SQLite

/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.334 2007/01/27 02:24:55 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

*/
typedef struct IntegrityCk IntegrityCk;
struct IntegrityCk {
  BtShared *pBt;    /* The tree being checked out */
  Pager *pPager; /* The associated pager.  Also accessible by pBt->pPager */
  int nPage;     /* Number of pages in the database */
  int *anRef;    /* Number of times each page is referenced */
  int mxErr;        /* Stop accumulating errors when this reaches zero */
  char *zErrMsg;    /* An error message.  NULL if no errors seen. */
  int nErr;         /* Number of messages written to zErrMsg so far */
};

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/*
** Append a message to the error message string.
*/
static void checkAppendMsg(
  IntegrityCk *pCheck,
  char *zMsg1,
  const char *zFormat,
  ...
){
  va_list ap;
  char *zMsg2;
  if( !pCheck->mxErr ) return;
  pCheck->mxErr--;
  pCheck->nErr++;
  va_start(ap, zFormat);
  zMsg2 = sqlite3VMPrintf(zFormat, ap);
  va_end(ap);
  if( zMsg1==0 ) zMsg1 = "";
  if( pCheck->zErrMsg ){
    char *zOld = pCheck->zErrMsg;
    pCheck->zErrMsg = 0;

  int iPage,            /* Page number for first page in the list */
  int N,                /* Expected number of pages in the list */
  char *zContext        /* Context for error messages */
){
  int i;
  int expected = N;
  int iFirst = iPage;
  while( N-- > 0 && pCheck->mxErr ){
    unsigned char *pOvfl;
    if( iPage<1 ){
      checkAppendMsg(pCheck, zContext,
         "%d of %d pages missing from overflow list starting at %d",
          N+1, expected, iFirst);
      break;
    }

    releasePage(pPage);
    return 0;
  }

  /* Check out all the cells.
  */
  depth = 0;
  for(i=0; i<pPage->nCell && pCheck->mxErr; i++){
    u8 *pCell;
    int sz;
    CellInfo info;

    /* Check payload overflow pages
    */
    sprintf(zContext, "On tree page %d cell %d: ", iPage, i);

** a table.  nRoot is the number of entries in aRoot.
**
** If everything checks out, this routine returns NULL.  If something is
** amiss, an error message is written into memory obtained from malloc()
** and a pointer to that error message is returned.  The calling function
** is responsible for freeing the error message when it is done.
*/
char *sqlite3BtreeIntegrityCheck(
  Btree *p,     /* The btree to be checked */
  int *aRoot,   /* An array of root pages numbers for individual trees */
  int nRoot,    /* Number of entries in aRoot[] */
  int mxErr,    /* Stop reporting errors after this many */
  int *pnErr    /* Write number of errors seen to this variable */
){
  int i;
  int nRef;
  IntegrityCk sCheck;
  BtShared *pBt = p->pBt;

  nRef = sqlite3pager_refcount(pBt->pPager);
  if( lockBtreeWithRetry(p)!=SQLITE_OK ){
    return sqliteStrDup("Unable to acquire a read lock on the database");
  }
  sCheck.pBt = pBt;
  sCheck.pPager = pBt->pPager;
  sCheck.nPage = sqlite3pager_pagecount(sCheck.pPager);
  sCheck.mxErr = mxErr;
  sCheck.nErr = 0;
  *pnErr = 0;
  if( sCheck.nPage==0 ){
    unlockBtreeIfUnused(pBt);
    return 0;
  }
  sCheck.anRef = sqliteMallocRaw( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
  if( !sCheck.anRef ){
    unlockBtreeIfUnused(pBt);
    *pnErr = 1;
    return sqlite3MPrintf("Unable to malloc %d bytes", 
        (sCheck.nPage+1)*sizeof(sCheck.anRef[0]));
  }
  for(i=0; i<=sCheck.nPage; i++){ sCheck.anRef[i] = 0; }
  i = PENDING_BYTE_PAGE(pBt);
  if( i<=sCheck.nPage ){
    sCheck.anRef[i] = 1;
  }
  sCheck.zErrMsg = 0;

