SQLite

  int i;
  struct SrcList_item *pItem;
  if( pList==0 ) return;
  for(pItem=pList->a, i=0; i<pList->nSrc; i++, pItem++){
    sqlite3DbFree(db, pItem->zDatabase);
    sqlite3DbFree(db, pItem->zName);
    sqlite3DbFree(db, pItem->zAlias);
    if( pItem->fg.isIndexedBy ) sqlite3DbFree(db, pItem->u1.zIndexedBy);
    if( pItem->fg.isTabFunc ) sqlite3ExprListDelete(db, pItem->u1.pFuncArg);
    sqlite3DeleteTable(db, pItem->pTab);
    sqlite3SelectDelete(db, pItem->pSelect);
    sqlite3ExprDelete(db, pItem->pOn);
    sqlite3IdListDelete(db, pItem->pUsing);
  }
  sqlite3DbFree(db, pList);
}

** Add an INDEXED BY or NOT INDEXED clause to the most recently added 
** element of the source-list passed as the second argument.
*/
void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pIndexedBy){
  assert( pIndexedBy!=0 );
  if( p && ALWAYS(p->nSrc>0) ){
    struct SrcList_item *pItem = &p->a[p->nSrc-1];
    assert( pItem->fg.notIndexed==0 );
    assert( pItem->fg.isIndexedBy==0 );
    assert( pItem->fg.isTabFunc==0 );
    if( pIndexedBy->n==1 && !pIndexedBy->z ){
      /* A "NOT INDEXED" clause was supplied. See parse.y 
      ** construct "indexed_opt" for details. */
      pItem->fg.notIndexed = 1;
    }else{
      pItem->u1.zIndexedBy = sqlite3NameFromToken(pParse->db, pIndexedBy);
      pItem->fg.isIndexedBy = (pItem->u1.zIndexedBy!=0);
    }
  }
}

/*
** When building up a FROM clause in the parser, the join operator
** is initially attached to the left operand.  But the code generator

** in p->a[0] and p->a[1], respectively.  The parser initially stores the
** operator with A.  This routine shifts that operator over to B.
*/
void sqlite3SrcListShiftJoinType(SrcList *p){
  if( p ){
    int i;
    for(i=p->nSrc-1; i>0; i--){
      p->a[i].fg.jointype = p->a[i-1].fg.jointype;
    }
    p->a[0].fg.jointype = 0;
  }
}

/*
** Begin a transaction
*/
void sqlite3BeginTransaction(Parse *pParse, int type){

    struct SrcList_item *pNewItem = &pNew->a[i];
    struct SrcList_item *pOldItem = &p->a[i];
    Table *pTab;
    pNewItem->pSchema = pOldItem->pSchema;
    pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
    pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
    pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
    pNewItem->fg = pOldItem->fg;
    pNewItem->iCursor = pOldItem->iCursor;
    pNewItem->addrFillSub = pOldItem->addrFillSub;
    pNewItem->regReturn = pOldItem->regReturn;
    if( pNewItem->fg.isIndexedBy ){


      pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
    }
    pNewItem->pIBIndex = pOldItem->pIBIndex;
    if( pNewItem->fg.isTabFunc ){
      pNewItem->u1.pFuncArg = 
          sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
    }
    pTab = pNewItem->pTab = pOldItem->pTab;
    if( pTab ){
      pTab->nRef++;
    }
    pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
    pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);
    pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);

