SQLite

**     COPY
**     VACUUM
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.85 2002/03/05 01:11:13 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called after a single SQL statement has been
** parsed and we want to execute the VDBE code to implement 

  ** indices to be created and the table record must come before the 
  ** indices.  Hence, the record number for the table must be allocated
  ** now.
  */
  if( !pParse->initFlag && (v = sqliteGetVdbe(pParse))!=0 ){
    sqliteBeginWriteOperation(pParse);
    if( !isTemp ){
      sqliteVdbeAddOp(v, OP_Integer, db->file_format, 0);
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 1);
      sqliteVdbeAddOp(v, OP_OpenWrite, 0, 2);
      sqliteVdbeChangeP3(v, -1, MASTER_NAME, P3_STATIC);
      sqliteVdbeAddOp(v, OP_NewRecno, 0, 0);
      sqliteVdbeAddOp(v, OP_Dup, 0, 0);
      sqliteVdbeAddOp(v, OP_String, 0, 0);
      sqliteVdbeAddOp(v, OP_PutIntKey, 0, 0);
    }

        assert( pEnd!=0 );
        n = Addr(pEnd->z) - Addr(pParse->sFirstToken.z) + 1;
        sqliteVdbeChangeP3(v, -1, pParse->sFirstToken.z, n);
      }
      sqliteVdbeAddOp(v, OP_MakeRecord, 5, 0);
      sqliteVdbeAddOp(v, OP_PutIntKey, 0, 0);
      changeCookie(db);
      sqliteVdbeAddOp(v, OP_Integer, db->next_cookie, 0);
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 0);
      sqliteVdbeAddOp(v, OP_Close, 0, 0);
    }
    if( pSelect ){
      int op = p->isTemp ? OP_OpenWrAux : OP_OpenWrite;
      sqliteVdbeAddOp(v, op, 1, 0);
      pParse->nTab = 2;
      sqliteSelect(pParse, pSelect, SRT_Table, 1, 0, 0, 0);

      { OP_String,     0, 0,        0}, /* 2 */
      { OP_MemStore,   1, 1,        0},
      { OP_MemLoad,    1, 0,        0}, /* 4 */
      { OP_Column,     0, 2,        0},
      { OP_Ne,         0, ADDR(8),  0},
      { OP_Delete,     0, 0,        0},
      { OP_Next,       0, ADDR(4),  0}, /* 8 */
      { OP_Integer,    0, 0,        0}, /* 9 */
      { OP_SetCookie,  0, 0,        0},
      { OP_Close,      0, 0,        0},
    };
    Index *pIdx;
    sqliteBeginWriteOperation(pParse);
    if( !pTable->isTemp ){
      base = sqliteVdbeAddOpList(v, ArraySize(dropTable), dropTable);
      sqliteVdbeChangeP3(v, base+2, pTable->zName, 0);

      sqliteVdbeResolveLabel(v, lbl2);
      sqliteVdbeAddOp(v, OP_Close, 2, 0);
      sqliteVdbeAddOp(v, OP_Close, 1, 0);
    }
    if( pTable!=0 ){
      if( !isTemp ){
        changeCookie(db);
        sqliteVdbeAddOp(v, OP_Integer, db->next_cookie, 0);
        sqliteVdbeAddOp(v, OP_SetCookie, 0, 0);
        sqliteVdbeAddOp(v, OP_Close, 0, 0);
      }
      sqliteEndWriteOperation(pParse);
    }
  }

  /* Clean up before exiting */

      { OP_MemStore,   1, 1,       0},
      { OP_MemLoad,    1, 0,       0}, /* 4 */
      { OP_Column,     0, 1,       0},
      { OP_Eq,         0, ADDR(9), 0},
      { OP_Next,       0, ADDR(4), 0},
      { OP_Goto,       0, ADDR(10),0},
      { OP_Delete,     0, 0,       0}, /* 9 */
      { OP_Integer,    0, 0,       0}, /* 10 */
      { OP_SetCookie,  0, 0,       0},
      { OP_Close,      0, 0,       0},
    };
    int base;
    Table *pTab = pIndex->pTable;

