SQLite

#endif
#ifdef SQLITE_DEBUG
  extern int sqlite3WhereTrace;
  extern int sqlite3OSTrace;
  extern int sqlite3WalTrace;
#endif
#ifdef SQLITE_TEST
  extern char sqlite3_query_plan[];
  static char *query_plan = sqlite3_query_plan;
#ifdef SQLITE_ENABLE_FTS3
  extern int sqlite3_fts3_enable_parentheses;
#endif
#endif

  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);

      (char*)&pzNeededCollation, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
#endif
#if SQLITE_OS_WIN
  Tcl_LinkVar(interp, "sqlite_os_type",
      (char*)&sqlite3_os_type, TCL_LINK_INT);
#endif
#ifdef SQLITE_TEST


  Tcl_LinkVar(interp, "sqlite_query_plan",
      (char*)&query_plan, TCL_LINK_STRING|TCL_LINK_READ_ONLY);

#endif
#ifdef SQLITE_DEBUG
  Tcl_LinkVar(interp, "sqlite_where_trace",
      (char*)&sqlite3WhereTrace, TCL_LINK_INT);
  Tcl_LinkVar(interp, "sqlite_os_trace",
      (char*)&sqlite3OSTrace, TCL_LINK_INT);
#ifndef SQLITE_OMIT_WAL

#define WO_SINGLE 0x0ff       /* Mask of all non-compound WO_* values */

/*
** Value for wsFlags returned by bestIndex() and stored in
** WhereLevel.wsFlags.  These flags determine which search
** strategies are appropriate.
*/
#define WHERE_ROWID_EQ     0x00000001  /* rowid=EXPR or rowid IN (...) */
#define WHERE_ROWID_RANGE  0x00000002  /* rowid<EXPR and/or rowid>EXPR */
#define WHERE_NULL_OK      0x00000004  /* Ok to use WO_ISNULL */
#define WHERE_IPK          0x00000008  /* x is the INTEGER PRIMARY KEY */
#define WHERE_COLUMN_EQ    0x00000010  /* x=EXPR or x IN (...) or x IS NULL */
#define WHERE_COLUMN_RANGE 0x00000020  /* x<EXPR and/or x>EXPR */
#define WHERE_COLUMN_IN    0x00000040  /* x IN (...) */
#define WHERE_COLUMN_NULL  0x00000080  /* x IS NULL */
#define WHERE_INDEXED      0x000000f0  /* Anything that uses an index */
#define WHERE_NOT_FULLSCAN 0x000200f3  /* Does not do a full table scan */
#define WHERE_IN_ABLE      0x000100f1  /* Able to support an IN operator */
#define WHERE_TOP_LIMIT    0x00000100  /* x<EXPR or x<=EXPR constraint */
#define WHERE_BTM_LIMIT    0x00000200  /* x>EXPR or x>=EXPR constraint */
#define WHERE_BOTH_LIMIT   0x00000300  /* Both x>EXPR and x<EXPR */
#define WHERE_IDX_ONLY     0x00000400  /* Use index only - omit table */
#define WHERE_ORDERED      0x00000800  /* Output will appear in correct order */
#define WHERE_REVERSE      0x00001000  /* Scan in reverse order */
#define WHERE_UNIQUE       0x00002000  /* Selects no more than one row */
#define WHERE_ALL_UNIQUE   0x00004000  /* This and all prior have one row */
#define WHERE_OB_UNIQUE    0x00008000  /* Values in ORDER BY columns are 
                                       ** different for every output row */
#define WHERE_VIRTUALTABLE 0x00010000  /* Use virtual-table processing */
#define WHERE_MULTI_OR     0x00020000  /* OR using multiple indices */
#define WHERE_TEMP_INDEX   0x00040000  /* Uses an ephemeral index */
#define WHERE_DISTINCT     0x00080000  /* Correct order for DISTINCT */
#define WHERE_COVER_SCAN   0x00100000  /* Full scan of a covering index */
#define WHERE_SINGLE_ROW   0x00200000  /* No more than one row guaranteed */