}

// "seltablist" is a "Select Table List" - the content of the FROM clause
// in a SELECT statement.  "stl_prefix" is a prefix of this list.
//
stl_prefix(A) ::= seltablist(X) joinop(Y).    {
   A = X;
   if( ALWAYS(A && A->nSrc>0) ) A->a[A->nSrc-1].fg.jointype = (u8)Y;
}
stl_prefix(A) ::= .                           {A = 0;}
seltablist(A) ::= stl_prefix(X) nm(Y) dbnm(D) as(Z) indexed_opt(I)
                  on_opt(N) using_opt(U). {
  A = sqlite3SrcListAppendFromTerm(pParse,X,&Y,&D,&Z,0,N,U);
  sqlite3SrcListIndexedBy(pParse, A, &I);
}

        for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
          if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
            /* If there has been exactly one prior match and this match
            ** is for the right-hand table of a NATURAL JOIN or is in a 
            ** USING clause, then skip this match.
            */
            if( cnt==1 ){
              if( pItem->fg.jointype & JT_NATURAL ) continue;
              if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
            }
            cnt++;
            pMatch = pItem;
            /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
            pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
            break;
          }
        }
      }
      if( pMatch ){
        pExpr->iTable = pMatch->iCursor;
        pExpr->pTab = pMatch->pTab;
        /* RIGHT JOIN not (yet) supported */
        assert( (pMatch->fg.jointype & JT_RIGHT)==0 );
        if( (pMatch->fg.jointype & JT_LEFT)!=0 ){
          ExprSetProperty(pExpr, EP_CanBeNull);
        }
        pSchema = pExpr->pTab->pSchema;
      }
    } /* if( pSrcList ) */

#ifndef SQLITE_OMIT_TRIGGER

        int nRef = 0;             /* Refcount for pOuterNC and outer contexts */
        const char *zSavedContext = pParse->zAuthContext;

        /* Count the total number of references to pOuterNC and all of its
        ** parent contexts. After resolving references to expressions in
        ** pItem->pSelect, check if this value has changed. If so, then
        ** SELECT statement pItem->pSelect must be correlated. Set the
        ** pItem->fg.isCorrelated flag if this is the case. */
        for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef += pNC->nRef;

        if( pItem->zName ) pParse->zAuthContext = pItem->zName;
        sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC);
        pParse->zAuthContext = zSavedContext;
        if( pParse->nErr || db->mallocFailed ) return WRC_Abort;

        for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef -= pNC->nRef;
        assert( pItem->fg.isCorrelated==0 && nRef<=0 );
        pItem->fg.isCorrelated = (nRef!=0);
      }
    }
  
    /* Set up the local name-context to pass to sqlite3ResolveExprNames() to
    ** resolve the result-set expression list.
    */
    sNC.ncFlags = NC_AllowAgg;

  pRight = &pLeft[1];
  for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
    Table *pLeftTab = pLeft->pTab;
    Table *pRightTab = pRight->pTab;
    int isOuter;

    if( NEVER(pLeftTab==0 || pRightTab==0) ) continue;
    isOuter = (pRight->fg.jointype & JT_OUTER)!=0;

    /* When the NATURAL keyword is present, add WHERE clause terms for
    ** every column that the two tables have in common.
    */
    if( pRight->fg.jointype & JT_NATURAL ){
      if( pRight->pOn || pRight->pUsing ){
        sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
           "an ON or USING clause", 0);
        return 1;
      }
      for(j=0; j<pRightTab->nCol; j++){
        char *zName;   /* Name of column in the right table */

**
**   <recursive-table> AS (<setup-query> UNION [ALL] <recursive-query>)
**                         \___________/             \_______________/
**                           p->pPrior                      p
**
**
** There is exactly one reference to the recursive-table in the FROM clause
** of recursive-query, marked with the SrcList->a[].fg.isRecursive flag.
**
** The setup-query runs once to generate an initial set of rows that go
** into a Queue table.  Rows are extracted from the Queue table one by
** one.  Each row extracted from Queue is output to pDest.  Then the single
** extracted row (now in the iCurrent table) becomes the content of the
** recursive-table for a recursive-query run.  The output of the recursive-query
** is added back into the Queue table.  Then another row is extracted from Queue

  regOffset = p->iOffset;
  p->pLimit = p->pOffset = 0;
  p->iLimit = p->iOffset = 0;
  pOrderBy = p->pOrderBy;