  /* Check the integrity of the freelist
  */
  checkList(&sCheck, 1, get4byte(&pBt->pPage1->aData[32]),
            get4byte(&pBt->pPage1->aData[36]), "Main freelist: ");

  /* Check all the tables.
  */
  for(i=0; i<nRoot && sCheck.mxErr; i++){
    if( aRoot[i]==0 ) continue;
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum && aRoot[i]>1 ){
      checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0, 0);
    }
#endif
    checkTreePage(&sCheck, aRoot[i], 0, "List of tree roots: ");
  }

  /* Make sure every page in the file is referenced
  */
  for(i=1; i<=sCheck.nPage && sCheck.mxErr; i++){
#ifdef SQLITE_OMIT_AUTOVACUUM
    if( sCheck.anRef[i]==0 ){
      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
    }
#else
    /* If the database supports auto-vacuum, make sure no tables contain
    ** references to pointer-map pages.

      nRef, sqlite3pager_refcount(pBt->pPager)
    );
  }

  /* Clean  up and report errors.
  */
  sqliteFree(sCheck.anRef);
  *pnErr = sCheck.nErr;
  return sCheck.zErrMsg;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

/*
** Return the full pathname of the underlying database file.
*/

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.72 2007/01/27 02:24:55 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/

int sqlite3BtreeKeySize(BtCursor*, i64 *pSize);
int sqlite3BtreeKey(BtCursor*, u32 offset, u32 amt, void*);
const void *sqlite3BtreeKeyFetch(BtCursor*, int *pAmt);
const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);

char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
struct Pager *sqlite3BtreePager(Btree*);


#ifdef SQLITE_TEST
int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
void sqlite3BtreeCursorList(Btree*);
#endif

/*
** 2003 April 6
**
** 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 code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.127 2007/01/27 02:24:56 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/

  ** used will be case sensitive or not depending on the RHS.
  */
  if( sqlite3StrICmp(zLeft, "case_sensitive_like")==0 ){
    if( zRight ){
      sqlite3RegisterLikeFunctions(db, getBoolean(zRight));
    }
  }else

#ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
# define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
#endif

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
  if( sqlite3StrICmp(zLeft, "integrity_check")==0 ){
    int i, j, addr, mxErr;

    /* Code that appears at the end of the integrity check.  If no error
    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static const VdbeOpList endCode[] = {
      { OP_MemLoad,     0, 0,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Ne,          0, 0,        0},    /* 2 */
      { OP_String8,     0, 0,        "ok"},
      { OP_Callback,    1, 0,        0},
    };

    /* Initialize the VDBE program */
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", P3_STATIC);

    /* Set the maximum error count */
    mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
    if( zRight ){
      mxErr = atoi(zRight);
      if( mxErr<=0 ){
        mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
      }
    }
    sqlite3VdbeAddOp(v, OP_MemInt, mxErr, 0);

    /* Do an integrity check on each database file */
    for(i=0; i<db->nDb; i++){
      HashElem *x;
      Hash *pTbls;
      int cnt = 0;

      if( OMIT_TEMPDB && i==1 ) continue;

      sqlite3CodeVerifySchema(pParse, i);
      addr = sqlite3VdbeAddOp(v, OP_IfMemPos, 0, 0);
      sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
      sqlite3VdbeJumpHere(v, addr);

      /* Do an integrity check of the B-Tree
      */
      pTbls = &db->aDb[i].pSchema->tblHash;
      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        sqlite3VdbeAddOp(v, OP_Integer, pTab->tnum, 0);
        cnt++;
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          sqlite3VdbeAddOp(v, OP_Integer, pIdx->tnum, 0);
          cnt++;
        }
      }
      if( cnt==0 ) continue;
      sqlite3VdbeAddOp(v, OP_IntegrityCk, 0, i);
      addr = sqlite3VdbeAddOp(v, OP_IsNull, -1, 0);


      sqlite3VdbeOp3(v, OP_String8, 0, 0,
         sqlite3MPrintf("*** in database %s ***\n", db->aDb[i].zName),
         P3_DYNAMIC);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp(v, OP_Concat, 0, 0);
      sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
      sqlite3VdbeJumpHere(v, addr);