    sqliteBeginWriteOperation(pParse);
    if( !pTab->isTemp ){

    sqliteSetNString(&zRight, "-", 1, pRight->z, pRight->n, 0);
  }else{
    zRight = sqliteStrNDup(pRight->z, pRight->n);
    sqliteDequote(zRight);
  }
 
  if( sqliteStrICmp(zLeft,"cache_size")==0 ){
    static VdbeOp getCacheSize[] = {
      { OP_ReadCookie,  0, 2,        0},
      { OP_AbsValue,    0, 0,        0},
      { OP_ColumnCount, 1, 0,        0},
      { OP_ColumnName,  0, 0,        "cache_size"},
      { OP_Callback,    1, 0,        0},
    };
    Vdbe *v = sqliteGetVdbe(pParse);
    if( v==0 ) return;
    if( pRight->z==pLeft->z ){
      sqliteVdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
    }else{
      int addr;
      int size = atoi(zRight);
      if( size<0 ) size = -size;
      sqliteBeginWriteOperation(pParse);
      sqliteVdbeAddOp(v, OP_Integer, size, 0);
      sqliteVdbeAddOp(v, OP_ReadCookie, 0, 2);
      addr = sqliteVdbeAddOp(v, OP_Integer, 0, 0);
      sqliteVdbeAddOp(v, OP_Ge, 0, addr+3);
      sqliteVdbeAddOp(v, OP_Negative, 0, 0);
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 2);
      sqliteEndWriteOperation(pParse);
    }
  }else

  if( sqliteStrICmp(zLeft,"synchronous")==0 ){
    static VdbeOp getSync[] = {
      { OP_Integer,     0, 0,        0},
      { OP_ReadCookie,  0, 2,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Lt,          0, 5,        0},
      { OP_AddImm,      1, 0,        0},
      { OP_ColumnCount, 1, 0,        0},
      { OP_ColumnName,  0, 0,        "synchronous"},
      { OP_Callback,    1, 0,        0},
    };
    Vdbe *v = sqliteGetVdbe(pParse);
    if( v==0 ) return;
    if( pRight->z==pLeft->z ){
      sqliteVdbeAddOpList(v, ArraySize(getSync), getSync);
    }else{
      int addr;
      sqliteBeginWriteOperation(pParse);
      sqliteVdbeAddOp(v, OP_ReadCookie, 0, 2);
      sqliteVdbeAddOp(v, OP_AbsValue, 0, 0);
      if( !getBoolean(zRight) ){
        sqliteVdbeAddOp(v, OP_Negative, 0, 0);
      }
      sqliteVdbeAddOp(v, OP_SetCookie, 0, 2);
      sqliteEndWriteOperation(pParse);
    }
  }else

  if( sqliteStrICmp(zLeft, "vdbe_trace")==0 ){
    if( getBoolean(zRight) ){
      db->flags |= SQLITE_VdbeTrace;
    }else{
      db->flags &= ~SQLITE_VdbeTrace;

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.67 2002/03/05 01:11:14 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"

/*
** This is the callback routine for the code that initializes the
** database.  See sqliteInit() below for additional information.

  /* TODO: Do some validity checks on all fields.  In particular,
  ** make sure fields do not contain NULLs. Otherwise we might core
  ** when attempting to initialize from a corrupt database file. */

  assert( argc==4 );
  switch( argv[0][0] ){
    case 'c': {  /* Recommended pager cache size */
      int size = atoi(argv[3]);
      if( size!=0 ){
        sqliteBtreeSetCacheSize(db->pBe, size);
      }
      break;
    }
    case 'f': {  /* File format */
      db->file_format = atoi(argv[3]);
      break;
    }
    case 's': { /* Schema cookie */
      db->schema_cookie = atoi(argv[3]);
      db->next_cookie = db->schema_cookie;

    */
    { OP_Open,       0, 2,  0},
    { OP_String,     0, 0,  "file-format"},
    { OP_String,     0, 0,  0},
    { OP_String,     0, 0,  0},
    { OP_ReadCookie, 0, 1,  0},
    { OP_Callback,   4, 0,  0},