  /* Locate the cursor number of the Current table */
  for(i=0; ALWAYS(i<pSrc->nSrc); i++){
    if( pSrc->a[i].fg.isRecursive ){
      iCurrent = pSrc->a[i].iCursor;
      break;
    }
  }

  /* Allocate cursors numbers for Queue and Distinct.  The cursor number for
  ** the Distinct table must be exactly one greater than Queue in order

  ** effectively converts the OUTER JOIN into an INNER JOIN.
  **
  ** THIS OVERRIDES OBSOLETE COMMENTS 1 AND 2 ABOVE:
  ** Ticket #3300 shows that flattening the right term of a LEFT JOIN
  ** is fraught with danger.  Best to avoid the whole thing.  If the
  ** subquery is the right term of a LEFT JOIN, then do not flatten.
  */
  if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
    return 0;
  }

  /* Restriction 17: If the sub-query is a compound SELECT, then it must
  ** use only the UNION ALL operator. And none of the simple select queries
  ** that make up the compound SELECT are allowed to be aggregate or distinct
  ** queries.

    u8 jointype = 0;
    pSubSrc = pSub->pSrc;     /* FROM clause of subquery */
    nSubSrc = pSubSrc->nSrc;  /* Number of terms in subquery FROM clause */
    pSrc = pParent->pSrc;     /* FROM clause of the outer query */

    if( pSrc ){
      assert( pParent==p );  /* First time through the loop */
      jointype = pSubitem->fg.jointype;
    }else{
      assert( pParent!=p );  /* 2nd and subsequent times through the loop */
      pSrc = pParent->pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
      if( pSrc==0 ){
        assert( db->mallocFailed );
        break;
      }

    ** outer query.
    */
    for(i=0; i<nSubSrc; i++){
      sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);
      pSrc->a[i+iFrom] = pSubSrc->a[i];
      memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
    }
    pSrc->a[iFrom].fg.jointype = jointype;
  
    /* Now begin substituting subquery result set expressions for 
    ** references to the iParent in the outer query.
    ** 
    ** Example:
    **
    **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;

** If the source-list item passed as an argument was augmented with an
** INDEXED BY clause, then try to locate the specified index. If there
** was such a clause and the named index cannot be found, return 
** SQLITE_ERROR and leave an error in pParse. Otherwise, populate 
** pFrom->pIndex and return SQLITE_OK.
*/
int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){
  if( pFrom->pTab && pFrom->fg.isIndexedBy ){
    Table *pTab = pFrom->pTab;
    char *zIndexedBy = pFrom->u1.zIndexedBy;
    Index *pIdx;
    for(pIdx=pTab->pIndex; 
        pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy); 
        pIdx=pIdx->pNext
    );
    if( !pIdx ){
      sqlite3ErrorMsg(pParse, "no such index: %s", zIndexedBy, 0);
      pParse->checkSchema = 1;
      return SQLITE_ERROR;
    }
    pFrom->pIBIndex = pIdx;
  }
  return SQLITE_OK;
}
/*
** Detect compound SELECT statements that use an ORDER BY clause with 
** an alternative collating sequence.
**

      for(i=0; i<pSrc->nSrc; i++){
        struct SrcList_item *pItem = &pSrc->a[i];
        if( pItem->zDatabase==0 
         && pItem->zName!=0 
         && 0==sqlite3StrICmp(pItem->zName, pCte->zName)
          ){
          pItem->pTab = pTab;
          pItem->fg.isRecursive = 1;
          pTab->nRef++;
          pSel->selFlags |= SF_Recursive;
        }
      }
    }