      /* Make sure all the indices are constructed correctly.
      */

      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        int loopTop;

        if( pTab->pIndex==0 ) continue;
        addr = sqlite3VdbeAddOp(v, OP_IfMemPos, 0, 0);
        sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
        sqlite3VdbeJumpHere(v, addr);
        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
        sqlite3VdbeAddOp(v, OP_MemInt, 0, 1);
        loopTop = sqlite3VdbeAddOp(v, OP_Rewind, 1, 0);
        sqlite3VdbeAddOp(v, OP_MemIncr, 1, 1);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          int jmp2;
          static const VdbeOpList idxErr[] = {
            { OP_MemIncr,    -1,  0,  0},
            { OP_String8,     0,  0,  "rowid "},
            { OP_Rowid,       1,  0,  0},
            { OP_String8,     0,  0,  " missing from index "},
            { OP_String8,     0,  0,  0},    /* 4 */
            { OP_Concat,      2,  0,  0},
            { OP_Callback,    1,  0,  0},
          };

             { OP_MemInt,       0,  2,  0},
             { OP_Rewind,       0,  0,  0},  /* 1 */
             { OP_MemIncr,      1,  2,  0},
             { OP_Next,         0,  0,  0},  /* 3 */
             { OP_MemLoad,      1,  0,  0},
             { OP_MemLoad,      2,  0,  0},
             { OP_Eq,           0,  0,  0},  /* 6 */
             { OP_MemIncr,     -1,  0,  0},
             { OP_String8,      0,  0,  "wrong # of entries in index "},
             { OP_String8,      0,  0,  0},  /* 9 */
             { OP_Concat,       0,  0,  0},
             { OP_Callback,     1,  0,  0},
          };
          if( pIdx->tnum==0 ) continue;
          addr = sqlite3VdbeAddOp(v, OP_IfMemPos, 0, 0);
          sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
          sqlite3VdbeJumpHere(v, addr);
          addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
          sqlite3VdbeChangeP1(v, addr+1, j+2);
          sqlite3VdbeChangeP2(v, addr+1, addr+4);
          sqlite3VdbeChangeP1(v, addr+3, j+2);
          sqlite3VdbeChangeP2(v, addr+3, addr+2);
          sqlite3VdbeJumpHere(v, addr+6);
          sqlite3VdbeChangeP3(v, addr+9, pIdx->zName, P3_STATIC);
        }
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
    sqlite3VdbeChangeP1(v, addr+1, mxErr);
    sqlite3VdbeJumpHere(v, addr+2);
  }else
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test3.c,v 1.69 2007/01/27 02:24:56 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "btree.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

  int argc,              /* Number of arguments */
  const char **argv      /* Text of each argument */
){
  Btree *pBt;
  int nRoot;
  int *aRoot;
  int i;
  int nErr;
  char *zResult;

  if( argc<3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID ROOT ...\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  nRoot = argc-2;
  aRoot = malloc( sizeof(int)*(argc-2) );
  for(i=0; i<argc-2; i++){
    if( Tcl_GetInt(interp, argv[i+2], &aRoot[i]) ) return TCL_ERROR;
  }
#ifndef SQLITE_OMIT_INTEGRITY_CHECK
  zResult = sqlite3BtreeIntegrityCheck(pBt, aRoot, nRoot, 10000, &nErr);
#else
  zResult = 0;
#endif
  free(aRoot);
  if( zResult ){
    Tcl_AppendResult(interp, zResult, 0);
    sqliteFree(zResult); 