    /* Send the recommended pager cache size to the callback routine
    */
    { OP_String,     0, 0,  "cache-size"},
    { OP_String,     0, 0,  0},
    { OP_String,     0, 0,  0},
    { OP_ReadCookie, 0, 2,  0},
    { OP_Callback,   4, 0,  0},

    /* Send the initial schema cookie to the callback
    */
    { OP_String,     0, 0,  "schema_cookie"},
    { OP_String,     0, 0,  0},
    { OP_String,     0, 0,  0},
    { OP_ReadCookie, 0, 0,  0},
    { OP_Callback,   4, 0,  0},

    /* Check the file format.  If the format number is 2 or more,
    ** then do a single pass through the SQLITE_MASTER table.  For
    ** a format number of less than 2, jump forward to a different
    ** algorithm that makes two passes through the SQLITE_MASTER table,
    ** once for tables and a second time for indices.
    */
    { OP_ReadCookie, 0, 1,  0},
    { OP_Integer,    2, 0,  0},
    { OP_Lt,         0, 28, 0},

    /* This is the code for doing a single scan through the SQLITE_MASTER
    ** table.  This code runs for format 2 and greater.
    */
    { OP_Rewind,     0, 26, 0},
    { OP_Column,     0, 0,  0},           /* 20 */
    { OP_Column,     0, 1,  0},
    { OP_Column,     0, 3,  0},
    { OP_Column,     0, 4,  0},
    { OP_Callback,   4, 0,  0},
    { OP_Next,       0, 20, 0},
    { OP_Close,      0, 0,  0},           /* 26 */
    { OP_Halt,       0, 0,  0},

    /* This is the code for doing two passes through SQLITE_MASTER.  This
    ** code runs for file format 1.
    */
    { OP_Rewind,     0, 48, 0},           /* 28 */
    { OP_Column,     0, 0,  0},           /* 29 */
    { OP_String,     0, 0,  "table"},
    { OP_Ne,         0, 37, 0},
    { OP_Column,     0, 0,  0},
    { OP_Column,     0, 1,  0},
    { OP_Column,     0, 3,  0},
    { OP_Column,     0, 4,  0},
    { OP_Callback,   4, 0,  0},
    { OP_Next,       0, 29, 0},           /* 37 */
    { OP_Rewind,     0, 48, 0},           /* 38 */
    { OP_Column,     0, 0,  0},           /* 39 */
    { OP_String,     0, 0,  "index"},
    { OP_Ne,         0, 47, 0},
    { OP_Column,     0, 0,  0},
    { OP_Column,     0, 1,  0},
    { OP_Column,     0, 3,  0},
    { OP_Column,     0, 4,  0},
    { OP_Callback,   4, 0,  0},
    { OP_Next,       0, 39, 0},           /* 47 */
    { OP_Close,      0, 0,  0},           /* 48 */
    { OP_Halt,       0, 0,  0},
  };

  /* Create a virtual machine to run the initialization program.  Run
  ** the program.  Then delete the virtual machine.
  */
  vdbe = sqliteVdbeCreate(db);

# include <sys/stat.h>
# include <time.h>
#endif
#if OS_WIN
# include <winbase.h>
#endif

/*
** Macros for performance tracing.  Normally turned off
*/
#if 0
static int last_page = 0;
#define SEEK(X)     last_page=(X)
#define TRACE1(X)   fprintf(stderr,X)
#define TRACE2(X,Y) fprintf(stderr,X,Y)
#else
#define SEEK(X)
#define TRACE1(X)
#define TRACE2(X,Y)
#endif


#if OS_UNIX
/*
** Here is the dirt on POSIX advisory locks:  ANSI STD 1003.1 (1996)
** section 6.5.2.2 lines 483 through 490 specify that when a process
** sets or clears a lock, that operation overrides any prior locks set
** by the same process.  It does not explicitly say so, but this implies

** bytes were read successfully and SQLITE_IOERR if anything goes
** wrong.
*/
int sqliteOsRead(OsFile *id, void *pBuf, int amt){
#if OS_UNIX
  int got;
  SimulateIOError(SQLITE_IOERR);
  TRACE2("READ %d\n", last_page);
  got = read(id->fd, pBuf, amt);
  if( got<0 ) got = 0;
  return got==amt ? SQLITE_OK : SQLITE_IOERR;
#endif
#if OS_WIN
  DWORD got;
  SimulateIOError(SQLITE_IOERR);

