SQLite

      v = v*10 + c - '0';
      z++;
    }
    if( i==0 ) pTable->nRowEst = v;
    if( pIndex==0 ) break;
    pIndex->aiRowEst[i] = v;
    if( *z==' ' ) z++;
    if( memcmp(z, "unordered", 10)==0 ){
      pIndex->bUnordered = 1;
      break;
    }
  }
  return 0;
}

/*
** If the Index.aSample variable is not NULL, delete the aSample[] array
** and its contents.

        zKey = (char *)sqlite3_value_blob(argv[2]);
        rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
        break;

      case SQLITE_NULL:
        /* No key specified.  Use the key from the main database */
        sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
        if( nKey>0 || sqlite3BtreeGetReserve(db->aDb[0].pBt)>0 ){
          rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
        }
        break;
    }
  }
#endif

  /* If the file was opened successfully, read the schema for the new database.
  ** If this fails, or if opening the file failed, then close the file and 

*/
static int backupOnePage(sqlite3_backup *p, Pgno iSrcPg, const u8 *zSrcData){
  Pager * const pDestPager = sqlite3BtreePager(p->pDest);
  const int nSrcPgsz = sqlite3BtreeGetPageSize(p->pSrc);
  int nDestPgsz = sqlite3BtreeGetPageSize(p->pDest);
  const int nCopy = MIN(nSrcPgsz, nDestPgsz);
  const i64 iEnd = (i64)iSrcPg*(i64)nSrcPgsz;
#ifdef SQLITE_HAS_CODEC
  int nSrcReserve = sqlite3BtreeGetReserve(p->pSrc);
  int nDestReserve = sqlite3BtreeGetReserve(p->pDest);
#endif

  int rc = SQLITE_OK;
  i64 iOff;

  assert( p->bDestLocked );
  assert( !isFatalError(p->rc) );
  assert( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) );
  assert( zSrcData );

  /* Catch the case where the destination is an in-memory database and the
  ** page sizes of the source and destination differ. 
  */
  if( nSrcPgsz!=nDestPgsz && sqlite3PagerIsMemdb(pDestPager) ){
    rc = SQLITE_READONLY;
  }

#ifdef SQLITE_HAS_CODEC
  /* Backup is not possible if the page size of the destination is changing
  ** and a codec is in use.
  */
  if( nSrcPgsz!=nDestPgsz && sqlite3PagerGetCodec(pDestPager)!=0 ){
    rc = SQLITE_READONLY;
  }

  /* Backup is not possible if the number of bytes of reserve space differ
  ** between source and destination.  If there is a difference, try to
  ** fix the destination to agree with the source.  If that is not possible,
  ** then the backup cannot proceed.
  */
  if( nSrcReserve!=nDestReserve ){
    u32 newPgsz = nSrcPgsz;
    rc = sqlite3PagerSetPagesize(pDestPager, &newPgsz, nSrcReserve);
    if( rc==SQLITE_OK && newPgsz!=nSrcPgsz ) rc = SQLITE_READONLY;
  }
#endif

  /* This loop runs once for each destination page spanned by the source 
  ** page. For each iteration, variable iOff is set to the byte offset
  ** of the destination page.
  */
  for(iOff=iEnd-(i64)nSrcPgsz; rc==SQLITE_OK && iOff<iEnd; iOff+=nDestPgsz){

  for(p=pBackup; p; p=p->pNext){
    assert( sqlite3_mutex_held(p->pSrc->pBt->mutex) );
    if( !isFatalError(p->rc) && iPage<p->iNext ){
      /* The backup process p has already copied page iPage. But now it
      ** has been modified by a transaction on the source pager. Copy
      ** the new data into the backup.
      */
      int rc;
      assert( p->pDestDb );
      sqlite3_mutex_enter(p->pDestDb->mutex);
      rc = backupOnePage(p, iPage, aData);
      sqlite3_mutex_leave(p->pDestDb->mutex);
      assert( rc!=SQLITE_BUSY && rc!=SQLITE_LOCKED );
      if( rc!=SQLITE_OK ){
        p->rc = rc;
      }
    }
  }
}

        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
      }
      if( rc ){
        pTrunk = 0;
        goto end_allocate_page;
      }

      k = get4byte(&pTrunk->aData[4]); /* # of leaves on this trunk page */
      if( k==0 && !searchList ){
        /* The trunk has no leaves and the list is not being searched. 
        ** So extract the trunk page itself and use it as the newly 
        ** allocated page */
        assert( pPrevTrunk==0 );
        rc = sqlite3PagerWrite(pTrunk->pDbPage);
        if( rc ){

        TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));
#endif
      }else if( k>0 ){
        /* Extract a leaf from the trunk */
        u32 closest;
        Pgno iPage;
        unsigned char *aData = pTrunk->aData;




        if( nearby>0 ){
          u32 i;
          int dist;
          closest = 0;
          dist = sqlite3AbsInt32(get4byte(&aData[8]) - nearby);
          for(i=1; i<k; i++){
            int d2 = sqlite3AbsInt32(get4byte(&aData[8+i*4]) - nearby);

        testcase( iPage==mxPage );
        if( !searchList || iPage==nearby ){
          int noContent;
          *pPgno = iPage;
          TRACE(("ALLOCATE: %d was leaf %d of %d on trunk %d"
                 ": %d more free pages\n",
                 *pPgno, closest+1, k, pTrunk->pgno, n-1));
          rc = sqlite3PagerWrite(pTrunk->pDbPage);
          if( rc ) goto end_allocate_page;
          if( closest<k-1 ){
            memcpy(&aData[8+closest*4], &aData[4+k*4], 4);
          }
          put4byte(&aData[4], k-1);

          noContent = !btreeGetHasContent(pBt, *pPgno);
          rc = btreeGetPage(pBt, *pPgno, ppPage, noContent);
          if( rc==SQLITE_OK ){
            rc = sqlite3PagerWrite((*ppPage)->pDbPage);
            if( rc!=SQLITE_OK ){
              releasePage(*ppPage);
            }

      releasePage(*ppPage);
      return SQLITE_CORRUPT_BKPT;
    }
    (*ppPage)->isInit = 0;
  }else{
    *ppPage = 0;
  }
  assert( rc!=SQLITE_OK || sqlite3PagerIswriteable((*ppPage)->pDbPage) );
  return rc;
}