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.587 2007/01/27 02:24:56 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

case OP_DropTrigger: {        /* no-push */
  sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p3);
  break;
}


#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/* Opcode: IntegrityCk P1 P2 *
**
** Do an analysis of the currently open database.  Push onto the
** stack the text of an error message describing any problems.
** If no problems are found, push a NULL onto the stack.
**
** P1 is the address of a memory cell that contains the maximum
** number of allowed errors.  At most mem[P1] errors will be reported.
** In other words, the analysis stops as soon as mem[P1] errors are 
** seen.  Mem[P1] is updated with the number of errors remaining.
**
** The root page numbers of all tables in the database are integer
** values on the stack.  This opcode pulls as many integers as it
** can off of the stack and uses those numbers as the root pages.
**
** If P2 is not zero, the check is done on the auxiliary database
** file, not the main database file.
**
** This opcode is used to implement the integrity_check pragma.
*/
case OP_IntegrityCk: {
  int nRoot;
  int *aRoot;
  int j;
  int nErr;
  char *z;
  Mem *pnErr;

  for(nRoot=0; &pTos[-nRoot]>=p->aStack; nRoot++){
    if( (pTos[-nRoot].flags & MEM_Int)==0 ) break;
  }
  assert( nRoot>0 );
  aRoot = sqliteMallocRaw( sizeof(int*)*(nRoot+1) );
  if( aRoot==0 ) goto no_mem;
  j = pOp->p1;
  assert( j>=0 && j<p->nMem );
  pnErr = &p->aMem[j];
  assert( (pnErr->flags & MEM_Int)!=0 );
  for(j=0; j<nRoot; j++){
    Mem *pMem = &pTos[-j];
    aRoot[j] = pMem->i;
  }
  aRoot[j] = 0;
  popStack(&pTos, nRoot);
  pTos++;
  z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p2].pBt, aRoot, nRoot,
                                 pnErr->i, &nErr);
  pnErr->i -= nErr;
  if( nErr==0 ){
    assert( z==0 );


    pTos->flags = MEM_Null;
  }else{
    pTos->z = z;
    pTos->n = strlen(z);
    pTos->flags = MEM_Str | MEM_Dyn | MEM_Term;
    pTos->xDel = 0;
  }
  pTos->enc = SQLITE_UTF8;

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests for the PRAGMA command.
#
# $Id: pragma.test,v 1.48 2007/01/27 02:24:56 drh Exp $

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

# Test organization:
#
# pragma-1.*: Test cache_size, default_cache_size and synchronous on main db.

    set c [btree_cursor $db $rootpage 1]
    btree_first $c
    btree_delete $c
    btree_commit $db
    btree_close $db
    execsql {PRAGMA integrity_check}
  } {{rowid 1 missing from index i2} {wrong # of entries in index i2}}
  do_test pragma-3.3 {
    execsql {PRAGMA integrity_check=1}
  } {{rowid 1 missing from index i2}}
  do_test pragma-3.4 {
    execsql {
      ATTACH DATABASE 'test.db' AS t2;
      PRAGMA integrity_check
}
  } {{rowid 1 missing from index i2} {wrong # of entries in index i2} {rowid 1 missing from index i2} {wrong # of entries in index i2}}
  do_test pragma-3.5 {
  execsql {
      PRAGMA integrity_check=3
    }
  } {{rowid 1 missing from index i2} {wrong # of entries in index i2} {rowid 1 missing from index i2}}
  do_test pragma-3.6 {
    execsql {
      PRAGMA integrity_check=xyz
    }
  } {{rowid 1 missing from index i2} {wrong # of entries in index i2} {rowid 1 missing from index i2} {wrong # of entries in index i2}}
  do_test pragma-3.7 {
    execsql {
      PRAGMA integrity_check=0
    }
  } {{rowid 1 missing from index i2} {wrong # of entries in index i2} {rowid 1 missing from index i2} {wrong # of entries in index i2}}

