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Changes to src/expr.c.

  1564   1564     if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
  1565   1565     if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
  1566   1566     if( sqlite3StrICmp(z, "OID")==0 ) return 1;
  1567   1567     return 0;
  1568   1568   }
  1569   1569   
  1570   1570   /*
  1571         -** Return true if we are able to the IN operator optimization on a
  1572         -** query of the form
  1573         -**
  1574         -**       x IN (SELECT ...)
  1575         -**
  1576         -** Where the SELECT... clause is as specified by the parameter to this
  1577         -** routine.
  1578         -**
  1579         -** The Select object passed in has already been preprocessed and no
  1580         -** errors have been found.
         1571  +** pX is the RHS of an IN operator.  If pX is a SELECT statement 
         1572  +** that can be simplified to a direct table access, then return
         1573  +** a pointer to the SELECT statement.  If pX is not a SELECT statement,
         1574  +** or if the SELECT statement needs to be manifested into a transient
         1575  +** table, then return NULL.
  1581   1576   */
  1582   1577   #ifndef SQLITE_OMIT_SUBQUERY
  1583         -static int isCandidateForInOpt(Select *p){
         1578  +static Select *isCandidateForInOpt(Expr *pX){
         1579  +  Select *p;
  1584   1580     SrcList *pSrc;
  1585   1581     ExprList *pEList;
         1582  +  Expr *pRes;
  1586   1583     Table *pTab;
  1587         -  Expr *pRes;                            /* Result expression */
  1588         -  if( p==0 ) return 0;                   /* right-hand side of IN is SELECT */
         1584  +  if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0;  /* Not a subquery */
         1585  +  if( ExprHasProperty(pX, EP_VarSelect)  ) return 0;  /* Correlated subq */
         1586  +  p = pX->x.pSelect;
  1589   1587     if( p->pPrior ) return 0;              /* Not a compound SELECT */
  1590   1588     if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
  1591   1589       testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
  1592   1590       testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
  1593   1591       return 0; /* No DISTINCT keyword and no aggregate functions */
  1594   1592     }
  1595   1593     assert( p->pGroupBy==0 );              /* Has no GROUP BY clause */
................................................................................
  1597   1595     assert( p->pOffset==0 );               /* No LIMIT means no OFFSET */
  1598   1596     if( p->pWhere ) return 0;              /* Has no WHERE clause */
  1599   1597     pSrc = p->pSrc;
  1600   1598     assert( pSrc!=0 );
  1601   1599     if( pSrc->nSrc!=1 ) return 0;          /* Single term in FROM clause */
  1602   1600     if( pSrc->a[0].pSelect ) return 0;     /* FROM is not a subquery or view */
  1603   1601     pTab = pSrc->a[0].pTab;
  1604         -  if( NEVER(pTab==0) ) return 0;
         1602  +  assert( pTab!=0 );
  1605   1603     assert( pTab->pSelect==0 );            /* FROM clause is not a view */
  1606   1604     if( IsVirtual(pTab) ) return 0;        /* FROM clause not a virtual table */
  1607   1605     pEList = p->pEList;
  1608   1606     if( pEList->nExpr!=1 ) return 0;       /* One column in the result set */
  1609   1607     pRes = pEList->a[0].pExpr;
  1610   1608     if( pRes->op!=TK_COLUMN ) return 0;    /* Result is a column */
  1611         -  if( pRes->iTable!=pSrc->a[0].iCursor ) return 0;  /* Not a correlated subq */
  1612         -  return 1;
         1609  +  assert( pRes->iTable==pSrc->a[0].iCursor );  /* Not a correlated subquery */
         1610  +  return p;
  1613   1611   }
  1614   1612   #endif /* SQLITE_OMIT_SUBQUERY */
  1615   1613   
  1616   1614   /*
  1617   1615   ** Code an OP_Once instruction and allocate space for its flag. Return the 
  1618   1616   ** address of the new instruction.
  1619   1617   */
................................................................................
  1737   1735     assert( pX->op==TK_IN );
  1738   1736     mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
  1739   1737   
  1740   1738     /* Check to see if an existing table or index can be used to
  1741   1739     ** satisfy the query.  This is preferable to generating a new 
  1742   1740     ** ephemeral table.
  1743   1741     */
  1744         -  p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
  1745         -  if( pParse->nErr==0 && isCandidateForInOpt(p) ){
         1742  +  if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){
  1746   1743       sqlite3 *db = pParse->db;              /* Database connection */
  1747   1744       Table *pTab;                           /* Table <table>. */
  1748   1745       Expr *pExpr;                           /* Expression <column> */
  1749   1746       i16 iCol;                              /* Index of column <column> */
  1750   1747       i16 iDb;                               /* Database idx for pTab */
  1751   1748   
  1752         -    assert( p );                        /* Because of isCandidateForInOpt(p) */
  1753   1749       assert( p->pEList!=0 );             /* Because of isCandidateForInOpt(p) */
  1754   1750       assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
  1755   1751       assert( p->pSrc!=0 );               /* Because of isCandidateForInOpt(p) */
  1756   1752       pTab = p->pSrc->a[0].pTab;
  1757   1753       pExpr = p->pEList->a[0].pExpr;
  1758   1754       iCol = (i16)pExpr->iColumn;
  1759   1755