/*
** This function is used to add page iPage to the database file free-list. 
** It is assumed that the page is not already a part of the free-list.
**

    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
      goto begin_table_error;
    }
    pTable = sqlite3FindTable(db, zName, zDb);
    if( pTable ){
      if( !noErr ){
        sqlite3ErrorMsg(pParse, "table %T already exists", pName);
      }else{
        assert( !db->init.busy );
        sqlite3CodeVerifySchema(pParse, iDb);
      }
      goto begin_table_error;
    }
    if( sqlite3FindIndex(db, zName, zDb)!=0 ){
      sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);
      goto begin_table_error;
    }

  assert( pName->nSrc==1 );
  if( noErr ) db->suppressErr++;
  pTab = sqlite3LocateTable(pParse, isView, 
                            pName->a[0].zName, pName->a[0].zDatabase);
  if( noErr ) db->suppressErr--;

  if( pTab==0 ){
    if( noErr ) sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase);
    goto exit_drop_table;
  }
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb>=0 && iDb<db->nDb );

  /* If pTab is a virtual table, call ViewGetColumnNames() to ensure
  ** it is initialized.

        sqlite3ErrorMsg(pParse, "there is already a table named %s", zName);
        goto exit_create_index;
      }
    }
    if( sqlite3FindIndex(db, zName, pDb->zName)!=0 ){
      if( !ifNotExist ){
        sqlite3ErrorMsg(pParse, "index %s already exists", zName);
      }else{
        assert( !db->init.busy );
        sqlite3CodeVerifySchema(pParse, iDb);
      }
      goto exit_create_index;
    }
  }else{
    int n;
    Index *pLoop;
    for(pLoop=pTab->pIndex, n=1; pLoop; pLoop=pLoop->pNext, n++){}

  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    goto exit_drop_index;
  }
  pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);
  if( pIndex==0 ){
    if( !ifExists ){
      sqlite3ErrorMsg(pParse, "no such index: %S", pName, 0);
    }else{
      sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase);
    }
    pParse->checkSchema = 1;
    goto exit_drop_index;
  }
  if( pIndex->autoIndex ){
    sqlite3ErrorMsg(pParse, "index associated with UNIQUE "
      "or PRIMARY KEY constraint cannot be dropped", 0);

      pToplevel->cookieValue[iDb] = db->aDb[iDb].pSchema->schema_cookie;
      if( !OMIT_TEMPDB && iDb==1 ){
        sqlite3OpenTempDatabase(pToplevel);
      }
    }
  }
}

/*
** If argument zDb is NULL, then call sqlite3CodeVerifySchema() for each 
** attached database. Otherwise, invoke it for the database named zDb only.
*/
void sqlite3CodeVerifyNamedSchema(Parse *pParse, const char *zDb){
  sqlite3 *db = pParse->db;
  int i;
  for(i=0; i<db->nDb; i++){
    Db *pDb = &db->aDb[i];
    if( pDb->pBt && (!zDb || 0==sqlite3StrICmp(zDb, pDb->zName)) ){
      sqlite3CodeVerifySchema(pParse, i);
    }
  }
}

/*
** Generate VDBE code that prepares for doing an operation that
** might change the database.
**
** This routine starts a new transaction if we are not already within
** a transaction.  If we are already within a transaction, then a checkpoint

#endif
#ifdef SQLITE_OMIT_TRIGGER
  "OMIT_TRIGGER",
#endif
#ifdef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
  "OMIT_TRUNCATE_OPTIMIZATION",
#endif



#ifdef SQLITE_OMIT_UTF16
  "OMIT_UTF16",
#endif
#ifdef SQLITE_OMIT_VACUUM
  "OMIT_VACUUM",
#endif
#ifdef SQLITE_OMIT_VIEW

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Add the new records to the indices as we go.
  */
  for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
    int regIdx;

    int regR;

    if( aRegIdx[iCur]==0 ) continue;  /* Skip unused indices */

    /* Create a key for accessing the index entry */
    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn+1);
    for(i=0; i<pIdx->nColumn; i++){
      int idx = pIdx->aiColumn[i];
      if( idx==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
      }else{
        sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
      }
    }
    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
    sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);
    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn+1);






    /* Find out what action to take in case there is an indexing conflict */
    onError = pIdx->onError;
    if( onError==OE_None ){ 
      sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
      continue;  /* pIdx is not a UNIQUE index */
    }
    if( overrideError!=OE_Default ){

        );
        seenReplace = 1;
        break;
      }
    }
    sqlite3VdbeJumpHere(v, j3);
    sqlite3ReleaseTempReg(pParse, regR);