** Write data from a buffer into a file.  Return SQLITE_OK on success
** or some other error code on failure.
*/
int sqliteOsWrite(OsFile *id, const void *pBuf, int amt){
#if OS_UNIX
  int wrote;
  SimulateIOError(SQLITE_IOERR);
  TRACE2("WRITE %d\n", last_page);
  wrote = write(id->fd, pBuf, amt);
  if( wrote<amt ) return SQLITE_FULL;
  return SQLITE_OK;
#endif
#if OS_WIN
  DWORD wrote;
  SimulateIOError(SQLITE_IOERR);
  if( !WriteFile(id->h, pBuf, amt, &wrote, 0) || (int)wrote<amt ){
    return SQLITE_FULL;
  }
  return SQLITE_OK;
#endif
}

/*
** Move the read/write pointer in a file.
*/
int sqliteOsSeek(OsFile *id, int offset){
  SEEK(offset/1024 + 1);
#if OS_UNIX
  lseek(id->fd, offset, SEEK_SET);
  return SQLITE_OK;
#endif
#if OS_WIN
  SetFilePointer(id->h, offset, 0, FILE_BEGIN);
  return SQLITE_OK;
#endif
}

/*
** Make sure all writes to a particular file are committed to disk.
*/
int sqliteOsSync(OsFile *id){
  SimulateIOError(SQLITE_IOERR);
  TRACE1("SYNC\n");
#if OS_UNIX
  return fsync(id->fd)==0 ? SQLITE_OK : SQLITE_IOERR;
#endif
#if OS_WIN
  return FlushFileBuffers(id->h) ? SQLITE_OK : SQLITE_IOERR;
#endif
}

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.42 2002/03/05 01:11:14 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "os.h"
#include <assert.h>
#include <string.h>

#define DATA_TO_PGHDR(D)  (&((PgHdr*)(D))[-1])
#define PGHDR_TO_EXTRA(P) ((void*)&((char*)(&(P)[1]))[SQLITE_PAGE_SIZE])

/*
** How big to make the hash table used for locating in-memory pages
** by page number.  Knuth says this should be a prime number.
*/
#define N_PG_HASH 2003

/*
** A open page cache is an instance of the following structure.
*/
struct Pager {
  char *zFilename;            /* Name of the database file */
  char *zJournal;             /* Name of the journal file */
  OsFile fd, jfd;             /* File descriptors for database and journal */
  OsFile cpfd;                /* File descriptor for the checkpoint journal */


  int dbSize;                 /* Number of pages in the file */
  int origDbSize;             /* dbSize before the current change */
  int ckptSize, ckptJSize;    /* Size of database and journal at ckpt_begin() */
  int nExtra;                 /* Add this many bytes to each in-memory page */
  void (*xDestructor)(void*); /* Call this routine when freeing pages */
  int nPage;                  /* Total number of in-memory pages */
  int nRef;                   /* Number of in-memory pages with PgHdr.nRef>0 */
  int mxPage;                 /* Maximum number of pages to hold in cache */
  int nHit, nMiss, nOvfl;     /* Cache hits, missing, and LRU overflows */
  u8 journalOpen;             /* True if journal file descriptors is valid */
  u8 ckptOpen;                /* True if the checkpoint journal is open */
  u8 noSync;                  /* Do not sync the journal if true */
  u8 state;                   /* SQLITE_UNLOCK, _READLOCK or _WRITELOCK */
  u8 errMask;                 /* One of several kinds of errors */
  u8 tempFile;                /* zFilename is a temporary file */
  u8 readOnly;                /* True for a read-only database */
  u8 needSync;                /* True if an fsync() is needed on the journal */
  u8 *aInJournal;             /* One bit for each page in the database file */
  u8 *aInCkpt;                /* One bit for each page in the database */
  PgHdr *pFirst, *pLast;      /* List of free pages */
  PgHdr *pAll;                /* List of all pages */
  PgHdr *aHash[N_PG_HASH];    /* Hash table to map page number of PgHdr */
};

