SQLite

    }
  }
  *pNew = savedLoop;
  return rc;
}

/*
** Add all WhereLoop objects a single table of the join were the table
** is idenfied by pBuilder->pNew->iTab.  That table is guaranteed to be
** a b-tree table, not a virtual table.
*/
static int whereLoopAddBtree(
  WhereLoopBuilder *pBuilder, /* WHERE clause information */
  Bitmask mExtra              /* Extra prerequesites for using this table */
){
  Index *pProbe;              /* An index we are evaluating */
  Index sPk;                  /* A fake index object for the primary key */
  tRowcnt aiRowEstPk[2];      /* The aiRowEst[] value for the sPk index */
  int aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
  struct SrcList_item *pSrc;  /* The FROM clause btree term to add */
  WhereLoop *pNew;            /* Template WhereLoop object */
  int rc = SQLITE_OK;         /* Return code */
  double rSize;               /* number of rows in the table */
  double rLogSize;            /* Logarithm of the number of rows in the table */

  pNew = pBuilder->pNew;
  pSrc = pBuilder->pTabList->a + pNew->iTab;
  assert( !IsVirtual(pSrc->pTab) );

  if( pSrc->pIndex ){
    /* An INDEXED BY clause specifies a particular index to use */
    pProbe = pSrc->pIndex;
  }else{
    /* There is no INDEXED BY clause.  Create a fake Index object in local
    ** variable sPk to represent the rowid primary key index.  Make this

    ** considered. */
    if( pSrc->pIndex ) break;
  }
  return rc;
}

/*
** Add all WhereLoop objects for a table of the join identified by
** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
*/
static int whereLoopAddVirtual(
  WhereLoopBuilder *pBuilder,  /* WHERE clause information */
  Bitmask mExtra               /* Extra prerequesites for using this table */
){
  Parse *pParse;               /* The parsing context */
  WhereClause *pWC;            /* The WHERE clause */

  pParse = pBuilder->pParse;
  db = pParse->db;
  pWC = pBuilder->pWC;
  pNew = pBuilder->pNew;
  pSrc = &pBuilder->pTabList->a[pNew->iTab];
  pTab = pSrc->pTab;
  assert( IsVirtual(pTab) );
  pIdxInfo = allocateIndexInfo(pParse, pWC, pSrc, pBuilder->pOrderBy);
  if( pIdxInfo==0 ) return SQLITE_NOMEM;
  pNew->prereq = 0;
  pNew->rSetup = 0;
  pNew->wsFlags = WHERE_VIRTUALTABLE;
  pNew->nTerm = 0;
  pNew->u.vtab.needFree = 0;
  pUsage = pIdxInfo->aConstraintUsage;

  for(iPhase=0; iPhase<=3; iPhase++){
    if( !seenIn && (iPhase&1)!=0 ){
      iPhase++;
      if( iPhase>3 ) break;
    }
    if( !seenVar && iPhase>1 ) break;
    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
    for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){

    pIdxInfo->orderByConsumed = 0;
    /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */
    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2);
    rc = vtabBestIndex(pParse, pTab, pIdxInfo);
    if( rc ) goto whereLoopAddVtab_exit;
    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
    pNew->prereq = 0;


    mxTerm = -1;
    for(i=0; i<pBuilder->mxTerm; i++) pNew->aTerm[i] = 0;
    for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
      if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){
        if( iTerm>=pBuilder->mxTerm ) break;
        j = pIdxCons->iTermOffset;
        if( iTerm>=pIdxInfo->nConstraint
         || j<0
         || j>=pWC->nTerm
         || pNew->aTerm[iTerm]!=0
        ){
          rc = SQLITE_ERROR;