/*
** This module contains many separate subroutines that work together to
** find the best indices to use for accessing a particular table in a query.
** An instance of the following structure holds context information about the
** index search so that it can be more easily passed between the various
** routines.

    eType = sqlite3FindInIndex(pParse, pX, 0);
    if( eType==IN_INDEX_INDEX_DESC ){
      testcase( bRev );
      bRev = !bRev;
    }
    iTab = pX->iTable;
    sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
    assert( pLoop->wsFlags & WHERE_IN_ABLE );

    if( pLevel->u.in.nIn==0 ){
      pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
    }
    pLevel->u.in.nIn++;
    pLevel->u.in.aInLoop =
       sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
                              sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);

    if( testOp!=OP_Noop ){
      iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
      sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
      sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
    }
  }else if( pLoop->wsFlags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ|WHERE_IDX_ONLY) ){

    /* Case 4: A scan using an index.
    **
    **         The WHERE clause may contain zero or more equality 
    **         terms ("==" or "IN" operators) that refer to the N
    **         left-most columns of the index. It may also contain
    **         inequality constraints (>, <, >= or <=) on the indexed
    **         column that immediately follows the N equalities. Only 

    }
  }
  sqlite3ReleaseTempReg(pParse, iReleaseReg);

  return newNotReady;
}

#if defined(SQLITE_TEST)
/*
** The following variable holds a text description of query plan generated
** by the most recent call to sqlite3WhereBegin().  Each call to WhereBegin
** overwrites the previous.  This information is used for testing and
** analysis only.
*/
char sqlite3_query_plan[BMS*2*40];  /* Text of the join */
static int nQPlan = 0;              /* Next free slow in _query_plan[] */

#endif /* SQLITE_TEST */

#ifdef WHERETRACE_ENABLED
/*
** Print a WhereLoop object for debugging purposes
*/
static void whereLoopPrint(WhereLoop *p, SrcList *pTabList){
  int nb = 2*((pTabList->nSrc+15)/16);
  struct SrcList_item *pItem = pTabList->a + p->iTab;

                p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);
    }else{
      z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
    }
    sqlite3DebugPrintf(" %-15s", z);
    sqlite3_free(z);
  }
  sqlite3DebugPrintf(" fg %08x N %d", p->wsFlags, p->nTerm);
  sqlite3DebugPrintf(" cost %.2g,%.2g,%.2g\n",
                     p->prereq, p->rSetup, p->rRun, p->nOut);
}
#endif

/*
** Deallocate internal memory used by a WhereLoop object
*/
static void whereLoopClear(sqlite3 *db, WhereLoop *p){
  sqlite3DbFree(db, p->aTerm);
  p->aTerm = 0;
  p->nTerm = 0;
  if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
    if( p->u.vtab.needFree ) sqlite3_free(p->u.vtab.idxStr);
    p->u.vtab.needFree = 0;
    p->u.vtab.idxStr = 0;




  }
}

/*
** Delete a WhereLoop object
*/
static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
  whereLoopClear(db, p);
  sqlite3DbFree(db, p);
}

/*
** Free a WhereInfo structure
*/
static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
  if( ALWAYS(pWInfo) ){
    int i;
    for(i=0; i<pWInfo->nLevel; i++){
      if( pWInfo->a[i].pWLoop->wsFlags & WHERE_TEMP_INDEX ){
        Index *pIdx = pWInfo->a[i].pWLoop->u.btree.pIndex;
        if( pIdx ){
          sqlite3DbFree(db, pIdx->zColAff);
          sqlite3DbFree(db, pIdx);
        }
      }
    }
    whereClauseClear(pWInfo->pWC);
    while( pWInfo->pLoops ){
      WhereLoop *p = pWInfo->pLoops;
      pWInfo->pLoops = p->pNextLoop;
      whereLoopDelete(db, p);
    }
    sqlite3DbFree(db, pWInfo);