/*
** These are bits that can be set in Pager.errMask.

  return rc;
}

/*
** Change the maximum number of in-memory pages that are allowed.
*/
void sqlitepager_set_cachesize(Pager *pPager, int mxPage){
  if( mxPage>=0 ){
    pPager->noSync = 0;
  }else{
    pPager->noSync = 1;
    mxPage = -mxPage;
  }
  if( mxPage>10 ){
    pPager->mxPage = mxPage;
  }
}

/*
** Open a temporary file.  Write the name of the file into zName

      pPg->pPrevAll = 0;
      pPager->pAll = pPg;
      pPager->nPage++;
    }else{
      /* Recycle an older page.  First locate the page to be recycled.
      ** Try to find one that is not dirty and is near the head of
      ** of the free list */

      pPg = pPager->pFirst;
      while( pPg && pPg->dirty ){
        pPg = pPg->pNextFree;
      }

      /* If we could not find a page that has not been used recently
      ** and which is not dirty, then sync the journal and write all
      ** dirty free pages into the database file, thus making them
      ** clean pages and available for recycling.
      **
      ** We have to sync the journal before writing a page to the main
      ** database.  But syncing is a very slow operation.  So after a
      ** sync, it is best to write everything we can back to the main
      ** database to minimize the risk of having to sync again in the
      ** near future.  That is way we write all dirty pages after a
      ** sync.
      */
      if( pPg==0 ){
        int rc = syncAllPages(pPager);
        if( rc!=0 ){
          sqlitepager_rollback(pPager);
          *ppPage = 0;
          return SQLITE_IOERR;
        }
        pPg = pPager->pFirst;

    if( rc!=SQLITE_OK ){
      sqlitepager_rollback(pPager);
      pPager->errMask |= PAGER_ERR_FULL;
      return rc;
    }
    assert( pPager->aInJournal!=0 );
    pPager->aInJournal[pPg->pgno/8] |= 1<<(pPg->pgno&7);
    pPager->needSync = !pPager->noSync;
    pPg->inJournal = 1;
    if( pPager->ckptOpen ){
      pPager->aInCkpt[pPg->pgno/8] |= 1<<(pPg->pgno&7);
      pPg->inCkpt = 1;
    }
  }

  for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
    if( pPg->dirty==0 ) continue;
    rc = sqliteOsSeek(&pPager->fd, (pPg->pgno-1)*SQLITE_PAGE_SIZE);
    if( rc!=SQLITE_OK ) goto commit_abort;
    rc = sqliteOsWrite(&pPager->fd, PGHDR_TO_DATA(pPg), SQLITE_PAGE_SIZE);
    if( rc!=SQLITE_OK ) goto commit_abort;
  }
  if( !pPager->noSync && sqliteOsSync(&pPager->fd)!=SQLITE_OK ){
    goto commit_abort;
  }
  rc = pager_unwritelock(pPager);
  pPager->dbSize = -1;
  return rc;

  /* Jump here if anything goes wrong during the commit process.
  */
commit_abort:

**
*************************************************************************
** This file contains SQLite's grammar for SQL.  Process this file
** using the lemon parser generator to generate C code that runs
** the parser.  Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
** @(#) $Id: parse.y,v 1.56 2002/03/05 01:11:14 drh Exp $
*/
%token_prefix TK_
%token_type {Token}
%default_type {Token}
%extra_argument {Parse *pParse}
%syntax_error {
  sqliteSetString(&pParse->zErrMsg,"syntax error",0);

///////////////////////////// The PRAGMA command /////////////////////////////
//
cmd ::= PRAGMA ids(X) EQ ids(Y).         {sqlitePragma(pParse,&X,&Y,0);}
cmd ::= PRAGMA ids(X) EQ ON(Y).          {sqlitePragma(pParse,&X,&Y,0);}
cmd ::= PRAGMA ids(X) EQ plus_num(Y).    {sqlitePragma(pParse,&X,&Y,0);}
cmd ::= PRAGMA ids(X) EQ minus_num(Y).   {sqlitePragma(pParse,&X,&Y,1);}
cmd ::= PRAGMA ids(X) LP ids(Y) RP.      {sqlitePragma(pParse,&X,&Y,0);}
cmd ::= PRAGMA ids(X).                   {sqlitePragma(pParse,&X,&X,0);}
plus_num(A) ::= plus_opt number(X).   {A = X;}
minus_num(A) ::= MINUS number(X).     {A = X;}
number(A) ::= INTEGER(X).  {A = X;}
number(A) ::= FLOAT(X).    {A = X;}
plus_opt ::= PLUS.
plus_opt ::= .