  # Add additional corruption by appending unused pages to the end of
  # the database file testerr.db
  #
  do_test pragma-3.8 {
    execsql {DETACH t2}
    file delete -force testerr.db testerr.db-journal
    set out [open testerr.db wb]
    set in [open test.db rb]
    puts -nonewline $out [read $in]
    seek $in 0
    puts -nonewline $out [read $in]
    close $in
    close $out
    execsql {REINDEX t2}
    execsql {PRAGMA integrity_check}
  } {ok}
  do_test pragma-3.9 {
    execsql {
      ATTACH 'testerr.db' AS t2;
      PRAGMA integrity_check
  } 
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2} {wrong # of entries in index i2}}
  do_test pragma-3.10 {
    execsql {
      PRAGMA integrity_check=1
    }
  } {{*** in database t2 ***
Page 4 is never used}}
  do_test pragma-3.11 {
    execsql {
      PRAGMA integrity_check=5
    }
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2} {wrong # of entries in index i2}}
  do_test pragma-3.12 {
    execsql {
      PRAGMA integrity_check=4
    }
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2}}
  do_test pragma-3.13 {
    execsql {
      PRAGMA integrity_check=3
    }
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used}}
  do_test pragma-3.14 {
    execsql {
      PRAGMA integrity_check(2)
    }
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used}}
  do_test pragma-3.15 {
    execsql {
      ATTACH 'testerr.db' AS t3;
      PRAGMA integrity_check
    }
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2} {wrong # of entries in index i2} {*** in database t3 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2} {wrong # of entries in index i2}}
  do_test pragma-3.16 {
    execsql {
      PRAGMA integrity_check(9)
    }
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2} {wrong # of entries in index i2} {*** in database t3 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2}}
  do_test pragma-3.17 {
    execsql {
      PRAGMA integrity_check=7
    }
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2} {wrong # of entries in index i2} {*** in database t3 ***
Page 4 is never used
Page 5 is never used}}
  do_test pragma-3.18 {
    execsql {
      PRAGMA integrity_check=4
    }
  } {{*** in database t2 ***
Page 4 is never used
Page 5 is never used
Page 6 is never used} {rowid 1 missing from index i2}}
}
do_test pragma-3.99 {
  file delete -force testerr.db testerr.db-journal
  catchsql {DETACH t3}
  catchsql {DETACH t2}
  catchsql {DROP INDEX i2}
} {0 {}}

# Test modifying the cache_size of an attached database.
ifcapable pager_pragmas {
do_test pragma-4.1 {
  execsql {
    pragma aux.cache_size;
    pragma aux.default_cache_size;

#
# Run this Tcl script to generate the pragma.html file.
#
set rcsid {$Id: pragma.tcl,v 1.19 2007/01/27 02:24:57 drh Exp $}
source common.tcl
header {Pragma statements supported by SQLite}

proc Section {name {label {}}} {
  puts "\n<hr />"
  if {$label!=""} {
    puts "<a name=\"$label\"></a>"

}

Section {Pragmas to debug the library} debug

puts {
<ul>
<a name="pragma_integrity_check"></a>
<li><p><b>PRAGMA integrity_check;
    <br>PRAGMA integrity_check(</b><i>integer</i><b>)</b></p>
    <p>The command does an integrity check of the entire database.  It
    looks for out-of-order records, missing pages, malformed records, and
    corrupt indices.
    If any problems are found, then strings are returned (as multiple
    rows with a single column per row) which describe
    the problems.  At most <i>integer</i> errors will be reported
    before the analysis quits.  The default value for <i>integer</i>
    is 100.  If no errors are found, a single row with the value "ok" is
    returned.</p></li>

<a name="pragma_parser_trace"></a>
<li><p><b>PRAGMA parser_trace = ON; </b>(1)<b>
    <br>PRAGMA parser_trace = OFF;</b> (0)</p>
    <p>Turn tracing of the SQL parser inside of the
    SQLite library on and off.  This is used for debugging.