  }
  
  if( pbMayReplace ){
    *pbMayReplace = seenReplace;
  }
}

*/
int sqlite3_db_config(sqlite3 *db, int op, ...){
  va_list ap;
  int rc;
  va_start(ap, op);
  switch( op ){
    case SQLITE_DBCONFIG_LOOKASIDE: {
      void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
      int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
      int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
      rc = setupLookaside(db, pBuf, sz, cnt);
      break;
    }
    default: {
      static const struct {

    sqlite3SetString(pData->pzErrMsg, db,
      "malformed database schema (%s)", zObj);
    if( zExtra ){
      *pData->pzErrMsg = sqlite3MAppendf(db, *pData->pzErrMsg, 
                                 "%s - %s", *pData->pzErrMsg, zExtra);
    }
  }
  pData->rc = db->mallocFailed ? SQLITE_NOMEM : SQLITE_CORRUPT_BKPT;
}

/*
** This is the callback routine for the code that initializes the
** database.  See sqlite3Init() below for additional information.
** This routine is also called from the OP_ParseSchema opcode of the VDBE.
**

    int testctrl = -1;
    int rc = 0;
    int i, n;
    open_db(p);

    /* convert testctrl text option to value. allow any unique prefix
    ** of the option name, or a numerical value. */
    n = strlen30(azArg[1]);
    for(i=0; i<(int)(sizeof(aCtrl)/sizeof(aCtrl[0])); i++){
      if( strncmp(azArg[1], aCtrl[i].zCtrlName, n)==0 ){
        if( testctrl<0 ){
          testctrl = aCtrl[i].ctrlCode;
        }else{
          fprintf(stderr, "ambiguous option name: \"%s\"\n", azArg[i]);
          testctrl = -1;

** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
** SQLite and sent to all VFSes in place of a call to the xSync method
** when the database connection has [PRAGMA synchronous] set to OFF.)^
** Some specialized VFSes need this signal in order to operate correctly
** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
** VFSes do not need this signal and should silently ignore this opcode.
** Applications should not call [sqlite3_file_control()] with this
** opcode as doing so may disrupt the operation of the specialized VFSes
** that do require it.  
*/
#define SQLITE_FCNTL_LOCKSTATE        1
#define SQLITE_GET_LOCKPROXYFILE      2
#define SQLITE_SET_LOCKPROXYFILE      3
#define SQLITE_LAST_ERRNO             4
#define SQLITE_FCNTL_SIZE_HINT        5

** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
** allocation statistics are disabled by default.
** </dd>
**
** <dt>SQLITE_CONFIG_SCRATCH</dt>
** <dd> ^This option specifies a static memory buffer that SQLite can use for
** scratch memory.  There are three arguments:  A pointer an 8-byte
** aligned memory buffer from which the scratch allocations will be
** drawn, the size of each scratch allocation (sz),
** and the maximum number of scratch allocations (N).  The sz
** argument must be a multiple of 16.
** The first argument must be a pointer to an 8-byte aligned buffer
** of at least sz*N bytes of memory.
** ^SQLite will use no more than two scratch buffers per thread.  So
** N should be set to twice the expected maximum number of threads.

** is invoked.
**
** <dl>
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
** <dd> ^This option takes three additional arguments that determine the 
** [lookaside memory allocator] configuration for the [database connection].
** ^The first argument (the third parameter to [sqlite3_db_config()] is a
** pointer to a memory buffer to use for lookaside memory.
** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
** may be NULL in which case SQLite will allocate the
** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
** size of each lookaside buffer slot.  ^The third argument is the number of
** slots.  The size of the buffer in the first argument must be greater than
** or equal to the product of the second and third arguments.  The buffer
** must be aligned to an 8-byte boundary.  ^If the second argument to

** following this call.  The second parameter may be a NULL pointer, in
** which case the FK enforcement setting is not reported back. </dd>
**
** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
** There should be two additional arguments.
** The first argument is an integer which is 0 to disable triggers,
** positive to enable triggers or negative to leave the setting unchanged.
** The second parameter is a pointer to an integer into which
** is written 0 or 1 to indicate whether triggers are disabled or enabled
** following this call.  The second parameter may be a NULL pointer, in
** which case the trigger setting is not reported back. </dd>
**
** </dl>
*/

** method.
*/
void sqlite3_randomness(int N, void *P);

/*
** CAPI3REF: Compile-Time Authorization Callbacks
**
** ^This routine registers an authorizer callback with a particular
** [database connection], supplied in the first argument.
** ^The authorizer callback is invoked as SQL statements are being compiled
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
** points during the compilation process, as logic is being created
** to perform various actions, the authorizer callback is invoked to
** see if those actions are allowed.  ^The authorizer callback should

** An sqlite3_value object may be either "protected" or "unprotected".
** Some interfaces require a protected sqlite3_value.  Other interfaces
** will accept either a protected or an unprotected sqlite3_value.
** Every interface that accepts sqlite3_value arguments specifies
** whether or not it requires a protected sqlite3_value.
**
** The terms "protected" and "unprotected" refer to whether or not
** a mutex is held.  An internal mutex is held for a protected
** sqlite3_value object but no mutex is held for an unprotected
** sqlite3_value object.  If SQLite is compiled to be single-threaded
** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
** or if SQLite is run in one of reduced mutex modes 
** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
** then there is no distinction between protected and unprotected
** sqlite3_value objects and they can be used interchangeably.  However,

** KEYWORDS: {application-defined SQL function}
** KEYWORDS: {application-defined SQL functions}
**
** ^These functions (collectively known as "function creation routines")
** are used to add SQL functions or aggregates or to redefine the behavior
** of existing SQL functions or aggregates.  The only differences between
** these routines are the text encoding expected for
** the second parameter (the name of the function being created)
** and the presence or absence of a destructor callback for
** the application data pointer.
**
** ^The first parameter is the [database connection] to which the SQL
** function is to be added.  ^If an application uses more than one database
** connection then application-defined SQL functions must be added
** to each database connection separately.