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.102 2002/03/05 01:11:14 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

/*
** The maximum number of in-memory pages to use for the main database
** table and for temporary tables.
*/
#define MAX_PAGES   2000
#define TEMP_PAGES   500

/*
** Integers of known sizes.  These typedefs might change for architectures
** where the sizes very.  Preprocessor macros are available so that the
** types can be conveniently redefined at compile-type.  Like this:
**
**         cc '-DUINTPTR_TYPE=long long int' ...

** type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.131 2002/03/05 01:11:14 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveTo or the OP_Next opcode.  The test

** number for the database schema.  Everytime the schema changes, the
** cookie changes to a new random value.  This opcode is used during
** initialization to read the initial cookie value so that subsequent
** database accesses can verify that the cookie has not changed.
**
** If P2>0, then read global database parameter number P2.  There is
** a small fixed number of global database parameters.  P2==1 is the
** database version number.  P2==2 is the recommended pager cache size.
** Other parameters are currently unused.
**
** There must be a read-lock on the database (either a transaction
** must be started or there must be an open cursor) before
** executing this instruction.
*/
case OP_ReadCookie: {
  int i = ++p->tos;
  int aMeta[SQLITE_N_BTREE_META];
  assert( pOp->p2<SQLITE_N_BTREE_META );
  VERIFY( if( NeedStack(p, p->tos) ) goto no_mem; )
  rc = sqliteBtreeGetMeta(pBt, aMeta);
  aStack[i].i = aMeta[1+pOp->p2];
  aStack[i].flags = STK_Int;
  break;
}

/* Opcode: SetCookie * P2 *
**
** When P2==0,
** this operation changes the value of the schema cookie on the database.
** The new value is top of the stack.
** When P2>0, the value of global database parameter
** number P2 is changed.  See ReadCookie for more information about
** global database parametes.
**
** The schema cookie changes its value whenever the database schema changes.
** That way, other processes can recognize when the schema has changed
** and reread it.
**
** A transaction must be started before executing this opcode.
*/
case OP_SetCookie: {
  int aMeta[SQLITE_N_BTREE_META];
  assert( pOp->p2<SQLITE_N_BTREE_META );
  VERIFY( if( p->tos<0 ) goto not_enough_stack; )
  Integerify(p, p->tos)
  rc = sqliteBtreeGetMeta(pBt, aMeta);
  if( rc==SQLITE_OK ){
    aMeta[1+pOp->p2] = aStack[p->tos].i;
    rc = sqliteBtreeUpdateMeta(pBt, aMeta);
  }
  POPSTACK;
  break;
}

/* Opcode: VerifyCookie P1 P2 *
**
** Check the value of global database parameter number P2 and make
** sure it is equal to P1.  P2==0 is the schema cookie.  P1==1 is

#!/usr/bin/tclsh
#
# Run this script using TCLSH to do a speed comparison between
# various versions of SQLite and PostgreSQL and MySQL
#