    /* Only one recursive reference is permitted. */ 

  /* Look up every table named in the FROM clause of the select.  If
  ** an entry of the FROM clause is a subquery instead of a table or view,
  ** then create a transient table structure to describe the subquery.
  */
  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
    Table *pTab;
    assert( pFrom->fg.isRecursive==0 || pFrom->pTab );
    if( pFrom->fg.isRecursive ) continue;
    if( pFrom->pTab!=0 ){
      /* This statement has already been prepared.  There is no need
      ** to go further. */
      assert( i==0 );
#ifndef SQLITE_OMIT_CTE
      selectPopWith(pWalker, p);
#endif

            if( IsHiddenColumn(&pTab->aCol[j]) ){
              assert(IsVirtual(pTab));
              continue;
            }
            tableSeen = 1;

            if( i>0 && zTName==0 ){
              if( (pFrom->fg.jointype & JT_NATURAL)!=0
                && tableAndColumnIndex(pTabList, i, zName, 0, 0)
              ){
                /* In a NATURAL join, omit the join columns from the 
                ** table to the right of the join */
                continue;
              }
              if( sqlite3IdListIndex(pFrom->pUsing, zName)>=0 ){

    /* Sometimes the code for a subquery will be generated more than
    ** once, if the subquery is part of the WHERE clause in a LEFT JOIN,
    ** for example.  In that case, do not regenerate the code to manifest
    ** a view or the co-routine to implement a view.  The first instance
    ** is sufficient, though the subroutine to manifest the view does need
    ** to be invoked again. */
    if( pItem->addrFillSub ){
      if( pItem->fg.viaCoroutine==0 ){
        sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
      }
      continue;
    }

    /* Increment Parse.nHeight by the height of the largest expression
    ** tree referred to by this, the parent select. The child select
    ** may contain expression trees of at most
    ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
    ** more conservative than necessary, but much easier than enforcing
    ** an exact limit.
    */
    pParse->nHeight += sqlite3SelectExprHeight(p);

    /* Make copies of constant WHERE-clause terms in the outer query down
    ** inside the subquery.  This can help the subquery to run more efficiently.
    */
    if( (pItem->fg.jointype & JT_OUTER)==0
     && pushDownWhereTerms(db, pSub, p->pWhere, pItem->iCursor)
    ){
#if SELECTTRACE_ENABLED
      if( sqlite3SelectTrace & 0x100 ){
        SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n"));
        sqlite3TreeViewSelect(0, p, 0);
      }

      sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
      VdbeComment((v, "%s", pItem->pTab->zName));
      pItem->addrFillSub = addrTop;
      sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
      sqlite3Select(pParse, pSub, &dest);
      pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
      pItem->fg.viaCoroutine = 1;
      pItem->regResult = dest.iSdst;
      sqlite3VdbeAddOp1(v, OP_EndCoroutine, pItem->regReturn);
      sqlite3VdbeJumpHere(v, addrTop-1);
      sqlite3ClearTempRegCache(pParse);
    }else{
      /* Generate a subroutine that will fill an ephemeral table with
      ** the content of this subquery.  pItem->addrFillSub will point
      ** to the address of the generated subroutine.  pItem->regReturn
      ** is a register allocated to hold the subroutine return address
      */
      int topAddr;
      int onceAddr = 0;
      int retAddr;
      assert( pItem->addrFillSub==0 );
      pItem->regReturn = ++pParse->nMem;
      topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
      pItem->addrFillSub = topAddr+1;
      if( pItem->fg.isCorrelated==0 ){
        /* If the subquery is not correlated and if we are not inside of
        ** a trigger, then we only need to compute the value of the subquery
        ** once. */
        onceAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
        VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
      }else{
        VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));

  u8 tabFlags;         /* Mask of TF_* values */
  u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
#ifndef SQLITE_OMIT_ALTERTABLE
  int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
  int nModuleArg;      /* Number of arguments to the module */
  char **azModuleArg;  /* 0: module 1: schema 2: vtab name 3...: args */
  VTable *pVTable;     /* List of VTable objects. */
#endif
  Trigger *pTrigger;   /* List of triggers stored in pSchema */
  Schema *pSchema;     /* Schema that contains this table */
  Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
};

