2 { 
        sql2 "SELECT docid FROM t2 WHERE t2 MATCH 'abc'" 
      } {1485}
    }

    do_test 1.7 { sql2 { 
      SELECT level, count(*) FROM t2_segdir GROUP BY level ORDER BY 1
    } } {2 15 3 5}

    # Using the old connection, insert many rows. 
    do_test 1.8 {
      for {set i 0} {$i < 1500} {incr i} {
        sql2 "INSERT INTO t2 SELECT content FROM t2 WHERE docid = $i"
      }
    } {}

    do_test 1.9 { sql2 { 
      SELECT level, count(*) FROM t2_segdir GROUP BY level ORDER BY 1
    } } [list  0 12  1 13  2 4  3 6]

    # Run a big incr-merge operation on the db.
    do_test 1.10 { sql1 { INSERT INTO t2(t2) VALUES('merge=2000,2') } } {}
    do_test 1.11 { 
      sql2 "SELECT docid FROM t2 WHERE t2 MATCH 'abc'" 
    } {1485 21485}

................................................................................
    do_test 1.14 { 
      sql2 "INSERT INTO t2(t2) VALUES('optimize')"
      sql2 "SELECT docid FROM t2 WHERE t2 MATCH 'abc'" 
    } {1485 21485 22985}

    do_test 1.15 { sql2 { 
      SELECT level, count(*) FROM t2_segdir GROUP BY level ORDER BY 1
    } } {4 1}
  }
}


finish_test

  2080 33 
  3104 33
}

do_test 1.6 {
  while 1 {
    set tc1 [db total_changes]
    execsql { INSERT INTO t2(t2) VALUES('merge=5,0') }
    set tc2 [db total_changes]
    if {($tc2 - $tc1) < 2} break
  }
  execsql { SELECT level, count(*) FROM t2_segdir GROUP BY level }
} {33 1 1057 1 2081 1 3105 1}
do_execsql_test 1.7 { INSERT INTO t2(t2) VALUES('integrity-check') }

................................................................................
  2080 37 
  3104 37
}

do_test 2.6 {
  while 1 {
    set tc1 [db total_changes]
    execsql { INSERT INTO t2(t2) VALUES('merge=5,0') }
    set tc2 [db total_changes]
    if {($tc2 - $tc1) < 2} break
  }
  execsql { SELECT level, count(*) FROM t2_segdir GROUP BY level }
} {33 1 1057 1 2081 1 3105 1}
do_execsql_test 2.7 { INSERT INTO t2(t2) VALUES('integrity-check') }

do_execsql_test 2.8 {
  INSERT INTO t2(words) SELECT words FROM t1;
  SELECT level, count(*) FROM t2_segdir GROUP BY level;
} {0 2 1024 2 2048 2 3072 2}

finish_test

  2080 33 
  3104 33
}

do_test 1.6 {
  while 1 {
    set tc1 [db total_changes]
    execsql { INSERT INTO t2(t2) VALUES('merge=5,2') }
    set tc2 [db total_changes]
    if {($tc2 - $tc1) < 2} break
  }
  execsql { SELECT level, count(*) FROM t2_segdir GROUP BY level }
} {33 1 1057 1 2081 1 3105 1}
do_execsql_test 1.7 { INSERT INTO t2(t2) VALUES('integrity-check') }

................................................................................
  2080 37 
  3104 37
}

do_test 2.6 {
  while 1 {
    set tc1 [db total_changes]
    execsql { INSERT INTO t2(t2) VALUES('merge=5,2') }
    set tc2 [db total_changes]
    if {($tc2 - $tc1) < 2} break
  }
  execsql { SELECT level, count(*) FROM t2_segdir GROUP BY level }
} {33 1 1057 1 2081 1 3105 1}
do_execsql_test 2.7 { INSERT INTO t2(t2) VALUES('integrity-check') }

do_execsql_test 2.8 {
  INSERT INTO t2(words) SELECT words FROM t1;
  SELECT level, count(*) FROM t2_segdir GROUP BY level;
} {0 2 1024 2 2048 2 3072 2}

finish_test

do_multiclient_test tn {
  do_test unixexcl-3.$tn.1 {
    code1 { db close; sqlite3 db file:test.db?psow=0 -vfs unix-excl -uri 1 }
    code2 { db2 close; sqlite3 db2 file:test.db?psow=0 -vfs unix-excl -uri 1 }
    sql1 {
      PRAGMA auto_vacuum = 0;
      PRAGMA journal_mode = WAL;

      CREATE TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
    }
  } {wal}

  if {$tn==1} {
    do_test unixexcl-3.$tn.1.multiproc {

do_multiclient_test tn {
  do_test unixexcl-3.$tn.1 {
    code1 { db close; sqlite3 db file:test.db?psow=0 -vfs unix-excl -uri 1 }
    code2 { db2 close; sqlite3 db2 file:test.db?psow=0 -vfs unix-excl -uri 1 }
    sql1 {
      PRAGMA auto_vacuum = 0;
      PRAGMA journal_mode = WAL;
      PRAGMA synchronous = FULL;
      CREATE TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
    }
  } {wal}