**
** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
** pointers to C-language functions that implement the SQL function or
** aggregate. ^A scalar SQL function requires an implementation of the xFunc
** callback only; NULL pointers must be passed as the xStep and xFinal
** parameters. ^An aggregate SQL function requires an implementation of xStep
** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
** SQL function or aggregate, pass NULL pointers for all three function
** callbacks.
**
** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
** then it is destructor for the application data pointer. 
** The destructor is invoked when the function is deleted, either by being
** overloaded or when the database connection closes.)^
** ^The destructor is also invoked if the call to

** ^The eTextRep argument determines the encoding of strings passed
** to the collating function callback, xCallback.
** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
** force strings to be UTF16 with native byte order.
** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
** on an even byte address.
**
** ^The fourth argument, pArg, is an application data pointer that is passed
** through as the first argument to the collating function callback.
**
** ^The fifth argument, xCallback, is a pointer to the collating function.
** ^Multiple collating functions can be registered using the same name but
** with different eTextRep parameters and SQLite will use whichever
** function requires the least amount of data transformation.
** ^If the xCallback argument is NULL then the collating function is
** deleted.  ^When all collating functions having the same name are deleted,
** that collation is no longer usable.
**
** ^The collating function callback is invoked with a copy of the pArg 
** application data pointer and with two strings in the encoding specified
** by the eTextRep argument.  The collating function must return an
** integer that is negative, zero, or positive
** if the first string is less than, equal to, or greater than the second,
** respectively.  A collating function must always return the same answer
** given the same inputs.  If two or more collating functions are registered
** to the same collation name (using different eTextRep values) then all
** must give an equivalent answer when invoked with equivalent strings.
** The collating function must obey the following properties for all
** strings A, B, and C:
**
** <ol>

** if one or more of following conditions are true:
**
** <ul>
** <li> The soft heap limit is set to zero.
** <li> Memory accounting is disabled using a combination of the
**      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
**      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
** <li> An alternative page cache implementation is specified using
**      [sqlite3_config]([SQLITE_CONFIG_PCACHE],...).
** <li> The page cache allocates from its own memory pool supplied
**      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
**      from the heap.
** </ul>)^
**
** Beginning with SQLite version 3.7.3, the soft heap limit is enforced

typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
typedef struct sqlite3_module sqlite3_module;

/*
** CAPI3REF: Virtual Table Object
** KEYWORDS: sqlite3_module {virtual table module}
**
** This structure, sometimes called a "virtual table module", 
** defines the implementation of a [virtual tables].  
** This structure consists mostly of methods for the module.
**
** ^A virtual table module is created by filling in a persistent
** instance of this structure and passing a pointer to that instance
** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
** ^The registration remains valid until it is replaced by a different

**
** ^(If the row that a BLOB handle points to is modified by an
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
** then the BLOB handle is marked as "expired".
** This is true if any column of the row is changed, even a column
** other than the one the BLOB handle is open on.)^
** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
** ^(Changes written into a BLOB prior to the BLOB expiring are not
** rolled back by the expiration of the BLOB.  Such changes will eventually
** commit if the transaction continues to completion.)^
**
** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
** the opened blob.  ^The size of a blob may not be changed by this
** interface.  Use the [UPDATE] SQL command to change the size of a

  int nColumn;     /* Number of columns in the table used by this index */
  int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
  unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
  Table *pTable;   /* The SQL table being indexed */
  int tnum;        /* Page containing root of this index in database file */
  u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
  u8 bUnordered;   /* Use this index for == or IN queries only */
  char *zColAff;   /* String defining the affinity of each column */
  Index *pNext;    /* The next index associated with the same table */
  Schema *pSchema; /* Schema containing this index */
  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
  char **azColl;   /* Array of collation sequence names for index */
  IndexSample *aSample;    /* Array of SQLITE_INDEX_SAMPLES samples */
};

void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
Vdbe *sqlite3GetVdbe(Parse*);
void sqlite3PrngSaveState(void);
void sqlite3PrngRestoreState(void);
void sqlite3PrngResetState(void);
void sqlite3RollbackAll(sqlite3*);
void sqlite3CodeVerifySchema(Parse*, int);
void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
void sqlite3BeginTransaction(Parse*, int);
void sqlite3CommitTransaction(Parse*);
void sqlite3RollbackTransaction(Parse*);
void sqlite3Savepoint(Parse*, int, Token*);
void sqlite3CloseSavepoints(sqlite3 *);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);

#endif

#ifdef SQLITE_MUTEX_OMIT
  Tcl_SetVar2(interp, "sqlite_options", "mutex", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "mutex", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_MUTEX_NOOP
  Tcl_SetVar2(interp, "sqlite_options", "mutex_noop", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "mutex_noop", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_ALTERTABLE
  Tcl_SetVar2(interp, "sqlite_options", "altertable", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "altertable", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
  Tcl_SetVar2(interp, "sqlite_options", "truncate_opt", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "truncate_opt", "1", TCL_GLOBAL_ONLY);
#endif







#ifdef SQLITE_OMIT_UTF16
  Tcl_SetVar2(interp, "sqlite_options", "utf16", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "utf16", "1", TCL_GLOBAL_ONLY);
#endif

#if defined(SQLITE_OMIT_VACUUM) || defined(SQLITE_OMIT_ATTACH)

    goto trigger_cleanup;
  }
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),
                      zName, sqlite3Strlen30(zName)) ){
    if( !noErr ){
      sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
    }else{
      assert( !db->init.busy );
      sqlite3CodeVerifySchema(pParse, iDb);
    }
    goto trigger_cleanup;
  }