    char *zName;      /* Name of the table */
    char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
    Table *pTab;      /* An SQL table corresponding to zName */
    Select *pSelect;  /* A SELECT statement used in place of a table name */
    int addrFillSub;  /* Address of subroutine to manifest a subquery */
    int regReturn;    /* Register holding return address of addrFillSub */
    int regResult;    /* Registers holding results of a co-routine */
    struct {
      u8 jointype;      /* Type of join between this able and the previous */
      unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
      unsigned isIndexedBy :1;   /* True if there is an INDEXED BY clause */
      unsigned isTabFunc :1;     /* True if table-valued-function syntax */
      unsigned isCorrelated :1;  /* True if sub-query is correlated */
      unsigned viaCoroutine :1;  /* Implemented as a co-routine */
      unsigned isRecursive :1;   /* True for recursive reference in WITH */
    } fg;
#ifndef SQLITE_OMIT_EXPLAIN
    u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
#endif
    int iCursor;      /* The VDBE cursor number used to access this table */
    Expr *pOn;        /* The ON clause of a join */
    IdList *pUsing;   /* The USING clause of a join */
    Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
    union {
      char *zIndexedBy;    /* Identifier from "INDEXED BY <zIndex>" clause */
      ExprList *pFuncArg;  /* Arguments to table-valued-function */
    } u1;
    Index *pIBIndex;  /* Index structure corresponding to u1.zIndexedBy */
  } a[1];             /* One entry for each identifier on the list */
};

/*
** Permitted values of the SrcList.a.jointype field
*/
#define JT_INNER     0x0001    /* Any kind of inner or cross join */

      }
      if( pItem->pTab ){
        sqlite3XPrintf(&x, 0, " tabname=%Q", pItem->pTab->zName);
      }
      if( pItem->zAlias ){
        sqlite3XPrintf(&x, 0, " (AS %s)", pItem->zAlias);
      }
      if( pItem->fg.jointype & JT_LEFT ){
        sqlite3XPrintf(&x, 0, " LEFT-JOIN");
      }
      sqlite3StrAccumFinish(&x);
      sqlite3TreeViewItem(pView, zLine, i<p->pSrc->nSrc-1); 
      if( pItem->pSelect ){
        sqlite3TreeViewSelect(pView, pItem->pSelect, 0);
      }

  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
  VdbeComment((v, "for %s", pTable->zName));

  /* Fill the automatic index with content */
  sqlite3ExprCachePush(pParse);
  pTabItem = &pWC->pWInfo->pTabList->a[pLevel->iFrom];
  if( pTabItem->fg.viaCoroutine ){
    int regYield = pTabItem->regReturn;
    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
    addrTop =  sqlite3VdbeAddOp1(v, OP_Yield, regYield);
    VdbeCoverage(v);
    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
  }else{
    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
  }
  if( pPartial ){
    iContinue = sqlite3VdbeMakeLabel(v);
    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
    pLoop->wsFlags |= WHERE_PARTIALIDX;
  }
  regRecord = sqlite3GetTempReg(pParse);
  sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
  if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
  if( pTabItem->fg.viaCoroutine ){
    translateColumnToCopy(v, addrTop, pLevel->iTabCur, pTabItem->regResult);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
    pTabItem->fg.viaCoroutine = 0;
  }else{
    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
  }
  sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
  sqlite3VdbeJumpHere(v, addrTop);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ExprCachePop(pParse);

  pNew = pBuilder->pNew;
  if( db->mallocFailed ) return SQLITE_NOMEM;

  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
  assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
  if( pNew->wsFlags & WHERE_BTM_LIMIT ){
    opMask = WO_LT|WO_LE;
  }else if( /*pProbe->tnum<=0 ||*/ (pSrc->fg.jointype & JT_LEFT)!=0 ){
    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE;
  }else{
    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE|WO_ISNULL|WO_IS;
  }
  if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);

  assert( pNew->u.btree.nEq<pProbe->nColumn );