        nIn = 25;
      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
        /* "x IN (value, value, ...)" */
        nIn = pExpr->x.pList->nExpr;
      }
      pNew->u.btree.nEq++;
      pNew->nOut = (double)iRowEst * nInMul * nIn;
    }else if( pTerm->eOperator & (WO_EQ|WO_ISNULL) ){
      pNew->wsFlags |= WHERE_COLUMN_EQ;




      pNew->u.btree.nEq++;
      pNew->nOut = (double)iRowEst * nInMul;
    }else if( pTerm->eOperator & (WO_GT|WO_GE) ){
      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
      pNew->nOut = savedLoop.nOut/3;
    }else if( pTerm->eOperator & (WO_LT|WO_LE) ){
      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;

      int j;
      for(j=pProbe->nColumn-1; j>=0; j--){
        int x = pProbe->aiColumn[j];
        if( x<BMS-1 ){
          m &= ~(((Bitmask)1)<<x);
        }
      }
      pNew->wsFlags = (m==0) ? WHERE_IDX_ONLY : 0;

      /* Full scan via index */
      if( (m==0 || b) && pProbe->bUnordered==0 ){
        pNew->iSortIdx = b ? iSortIdx : 0;
        pNew->nOut = rSize;
        pNew->rRun = (m==0) ? (rSize + rLogSize)*(1+b) : (rSize*rLogSize);
        rc = whereLoopInsert(pBuilder, pNew);

  for(ii=0; ii<nTabList; ii++){
    pLevel = &pWInfo->a[ii];
    explainOneScan(pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags);
    notReady = codeOneLoopStart(pWInfo, ii, wctrlFlags, notReady);
    pWInfo->iContinue = pLevel->addrCont;
  }

#if defined(SQLITE_TEST) && 0  /* For testing and debugging use only */
  /* Record in the query plan information about the current table
  ** and the index used to access it (if any).  If the table itself
  ** is not used, its name is just '{}'.  If no index is used
  ** the index is listed as "{}".  If the primary key is used the
  ** index name is '*'.
  */
  for(ii=0; ii<nTabList; ii++){
    char *z;
    int n;
    int w;
    struct SrcList_item *pTabItem;

    pLevel = &pWInfo->a[ii];
    w = pLevel->plan.wsFlags;
    pTabItem = &pTabList->a[pLevel->iFrom];
    z = pTabItem->zAlias;
    if( z==0 ) z = pTabItem->pTab->zName;
    n = sqlite3Strlen30(z);
    if( n+nQPlan < sizeof(sqlite3_query_plan)-10 ){
      if( (w & WHERE_IDX_ONLY)!=0 && (w & WHERE_COVER_SCAN)==0 ){
        memcpy(&sqlite3_query_plan[nQPlan], "{}", 2);
        nQPlan += 2;
      }else{
        memcpy(&sqlite3_query_plan[nQPlan], z, n);
        nQPlan += n;
      }
      sqlite3_query_plan[nQPlan++] = ' ';
    }
    testcase( w & WHERE_ROWID_EQ );
    testcase( w & WHERE_ROWID_RANGE );
    if( w & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
      memcpy(&sqlite3_query_plan[nQPlan], "* ", 2);
      nQPlan += 2;
    }else if( (w & WHERE_INDEXED)!=0 && (w & WHERE_COVER_SCAN)==0 ){
      n = sqlite3Strlen30(pLevel->plan.u.pIdx->zName);
      if( n+nQPlan < sizeof(sqlite3_query_plan)-2 ){
        memcpy(&sqlite3_query_plan[nQPlan], pLevel->plan.u.pIdx->zName, n);
        nQPlan += n;
        sqlite3_query_plan[nQPlan++] = ' ';
      }
    }else{
      memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3);
      nQPlan += 3;
    }
  }
  while( nQPlan>0 && sqlite3_query_plan[nQPlan-1]==' ' ){
    sqlite3_query_plan[--nQPlan] = 0;
  }
  sqlite3_query_plan[nQPlan] = 0;
  nQPlan = 0;
#endif /* SQLITE_TEST // Testing and debugging use only */