  /* Do not create a trigger on a system table */
  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
    sqlite3ErrorMsg(pParse, "cannot create trigger on system table");

    assert( sqlite3SchemaMutexHeld(db, j, 0) );
    pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName, nName);
    if( pTrigger ) break;
  }
  if( !pTrigger ){
    if( !noErr ){
      sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);
    }else{
      sqlite3CodeVerifyNamedSchema(pParse, zDb);
    }
    pParse->checkSchema = 1;
    goto drop_trigger_cleanup;
  }
  sqlite3DropTriggerPtr(pParse, pTrigger);

drop_trigger_cleanup:

  ** virtual term of that form.
  **
  ** Note that the virtual term must be tagged with TERM_VNULL.  This
  ** TERM_VNULL tag will suppress the not-null check at the beginning
  ** of the loop.  Without the TERM_VNULL flag, the not-null check at
  ** the start of the loop will prevent any results from being returned.
  */
  if( pExpr->op==TK_NOTNULL
   && pExpr->pLeft->op==TK_COLUMN
   && pExpr->pLeft->iColumn>=0
  ){
    Expr *pNewExpr;
    Expr *pLeft = pExpr->pLeft;
    int idxNew;
    WhereTerm *pNewTerm;

    pNewExpr = sqlite3PExpr(pParse, TK_GT,
                            sqlite3ExprDup(db, pLeft, 0),

** non-zero.
**
** This routine can fail if it is unable to load a collating sequence
** required for string comparison, or if unable to allocate memory
** for a UTF conversion required for comparison.  The error is stored
** in the pParse structure.
*/
static int whereEqualScanEst(
  Parse *pParse,       /* Parsing & code generating context */
  Index *p,            /* The index whose left-most column is pTerm */
  Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
  double *pnRow        /* Write the revised row estimate here */
){
  sqlite3_value *pRhs = 0;  /* VALUE on right-hand side of pTerm */
  int iLower, iUpper;       /* Range of histogram regions containing pRhs */

** non-zero.
**
** This routine can fail if it is unable to load a collating sequence
** required for string comparison, or if unable to allocate memory
** for a UTF conversion required for comparison.  The error is stored
** in the pParse structure.
*/
static int whereInScanEst(
  Parse *pParse,       /* Parsing & code generating context */
  Index *p,            /* The index whose left-most column is pTerm */
  ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
  double *pnRow        /* Write the revised row estimate here */
){
  sqlite3_value *pVal = 0;  /* One value from list */
  int iLower, iUpper;       /* Range of histogram regions containing pRhs */

#ifdef SQLITE_ENABLE_STAT2
      if( nEq==0 && pProbe->aSample ) pFirstTerm = pTerm;
#endif
      used |= pTerm->prereqRight;
    }

    /* Determine the value of estBound. */
    if( nEq<pProbe->nColumn && pProbe->bUnordered==0 ){
      int j = pProbe->aiColumn[nEq];
      if( findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE|WO_GT|WO_GE, pIdx) ){
        WhereTerm *pTop = findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE, pIdx);
        WhereTerm *pBtm = findTerm(pWC, iCur, j, notReady, WO_GT|WO_GE, pIdx);
        whereRangeScanEst(pParse, pProbe, nEq, pBtm, pTop, &estBound);
        if( pTop ){
          nBound = 1;

    /* If there is an ORDER BY clause and the index being considered will
    ** naturally scan rows in the required order, set the appropriate flags
    ** in wsFlags. Otherwise, if there is an ORDER BY clause but the index
    ** will scan rows in a different order, set the bSort variable.  */
    if( pOrderBy ){
      if( (wsFlags & WHERE_COLUMN_IN)==0
        && pProbe->bUnordered==0
        && isSortingIndex(pParse, pWC->pMaskSet, pProbe, iCur, pOrderBy,
                          nEq, wsFlags, &rev)
      ){
        wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_ORDERBY;
        wsFlags |= (rev ? WHERE_REVERSE : 0);
      }else{
        bSort = 1;

#
foreach {testid where index rows} {
  500  {x IS NULL AND u='charlie'}         t1u  20
  501  {x=1 AND u='charlie'}               t1x   5
  502  {x IS NULL}                          {} 100
  503  {x=1}                               t1x  50
  504  {x IS NOT NULL}                     t1x  25
  505  {+x IS NOT NULL}                     {} 500
  506  {upper(x) IS NOT NULL}               {} 500

} {
  # Verify that the expected index is used with the expected row count
  do_test analyze5-1.${testid}a {
    set x [lindex [eqp "SELECT * FROM t1 WHERE $where"] 3]
    set idx {}
    regexp {INDEX (t1.) } $x all idx

  execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=?;}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=?) (~86 rows)}}
ifcapable stat2 {
  # If ENABLE_STAT2 is defined, SQLite comes up with a different estimated
  # row count for (c=2) than it does for (c=?).
  do_test analyze7-3.2.2 {
    execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=2;}
  } {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=?) (~51 rows)}}
} else {
  # If ENABLE_STAT2 is not defined, the expected row count for (c=2) is the
  # same as that for (c=?).
  do_test analyze7-3.2.3 {
    execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=2;}
  } {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=?) (~86 rows)}}
}

  }
  set L
} $files

set L [list]
set S ""
foreach {name f} $files {
  if {[permutation] == "journaltest"} {
    lappend L delete
  } else {
    lappend L wal
  }
  append S "
    PRAGMA $name.journal_mode = WAL;
    UPDATE $name.tbl SET x = '$name';
  "
}
do_execsql_test 1.5 $S $L

      6    "SELECT offsets(t1) FROM t1 WHERE t1 MATCH 'aa'"
      7    "SELECT offsets(t1) FROM t1 WHERE t1 MATCH '44'"
      8    "SELECT offsets(t1) FROM t1 WHERE t1 MATCH 'a*'"
    } {
      do_test backcompat-3.7 [list sql1 $q] [sql2 $q]
    }
  }
}