# Run a test
#
set cnt 0
proc runtest {title sqlfile} {
  global cnt
  incr cnt
  puts "<h2>Test $cnt: $title</h2>"
  set fd [open $sqlfile r]
  set sql [string trim [read $fd [file size $sqlfile]]]
  close $fd
  set sx [split $sql \n]
  set n [llength $sx]
  if {$n>8} {
    set sql {}
    for {set i 0} {$i<3} {incr i} {append sql [lindex $sx $i]<br>\n}
    append sql  "<i>... [expr {$n-6}] lines omitted</i><br>\n"
    for {set i [expr {$n-3}]} {$i<$n} {incr i} {
      append sql [lindex $sx $i]<br>\n
    }
  } else {
    regsub -all \n [string trim $sql] <br> sql
  }
  puts "<blockquote>"
  puts "$sql"
  puts "</blockquote><table border=0 cellpadding=0 cellspacing=5>"
  set format {<tr><td>%s</td><td align="right">%.3f</td></tr>}
  set t [time "exec psql drh <$sqlfile" 1]
  set t [expr {[lindex $t 0]/1000000.0}]
  puts [format $format PostgreSQL: $t]
  set t [time "exec mysql drh <$sqlfile" 1]
  set t [expr {[lindex $t 0]/1000000.0}]
  puts [format $format MySQL: $t]
#  set t [time "exec ./sqlite232 s232.db <$sqlfile" 1]
#  set t [expr {[lindex $t 0]/1000000.0}]
#  puts [format $format {SQLite 2.3.2:} $t]
#  set t [time "exec ./sqlite-100 s100.db <$sqlfile" 1]
#  set t [expr {[lindex $t 0]/1000000.0}]
#  puts [format $format {SQLite 2.4 (cache=100):} $t]
  set t [time "exec ./sqlite240 s2k.db <$sqlfile" 1]
  set t [expr {[lindex $t 0]/1000000.0}]
  puts [format $format {SQLite 2.4 (cache=2000):} $t]
  set t [time "exec ./sqlite240 sns.db <$sqlfile" 1]
  set t [expr {[lindex $t 0]/1000000.0}]
  puts [format $format {SQLite 2.4 (nosync):} $t]
  puts "</table>"
}

# Initialize the environment
#
expr srand(1)
catch {exec /bin/sh -c {rm -f s*.db}}
set fd [open clear.sql w]
puts $fd {
  drop table t1;
  drop table t2;
}
close $fd
catch {exec psql drh <clear.sql}
catch {exec mysql drh <clear.sql}
set fd [open 2kinit.sql w]
puts $fd {PRAGMA cache_size=2000; PRAGMA synchronous=on;}
close $fd
exec ./sqlite240 s2k.db <2kinit.sql
set fd [open nosync-init.sql w]
puts $fd {PRAGMA cache_size=2000; PRAGMA synchronous=off;}
close $fd
exec ./sqlite240 sns.db <nosync-init.sql
set ones {zero one two three four five six seven eight nine
          ten eleven twelve thirteen fourteen fifteen sixteen seventeen
          eighteen nineteen}
set tens {{} ten twenty thirty forty fifty sixty seventy eighty ninety}
proc number_name {n} {
  if {$n>=1000} {
    set txt "[number_name [expr {$n/1000}]] thousand"
    set n [expr {$n%1000}]
  } else {
    set txt {}
  }
  if {$n>100} {
    append txt " [lindex $::ones [expr {$n/100}]] hundred"
    set n [expr {$n%100}]
  }
  if {$n>19} {
    append txt " [lindex $::tens [expr {$n/10}]]"
    set n [expr {$n%10}]
  }
  if {$n>0} {
    append txt " [lindex $::ones $n]"
  }
  set txt [string trim $txt]
  if {$txt==""} {set txt zero}
  return $txt
}

# TEST 1
#
set fd [open test1.sql w]
puts $fd "CREATE TABLE t1(a INTEGER, b INTEGER, c VARCHAR(100));"
for {set i 1} {$i<=1000} {incr i} {
  set r [expr {int(rand()*100000)}]
  puts $fd "INSERT INTO t1 VALUES($i,$r,'[number_name $r]');"
}
close $fd
runtest {1000 INSERTs} test1.sql

# TEST 2
#
set fd [open test2.sql w]
puts $fd "BEGIN;"
puts $fd "CREATE TABLE t2(a INTEGER, b INTEGER, c VARCHAR(100));"
for {set i 1} {$i<=25000} {incr i} {
  set r [expr {int(rand()*500000)}]
  puts $fd "INSERT INTO t2 VALUES($i,$r,'[number_name $r]');"
}
puts $fd "COMMIT;"
close $fd
runtest {25000 INSERTs in a transaction} test2.sql