  /* Record the continuation address in the WhereInfo structure.  Then
  ** clean up and return.
  */
  return pWInfo;

  /* Jump here if malloc fails */
whereBeginError:
  if( pWInfo ){
    pParse->nQueryLoop = pWInfo->savedNQueryLoop;
    whereInfoFree(db, pWInfo);

# "sqlite_search_count" which tallys the number of executions of MoveTo
# and Next operators in the VDBE.  By verifing that the search count is
# small we can be assured that indices are being used properly.
#
do_test where-1.1.1 {
  count {SELECT x, y, w FROM t1 WHERE w=10}
} {3 121 10 3}
do_test where-1.1.2 {
  set sqlite_query_plan
} {t1 i1w}
do_test where-1.1.3 {
  db status step
} {0}
do_test where-1.1.4 {
  db eval {SELECT x, y, w FROM t1 WHERE +w=10}
} {3 121 10}
do_test where-1.1.5 {
  db status step
} {99}
do_test where-1.1.6 {
  set sqlite_query_plan
} {t1 {}}
do_test where-1.1.7 {
  count {SELECT x, y, w AS abc FROM t1 WHERE abc=10}
} {3 121 10 3}
do_test where-1.1.8 {
  set sqlite_query_plan
} {t1 i1w}
do_test where-1.1.9 {
  db status step
} {0}
do_test where-1.2.1 {
  count {SELECT x, y, w FROM t1 WHERE w=11}
} {3 144 11 3}
do_test where-1.2.2 {
  count {SELECT x, y, w AS abc FROM t1 WHERE abc=11}
} {3 144 11 3}
do_test where-1.3.1 {
  count {SELECT x, y, w AS abc FROM t1 WHERE 11=w}
} {3 144 11 3}
do_test where-1.3.2 {
  count {SELECT x, y, w AS abc FROM t1 WHERE 11=abc}
} {3 144 11 3}
do_test where-1.4.1 {
  count {SELECT w, x, y FROM t1 WHERE 11=w AND x>2}
} {11 3 144 3}
do_test where-1.4.2 {
  set sqlite_query_plan
} {t1 i1w}
do_test where-1.4.3 {
  count {SELECT w AS a, x AS b, y FROM t1 WHERE 11=a AND b>2}
} {11 3 144 3}
do_test where-1.4.4 {
  set sqlite_query_plan
} {t1 i1w}
do_test where-1.5 {
  count {SELECT x, y FROM t1 WHERE y<200 AND w=11 AND x>2}
} {3 144 3}
do_test where-1.5.2 {
  set sqlite_query_plan
} {t1 i1w}
do_test where-1.6 {
  count {SELECT x, y FROM t1 WHERE y<200 AND x>2 AND w=11}
} {3 144 3}
do_test where-1.7 {
  count {SELECT x, y FROM t1 WHERE w=11 AND y<200 AND x>2}
} {3 144 3}
do_test where-1.8 {
  count {SELECT x, y FROM t1 WHERE w>10 AND y=144 AND x=3}
} {3 144 3}
do_test where-1.8.2 {
  set sqlite_query_plan
} {t1 i1xy}
do_test where-1.8.3 {
  count {SELECT x, y FROM t1 WHERE y=144 AND x=3}
  set sqlite_query_plan
} {{} i1xy}
do_test where-1.9 {
  count {SELECT x, y FROM t1 WHERE y=144 AND w>10 AND x=3}
} {3 144 3}
do_test where-1.10 {
  count {SELECT x, y FROM t1 WHERE x=3 AND w>=10 AND y=121}
} {3 121 3}
do_test where-1.11 {