#-------------------------------------------------------------------------
# Test that Rtree tables may be read/written by different versions of 
# SQLite. 
#
set contents {
  CREATE VIRTUAL TABLE t1 USING rtree(id, x1, x2, y1, y2);
}
foreach {id x1 x2 y1 y2} {
  1    -47.64 43.87    33.86 34.42        2    -21.51 17.32    2.05 31.04
  3    -43.67 -38.33    -19.79 3.43       4    32.41 35.16    9.12 19.82
  5    33.28 34.87    14.78 28.26         6    49.31 116.59    -9.87 75.09
  7    -14.93 34.51    -17.64 64.09       8    -43.05 23.43    -1.19 69.44
  9    44.79 133.56    28.09 80.30        10    -2.66 81.47    -41.38 -10.46
  11    -42.89 -3.54    15.76 71.63       12    -3.50 84.96    -11.64 64.95
  13    -45.69 26.25    11.14 55.06       14    -44.09 11.23    17.52 44.45
  15    36.23 133.49    -19.38 53.67      16    -17.89 81.54    14.64 50.61
  17    -41.97 -24.04    -39.43 28.95     18    -5.85 7.76    -6.38 47.02
  19    18.82 27.10    42.82 100.09       20    39.17 113.45    26.14 73.47
  21    22.31 103.17    49.92 106.05      22    -43.06 40.38    -1.75 76.08
  23    2.43 57.27    -14.19 -3.83        24    -47.57 -4.35    8.93 100.06
  25    -37.47 49.14    -29.11 8.81       26    -7.86 75.72    49.34 107.42
  27    1.53 45.49    20.36 49.74         28    -48.48 32.54    28.81 54.45
  29    2.67 39.77    -4.05 13.67         30    4.11 62.88    -47.44 -5.72
  31    -21.47 51.75    37.25 116.09      32    45.59 111.37    -6.43 43.64
  33    35.23 48.29    23.54 113.33       34    16.61 68.35    -14.69 65.97
  35    13.98 16.60    48.66 102.87       36    19.74 23.84    31.15 77.27
  37    -27.61 24.43    7.96 94.91        38    -34.77 12.05    -22.60 -6.29
  39    -25.83 8.71    -13.48 -12.53      40    -17.11 -1.01    18.06 67.89
  41    14.13 71.72    -3.78 39.25        42    23.75 76.00    -16.30 8.23
  43    -39.15 28.63    38.12 125.88      44    48.62 86.09    36.49 102.95
  45    -31.39 -21.98    2.52 89.78       46    5.65 56.04    15.94 89.10
  47    18.28 95.81    46.46 143.08       48    30.93 102.82    -20.08 37.36
  49    -20.78 -3.48    -5.58 35.46       50    49.85 90.58    -24.48 46.29
} {
if {$x1 >= $x2 || $y1 >= $y2} { error "$x1 $x2 $y1 $y2" }
  append contents "INSERT INTO t1 VALUES($id, $x1, $x2, $y1, $y2);"
}
set queries {
  1    "SELECT id FROM t1 WHERE x1>10 AND x2<44"
  2    "SELECT id FROM t1 WHERE y1<100"
  3    "SELECT id FROM t1 WHERE y1<100 AND x1>0"
  4    "SELECT id FROM t1 WHERE y1>10 AND x1>0 AND x2<50 AND y2<550"
}
do_allbackcompat_test {
  if {[code1 {set ::sqlite_options(fts3)}]
   && [code2 {set ::sqlite_options(fts3)}]
  } {

    do_test backcompat-4.1 { sql1 $contents } {}

    foreach {n q} $::queries {
      do_test backcompat-4.2.$n [list sql1 $q] [sql2 $q]
    }

    do_test backcompat-4.3 { sql1 {
      INSERT INTO t1 SELECT id+100, x1+10.0, x2+10.0, y1-10.0, y2-10.0 FROM t1;
    } } {}

    foreach {n q} $::queries {
      do_test backcompat-4.4.$n [list sql1 $q] [sql2 $q]
    }

    do_test backcompat-4.5 { sql2 {
      INSERT INTO t1 SELECT id+200, x1+20.0, x2+20.0, y1-20.0, y2-20.0 FROM t1;
    } } {}

    foreach {n q} $::queries {
      do_test backcompat-4.6.$n [list sql1 $q] [sql2 $q]
    }

  }
}

finish_test

# 2011 April 9
#
# 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 implements regression tests for SQLite library.  The
# focus of this file is testing the various schema modification statements
# that feature "IF EXISTS" or "IF NOT EXISTS" clauses.
#

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

set testprefix exists

# This block of tests is targeted at CREATE XXX IF NOT EXISTS statements.
#
do_multiclient_test tn {

  # TABLE objects.
  #
  do_test 1.$tn.1.1 {
    sql2 { CREATE TABLE t1(x) }
    sql1 { CREATE TABLE IF NOT EXISTS t1(a, b) }
    sql2 { DROP TABLE t1 }
    sql1 { CREATE TABLE IF NOT EXISTS t1(a, b) }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'table' }
  } {t1}

  do_test 1.$tn.1.2 {
    sql2 { CREATE TABLE t2(x) }
    sql1 { CREATE TABLE IF NOT EXISTS t2 AS SELECT * FROM t1 }
    sql2 { DROP TABLE t2 }
    sql1 { CREATE TABLE IF NOT EXISTS t2 AS SELECT * FROM t1 }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'table' }
  } {t1 t2}