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

  if( pSrc->pIBIndex ){
    /* An INDEXED BY clause specifies a particular index to use */
    pProbe = pSrc->pIBIndex;
  }else if( !HasRowid(pTab) ){
    pProbe = pTab->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
    ** fake index the first in a chain of Index objects with all of the real
    ** indices to follow */
    Index *pFirst;                  /* First of real indices on the table */
    memset(&sPk, 0, sizeof(Index));
    sPk.nKeyCol = 1;
    sPk.nColumn = 1;
    sPk.aiColumn = &aiColumnPk;
    sPk.aiRowLogEst = aiRowEstPk;
    sPk.onError = OE_Replace;
    sPk.pTable = pTab;
    sPk.szIdxRow = pTab->szTabRow;
    aiRowEstPk[0] = pTab->nRowLogEst;
    aiRowEstPk[1] = 0;
    pFirst = pSrc->pTab->pIndex;
    if( pSrc->fg.notIndexed==0 ){
      /* The real indices of the table are only considered if the
      ** NOT INDEXED qualifier is omitted from the FROM clause */
      sPk.pNext = pFirst;
    }
    pProbe = &sPk;
  }
  rSize = pTab->nRowLogEst;
  rLogSize = estLog(rSize);

#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
  /* Automatic indexes */
  if( !pBuilder->pOrSet      /* Not part of an OR optimization */
   && (pWInfo->wctrlFlags & WHERE_NO_AUTOINDEX)==0
   && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
   && pSrc->pIBIndex==0      /* Has no INDEXED BY clause */
   && !pSrc->fg.notIndexed   /* Has no NOT INDEXED clause */
   && HasRowid(pTab)         /* Is not a WITHOUT ROWID table. (FIXME: Why not?) */
   && !pSrc->fg.isCorrelated /* Not a correlated subquery */
   && !pSrc->fg.isRecursive  /* Not a recursive common table expression. */
  ){
    /* Generate auto-index WhereLoops */
    WhereTerm *pTerm;
    WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
    for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
      if( pTerm->prereqRight & pNew->maskSelf ) continue;
      if( termCanDriveIndex(pTerm, pSrc, 0) ){

    sqlite3Stat4ProbeFree(pBuilder->pRec);
    pBuilder->nRecValid = 0;
    pBuilder->pRec = 0;
#endif

    /* If there was an INDEXED BY clause, then only that one index is
    ** considered. */
    if( pSrc->pIBIndex ) break;
  }
  return rc;
}

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Add all WhereLoop objects for a table of the join identified by

  /* Loop over the tables in the join, from left to right */
  pNew = pBuilder->pNew;
  whereLoopInit(pNew);
  for(iTab=0, pItem=pTabList->a; pItem<pEnd; iTab++, pItem++){
    Bitmask mUnusable = 0;
    pNew->iTab = iTab;
    pNew->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, pItem->iCursor);
    if( ((pItem->fg.jointype|priorJointype) & (JT_LEFT|JT_CROSS))!=0 ){
      /* This condition is true when pItem is the FROM clause term on the
      ** right-hand-side of a LEFT or CROSS JOIN.  */
      mExtra = mPrior;
    }
    priorJointype = pItem->fg.jointype;
    if( IsVirtual(pItem->pTab) ){
      struct SrcList_item *p;
      for(p=&pItem[1]; p<pEnd; p++){
        if( mUnusable || (p->fg.jointype & (JT_LEFT|JT_CROSS)) ){
          mUnusable |= sqlite3WhereGetMask(&pWInfo->sMaskSet, p->iCursor);
        }
      }
      rc = whereLoopAddVirtual(pBuilder, mExtra, mUnusable);
    }else{
      rc = whereLoopAddBtree(pBuilder, mExtra);
    }