  if {$tn==1} {
    do_test unixexcl-3.$tn.1.multiproc {

    catch { db close }
  }
}

#-------------------------------------------------------------------------
# Test that "PRAGMA checkpoint_fullsync" appears to be working.
#
foreach {tn sql reslist altreslist} {
  1 { }                                 {10 0 4 0 6 0} {7 4 3 2 3 2}
  2 { PRAGMA checkpoint_fullfsync = 1 } {10 4 4 2 6 2} {7 4 3 2 3 2}
  3 { PRAGMA checkpoint_fullfsync = 0 } {10 0 4 0 6 0} {7 0 3 0 3 0}
} {
  faultsim_delete_and_reopen

  execsql {PRAGMA auto_vacuum = 0}
  execsql $sql
  do_execsql_test wal2-14.$tn.0 { PRAGMA page_size = 4096 }   {}
  do_execsql_test wal2-14.$tn.1 { PRAGMA journal_mode = WAL } {wal}

  set sqlite_sync_count 0
  set sqlite_fullsync_count 0

  set useres $reslist
  if $::sqlite_options(default_wal_safetylevel) {
    set useres $altreslist
  }

  do_execsql_test wal2-14.$tn.2 {
    PRAGMA wal_autocheckpoint = 10;
    CREATE TABLE t1(a, b);                -- 2 wal syncs
    INSERT INTO t1 VALUES(1, 2);          -- 2 wal sync
    PRAGMA wal_checkpoint;                -- 1 wal sync, 1 db sync
    BEGIN;

    catch { db close }
  }
}

#-------------------------------------------------------------------------
# Test that "PRAGMA checkpoint_fullsync" appears to be working.
#
foreach {tn sql reslist} {
  1 { }                                 {10 0 4 0 6 0}
  2 { PRAGMA checkpoint_fullfsync = 1 } {10 4 4 2 6 2}
  3 { PRAGMA checkpoint_fullfsync = 0 } {10 0 4 0 6 0}
} {
  faultsim_delete_and_reopen

  execsql {PRAGMA auto_vacuum = 0; PRAGMA synchronous = FULL;}
  execsql $sql
  do_execsql_test wal2-14.$tn.0 { PRAGMA page_size = 4096 }   {}
  do_execsql_test wal2-14.$tn.1 { PRAGMA journal_mode = WAL } {wal}

  set sqlite_sync_count 0
  set sqlite_fullsync_count 0

  set useres $reslist




  do_execsql_test wal2-14.$tn.2 {
    PRAGMA wal_autocheckpoint = 10;
    CREATE TABLE t1(a, b);                -- 2 wal syncs
    INSERT INTO t1 VALUES(1, 2);          -- 2 wal sync
    PRAGMA wal_checkpoint;                -- 1 wal sync, 1 db sync
    BEGIN;

#   CREATE TABLE x(y);
#   INSERT INTO x VALUES('z');
#   PRAGMA wal_checkpoint;
#
# in WAL mode the xSync method is invoked as expected for each of
# synchronous=off, synchronous=normal and synchronous=full.
#
foreach {tn syncmode synccount altsynccount} {
  1 off     
    {}
    {}
  2 normal  
    {test.db-wal normal test.db normal}
    {test.db-wal full test.db full}
  3 full    
    {test.db-wal normal test.db-wal normal test.db-wal normal test.db normal}
    {test.db-wal normal test.db-wal normal test.db-wal full test.db full}
} {

  proc sync_counter {args} { 
    foreach {method filename id flags} $args break
    lappend ::syncs [file tail $filename] $flags
  }
  set usecount $synccount
  if $::sqlite_options(default_wal_safetylevel) {
    set usecount $altsynccount
  }

  do_test wal3-3.$tn {
    forcedelete test.db test.db-wal test.db-journal
  
    testvfs T
    T filter {} 
    T script sync_counter

#   CREATE TABLE x(y);
#   INSERT INTO x VALUES('z');
#   PRAGMA wal_checkpoint;
#
# in WAL mode the xSync method is invoked as expected for each of
# synchronous=off, synchronous=normal and synchronous=full.
#
foreach {tn syncmode synccount} {
  1 off     

    {}
  2 normal  
    {test.db-wal normal test.db normal}

  3 full    
    {test.db-wal normal test.db-wal normal test.db-wal normal test.db normal}

} {

  proc sync_counter {args} { 
    foreach {method filename id flags} $args break
    lappend ::syncs [file tail $filename] $flags
  }
  set usecount $synccount




  do_test wal3-3.$tn {
    forcedelete test.db test.db-wal test.db-journal
  
    testvfs T
    T filter {} 
    T script sync_counter

  # Repeat the previous with POWERSAFE_OVERWRITE off.  Verify that the WAL file
  # is padded.
  #
  do_test zerodamage-3.1 {
    db close
    sqlite3 db file:test.db?psow=FALSE -uri 1
    db eval {

       UPDATE t1 SET y=randomblob(50) WHERE x=124;
    }
    file size test.db-wal
  } {16800}
}

finish_test

  # Repeat the previous with POWERSAFE_OVERWRITE off.  Verify that the WAL file
  # is padded.
  #
  do_test zerodamage-3.1 {
    db close
    sqlite3 db file:test.db?psow=FALSE -uri 1
    db eval {
       PRAGMA synchronous=FULL;
       UPDATE t1 SET y=randomblob(50) WHERE x=124;
    }
    file size test.db-wal
  } {16800}
}

finish_test