  # INDEX objects.
  #
  do_test 1.$tn.2 {
    sql2 { CREATE INDEX i1 ON t1(a) }
    sql1 { CREATE INDEX IF NOT EXISTS i1 ON t1(a, b) }
    sql2 { DROP INDEX i1 }
    sql1 { CREATE INDEX IF NOT EXISTS i1 ON t1(a, b) }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'index' }
  } {i1}

  # VIEW objects.
  #
  do_test 1.$tn.3 {
    sql2 { CREATE VIEW v1 AS SELECT * FROM t1 }
    sql1 { CREATE VIEW IF NOT EXISTS v1 AS SELECT * FROM t1 }
    sql2 { DROP VIEW v1 }
    sql1 { CREATE VIEW IF NOT EXISTS v1 AS SELECT * FROM t1 }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'view' }
  } {v1}

  # TRIGGER objects.
  #
  do_test $tn.4 {
    sql2 { CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN SELECT 1; END }
sql1 { CREATE TRIGGER IF NOT EXISTS tr1 AFTER INSERT ON t1 BEGIN SELECT 1; END }
    sql2 { DROP TRIGGER tr1 }
sql1 { CREATE TRIGGER IF NOT EXISTS tr1 AFTER INSERT ON t1 BEGIN SELECT 1; END }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'trigger' }
  } {tr1}
}

# This block of tests is targeted at DROP XXX IF EXISTS statements.
#
do_multiclient_test tn {

  # TABLE objects.
  #
  do_test 2.$tn.1 {
    sql1 { DROP TABLE IF EXISTS t1 }
    sql2 { CREATE TABLE t1(x) }
    sql1 { DROP TABLE IF EXISTS t1 }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'table' }
  } {}

  # INDEX objects.
  #
  do_test 2.$tn.2 {
    sql1 { CREATE TABLE t2(x) }
    sql1 { DROP INDEX IF EXISTS i2 }
    sql2 { CREATE INDEX i2 ON t2(x) }
    sql1 { DROP INDEX IF EXISTS i2 }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'index' }
  } {}

  # VIEW objects.
  #
  do_test 2.$tn.3 {
    sql1 { DROP VIEW IF EXISTS v1 }
    sql2 { CREATE VIEW v1 AS SELECT * FROM t2 }
    sql1 { DROP VIEW IF EXISTS v1 }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'view' }
  } {}
  
  # TRIGGER objects.
  #
  do_test 2.$tn.4 {
    sql1 { DROP TRIGGER IF EXISTS tr1 }
    sql2 { CREATE TRIGGER tr1 AFTER INSERT ON t2 BEGIN SELECT 1; END }
    sql1 { DROP TRIGGER IF EXISTS tr1 }
    sql2 { SELECT name FROM sqlite_master WHERE type = 'trigger' }
  } {}
}

# This block of tests is targeted at DROP XXX IF EXISTS statements with
# attached databases.
#
do_multiclient_test tn {

  forcedelete test.db2
  do_test 3.$tn.0 {
    sql1 { ATTACH 'test.db2' AS aux }
    sql2 { ATTACH 'test.db2' AS aux }
  } {}

  # TABLE objects.
  #
  do_test 3.$tn.1.1 {
    sql1 { DROP TABLE IF EXISTS aux.t1 }
    sql2 { CREATE TABLE aux.t1(x) }
    sql1 { DROP TABLE IF EXISTS aux.t1 }
    sql2 { SELECT name FROM aux.sqlite_master WHERE type = 'table' }
  } {}
  do_test 3.$tn.1.2 {
    sql1 { DROP TABLE IF EXISTS t1 }
    sql2 { CREATE TABLE aux.t1(x) }
    sql1 { DROP TABLE IF EXISTS t1 }
    sql2 { SELECT name FROM aux.sqlite_master WHERE type = 'table' }
  } {}

  # INDEX objects.
  #
  do_test 3.$tn.2.1 {
    sql1 { CREATE TABLE aux.t2(x) }
    sql1 { DROP INDEX IF EXISTS aux.i2 }
    sql2 { CREATE INDEX aux.i2 ON t2(x) }
    sql1 { DROP INDEX IF EXISTS aux.i2 }
    sql2 { SELECT name FROM aux.sqlite_master WHERE type = 'index' }
  } {}
  do_test 3.$tn.2.2 {
    sql1 { DROP INDEX IF EXISTS i2 }
    sql2 { CREATE INDEX aux.i2 ON t2(x) }
    sql1 { DROP INDEX IF EXISTS i2 }
    sql2 { SELECT name FROM aux.sqlite_master WHERE type = 'index' }
  } {}

  # VIEW objects.
  #
  do_test 3.$tn.3.1 {
    sql1 { DROP VIEW IF EXISTS aux.v1 }
    sql2 { CREATE VIEW aux.v1 AS SELECT * FROM t2 }
    sql1 { DROP VIEW IF EXISTS aux.v1 }
    sql2 { SELECT name FROM aux.sqlite_master WHERE type = 'view' }
  } {}
  do_test 3.$tn.3.2 {
    sql1 { DROP VIEW IF EXISTS v1 }
    sql2 { CREATE VIEW aux.v1 AS SELECT * FROM t2 }
    sql1 { DROP VIEW IF EXISTS v1 }
    sql2 { SELECT name FROM aux.sqlite_master WHERE type = 'view' }
  } {}
  