# TEST 3
#
set fd [open test3.sql w]
for {set i 0} {$i<100} {incr i} {
  set lwr [expr {$i*100}]
  set upr [expr {($i+10)*100}]
  puts $fd "SELECT count(*), avg(b) FROM t2 WHERE b>=$lwr AND b<$upr;"
}
close $fd
runtest {100 SELECTs without an index} test3.sql

# TEST 4
#
set fd [open test4.sql w]
puts $fd {CREATE INDEX i2a ON t2(a);}
puts $fd {CREATE INDEX i2b ON t2(b);}
close $fd
runtest {Creating an index} test4.sql

# TEST 5
#
set fd [open test5.sql w]
for {set i 0} {$i<5000} {incr i} {
  set lwr [expr {$i*100}]
  set upr [expr {($i+1)*100}]
  puts $fd "SELECT count(*), avg(b) FROM t2 WHERE b>=$lwr AND b<$upr;"
}
close $fd
runtest {5000 SELECTs with an index} test5.sql

# TEST 6
#
set fd [open test6.sql w]
puts $fd "BEGIN;"
for {set i 0} {$i<100} {incr i} {
  set lwr [expr {$i*10}]
  set upr [expr {($i+1)*10}]
  puts $fd "UPDATE t1 SET b=b*2 WHERE a>=$lwr AND a<$upr;"
}
puts $fd "COMMIT;"
close $fd
runtest {100 UPDATEs without an index} test6.sql


# TEST 7
set fd [open test7.sql w]
puts $fd "BEGIN;"
for {set i 1} {$i<=25000} {incr i} {
  puts $fd "UPDATE t2 SET b=b+a WHERE a=$i;"
}
puts $fd "COMMIT;"
close $fd
runtest {25000 UPDATEs with an index} test7.sql

# TEST 8
set fd [open test8.sql w]
puts $fd "BEGIN;"
puts $fd "INSERT INTO t1 SELECT * FROM t2;"
puts $fd "INSERT INTO t2 SELECT * FROM t1;"
puts $fd "COMMIT;"
close $fd
runtest {INSERTs from a SELECT} test8.sql

# TEST 9
#
set fd [open test9.sql w]
puts $fd {DELETE FROM t2 WHERE c LIKE '%fifty%';}
close $fd
runtest {DELETE without an index} test9.sql

# TEST 10
#
set fd [open test10.sql w]
puts $fd {DELETE FROM t2 WHERE a>10 AND a<20000;}
close $fd
runtest {DELETE with an index} test10.sql

# TEST 11
#
set fd [open test11.sql w]
puts $fd {INSERT INTO t2 SELECT * FROM t1;}
close $fd
runtest {A big INSERT after a big DELETE} test11.sql

# TEST 12
#
set fd [open test12.sql w]
puts $fd {BEGIN;}
puts $fd {DELETE FROM t1;}
for {set i 1} {$i<=1000} {incr i} {
  set r [expr {int(rand()*100000)}]
  puts $fd "INSERT INTO t1 VALUES($i,$r,'[number_name $r]');"
}
puts $fd {COMMIT;}
close $fd
runtest {A big DELETE followed by many small INSERTs} test12.sql

# TEST 13
#
set fd [open test13.sql w]
puts $fd {DROP TABLE t1;}
puts $fd {DROP TABLE t2;}
close $fd
runtest {DROP TABLE} test13.sql

<li>Added the subquery flattening optimizer.</li>
<li>Modified the B-Tree and Pager modules so that disk pages that do not
    contain real data (free pages) are not journalled and are not
    written from memory back to the disk when they change.  This does not 
    impact database integrity, since the
    pages contain no real data, but it does make large INSERT operations
    about 2.5 times faster and large DELETEs about 5 times faster.</li>
<li>Made the CACHE_SIZE pragma persistent</li>
<li>Added the SYNCHRONOUS pragma</li>
}

chng {2002 Feb 18 (2.3.3)} {
<li>Allow identifiers to be quoted in square brackets, for compatibility
    with MS-Access.</li>
<li>Added support for sub-queries in the FROM clause of a SELECT.</li>
<li>More efficient implementation of sqliteFileExists() under Windows.