  
  pWInfo = pBuilder->pWInfo;
  if( pWInfo->wctrlFlags & WHERE_FORCE_TABLE ) return 0;
  assert( pWInfo->pTabList->nSrc>=1 );
  pItem = pWInfo->pTabList->a;
  pTab = pItem->pTab;
  if( IsVirtual(pTab) ) return 0;
  if( pItem->fg.isIndexedBy ) return 0;
  iCur = pItem->iCursor;
  pWC = &pWInfo->sWC;
  pLoop = pBuilder->pNew;
  pLoop->wsFlags = 0;
  pLoop->nSkip = 0;
  pTerm = sqlite3WhereFindTerm(pWC, iCur, -1, 0, WO_EQ|WO_IS, 0);
  if( pTerm ){

    Bitmask tabUsed = sqlite3WhereExprListUsage(pMaskSet, pResultSet);
    if( sWLB.pOrderBy ){
      tabUsed |= sqlite3WhereExprListUsage(pMaskSet, sWLB.pOrderBy);
    }
    while( pWInfo->nLevel>=2 ){
      WhereTerm *pTerm, *pEnd;
      pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
      if( (pWInfo->pTabList->a[pLoop->iTab].fg.jointype & JT_LEFT)==0 ) break;
      if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
       && (pLoop->wsFlags & WHERE_ONEROW)==0
      ){
        break;
      }
      if( (tabUsed & pLoop->maskSelf)!=0 ) break;
      pEnd = sWLB.pWC->a + sWLB.pWC->nTerm;

    assert( pTab!=0 );
    pLoop = pLevel->pWLoop;

    /* For a co-routine, change all OP_Column references to the table of
    ** the co-routine into OP_Copy of result contained in a register.
    ** OP_Rowid becomes OP_Null.
    */
    if( pTabItem->fg.viaCoroutine && !db->mallocFailed ){
      translateColumnToCopy(v, pLevel->addrBody, pLevel->iTabCur,
                            pTabItem->regResult);
      continue;
    }

    /* Close all of the cursors that were opened by sqlite3WhereBegin.
    ** Except, do not close cursors that will be reused by the OR optimization

  addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
  addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);

  /* If this is the right table of a LEFT OUTER JOIN, allocate and
  ** initialize a memory cell that records if this table matches any
  ** row of the left table of the join.
  */
  if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
    pLevel->iLeftJoin = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
    VdbeComment((v, "init LEFT JOIN no-match flag"));
  }

  /* Special case of a FROM clause subquery implemented as a co-routine */
  if( pTabItem->fg.viaCoroutine ){
    int regYield = pTabItem->regReturn;
    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
    pLevel->p2 =  sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
    VdbeCoverage(v);
    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
    pLevel->op = OP_Goto;
  }else

  {
    /* Case 6:  There is no usable index.  We must do a complete
    **          scan of the entire table.
    */
    static const u8 aStep[] = { OP_Next, OP_Prev };
    static const u8 aStart[] = { OP_Rewind, OP_Last };
    assert( bRev==0 || bRev==1 );
    if( pTabItem->fg.isRecursive ){
      /* Tables marked isRecursive have only a single row that is stored in
      ** a pseudo-cursor.  No need to Rewind or Next such cursors. */
      pLevel->op = OP_Noop;
    }else{
      pLevel->op = aStep[bRev];
      pLevel->p1 = iCur;
      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);

  SELECT *, '|' FROM generate_series WHERE start=1 AND stop=9 AND step=2;
} {1 | 3 | 5 | 7 | 9 |}
do_execsql_test tabfunc01-1.2 {
  SELECT *, '|' FROM generate_series LIMIT 5;
} {0 | 1 | 2 | 3 | 4 |}
do_catchsql_test tabfunc01-1.3 {
  CREATE VIRTUAL TABLE t1 USING generate_series;
} {1 {no such module: generate_series}}

finish_test