  # TRIGGER objects.
  #
  do_test 3.$tn.4.1 {
    sql1 { DROP TRIGGER IF EXISTS aux.tr1 }
    sql2 { CREATE TRIGGER aux.tr1 AFTER INSERT ON t2 BEGIN SELECT 1; END }
    sql1 { DROP TRIGGER IF EXISTS aux.tr1 }
    sql2 { SELECT name FROM aux.sqlite_master WHERE type = 'trigger' }
  } {}
  do_test 3.$tn.4.2 {
    sql1 { DROP TRIGGER IF EXISTS tr1 }
    sql2 { CREATE TRIGGER aux.tr1 AFTER INSERT ON t2 BEGIN SELECT 1; END }
    sql1 { DROP TRIGGER IF EXISTS tr1 }
    sql2 { SELECT name FROM aux.sqlite_master WHERE type = 'trigger' }
  } {}
}


finish_test

# If this build of the library does not support auto-vacuum, omit this
# whole file.
ifcapable {!autovacuum || !pragma} {
  finish_test
  return
}

set testprefix incrvacuum2

# Create a database in incremental vacuum mode that has many
# pages on the freelist.
#
do_test incrvacuum2-1.1 {
  execsql {
    PRAGMA page_size=1024;

    BEGIN;
    DELETE FROM abc;
    PRAGMA incremental_vacuum;
    COMMIT;
  }
} {}

integrity_check incrvacuum2-3.3

ifcapable wal {
  # At one point, when a specific page was being extracted from the b-tree
  # free-list (e.g. during an incremental-vacuum), all trunk pages that
  # occurred before the specific page in the free-list trunk were being
  # written to the journal or wal file. This is not necessary. Only the 
  # extracted page and the page that contains the pointer to it need to
  # be journalled.
  #
  # This problem was fixed by [d03d63d77e] (just before 3.7.6 release).
  #
  # This test case builds a database containing many free pages. Then runs
  # "PRAGMA incremental_vacuum(1)" until the db contains zero free pages.
  # Each "PRAGMA incremental_vacuum(1)" should modify at most 4 pages. The
  # worst case is when a trunk page is removed from the end of the db file.
  # In this case pages written are:
  #
  #   1. The previous trunk page (that contains a pointer to the recycled
  #      trunk page), and
  #   2. The leaf page transformed into a trunk page to replace the recycled
  #      page, and
  #   3. The trunk page that contained a pointer to the leaf page used 
  #      in (2), and
  #   4. Page 1. Page 1 is always updated, even in WAL mode, since it contains
  #      the "number of free-list pages" field.
  #
  db close
  forcedelete test.db
  sqlite3 db test.db

  do_execsql_test 4.1 {
    PRAGMA page_size = 512;
    PRAGMA auto_vacuum = 2;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(randomblob(400));
    INSERT INTO t1 SELECT * FROM t1;            --    2
    INSERT INTO t1 SELECT * FROM t1;            --    4
    INSERT INTO t1 SELECT * FROM t1;            --    8
    INSERT INTO t1 SELECT * FROM t1;            --   16
    INSERT INTO t1 SELECT * FROM t1;            --   32
    INSERT INTO t1 SELECT * FROM t1;            --  128
    INSERT INTO t1 SELECT * FROM t1;            --  256
    INSERT INTO t1 SELECT * FROM t1;            --  512
    INSERT INTO t1 SELECT * FROM t1;            -- 1024
    INSERT INTO t1 SELECT * FROM t1;            -- 2048
    INSERT INTO t1 SELECT * FROM t1;            -- 4096
    INSERT INTO t1 SELECT * FROM t1;            -- 8192
    DELETE FROM t1 WHERE oid>512;
    DELETE FROM t1;
  }

  do_test 4.2 {
    execsql { 
      PRAGMA journal_mode = WAL;
      PRAGMA incremental_vacuum(1);
      PRAGMA wal_checkpoint;
    }
    file size test.db-wal
  } {1640}

  do_test 4.3 {
    db close
    sqlite3 db test.db
    set maxsz 0
    while {[file size test.db] > [expr 512*3]} {
      execsql { PRAGMA journal_mode = WAL }
      execsql { PRAGMA wal_checkpoint }
      execsql { PRAGMA incremental_vacuum(1) }
      set newsz [file size test.db-wal]
      if {$newsz>$maxsz} {set maxsz $newsz}
    }
    set maxsz 
  } {2176}
}

finish_test

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

# Skip this whole file if the thread testing code is not enabled
#

if {[run_thread_tests]==0} { finish_test ; return }


if {[llength [info command thread_step]]==0 || [sqlite3 -has-codec]} {
  finish_test
  return
}

# Create some data to work with
#

#
# $Id: thread2.test,v 1.3 2008/10/07 15:25:49 drh Exp $


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


if {[run_thread_tests]==0} { finish_test ; return }




# Skip this whole file if the thread testing code is not enabled
#
if {[llength [info command thread_step]]==0 || [sqlite3 -has-codec]} {
  finish_test
  return
}

# Return true if this build can run the multi-threaded tests.
#
proc run_thread_tests {{print_warning 0}} {
  ifcapable !mutex { 
    set zProblem "SQLite build is not threadsafe"
  }
  ifcapable mutex_noop { 
    set zProblem "SQLite build uses SQLITE_MUTEX_NOOP"
  }
  if {[info commands sqlthread] eq ""} {
    set zProblem "SQLite build is not threadsafe"
  }
  if {![info exists ::tcl_platform(threaded)]} {
    set zProblem "Linked against a non-threadsafe Tcl build"
  }
  if {[info exists zProblem]} {

    file exists test.db-wal
  } 0
  do_test 24.3 {
    file size test.db
  } [expr 84 * 1024]
  do_test 24.4 {
    execsql { 
      PRAGMA cache_size = 200;
      PRAGMA incremental_vacuum;
      PRAGMA wal_checkpoint;
    }
    file size test.db
  } [expr 3 * 1024]
  do_test 24.5 {
    file size test.db-wal