SQLite

** Duplicate ephemeral cursors are used for self-joins of materialized views.
*/
case OP_OpenDup: {
  VdbeCursor *pOrig;    /* The original cursor to be duplicated */
  VdbeCursor *pCx;      /* The new cursor */

  pOrig = p->apCsr[pOp->p2];

  assert( pOrig->pBtx!=0 );  /* Only ephemeral cursors can be duplicated */

  pCx = allocateCursor(p, pOp->p1, pOrig->nField, -1, CURTYPE_BTREE);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  pCx->isEphemeral = 1;
  pCx->pKeyInfo = pOrig->pKeyInfo;

  Parse *pParse,        /* The parsing context */
  int iEq,              /* Look at loop terms starting here */
  WhereLoop *pLoop,     /* The current loop */
  Expr *pX              /* The IN expression to be reduced */
){
  sqlite3 *db = pParse->db;
  Expr *pNew;
#ifndef SQLITE_OMIT_WINDOWFUNC
  /* The SELECT statement at pX->x.pSelect has already been resolved. This
  ** means that its window functions have already been identified and 
  ** linked into the Select.pWin list. However, if there are multiple 
  ** window functions and they do not all use the same window frame, only
  ** those that use the same window frame as the first resolved are listed
  ** in Select.pWin. Any others are delegated to sub-selects created by the 
  ** call to sqlite3WindowRewrite() made when coding the SELECT statement.
  ** But - sqlite3WindowRewrite() is a no-op if Select.pWin==0. And if 
  ** removing the unindexable terms happens to remove all window functions
  ** in the Select.pWin list, then Select.pWin ends up set to NULL - meaning
  ** that the other window functions are never processed. To work around
  ** this, ensure that sqlite3WindowRewrite() has been called to create the
  ** required sub-selects before the unindexable terms are removed. See
  ** ticket #f00d096ca.  */
  if( sqlite3WindowRewrite(pParse, pX->x.pSelect) ) return 0;
#endif
  pNew = sqlite3ExprDup(db, pX, 0);
  if( db->mallocFailed==0 ){
    ExprList *pOrigRhs = pNew->x.pSelect->pEList;  /* Original unmodified RHS */
    ExprList *pOrigLhs = pNew->pLeft->x.pList;     /* Original unmodified LHS */
    ExprList *pRhs = 0;         /* New RHS after modifications */
    ExprList *pLhs = 0;         /* New LHS after mods */
    int i;                      /* Loop counter */

  /* If there is a vector IN term - e.g. "(a, b) IN (SELECT ...)" - create
  ** a virtual term for each vector component. The expression object
  ** used by each such virtual term is pExpr (the full vector IN(...) 
  ** expression). The WhereTerm.iField variable identifies the index within
  ** the vector on the LHS that the virtual term represents.
  **
  ** This only works if the RHS is a simple SELECT, not a compound

  */
  if( pWC->op==TK_AND && pExpr->op==TK_IN && pTerm->iField==0
   && pExpr->pLeft->op==TK_VECTOR
   && pExpr->x.pSelect->pPrior==0



  ){
    int i;
    for(i=0; i<sqlite3ExprVectorSize(pExpr->pLeft); i++){
      int idxNew;
      idxNew = whereClauseInsert(pWC, pExpr, TERM_VIRTUAL);
      pWC->a[idxNew].iField = i+1;
      exprAnalyze(pSrc, pWC, idxNew);

} {0}
do_execsql_test 38.20 {
  SELECT COUNT(*), AVG(1) FILTER(WHERE t1.c1) FROM t0, t1;
} {1 1.0}
do_execsql_test 38.30 {
  SELECT COUNT(*) FROM t0, t1 WHERE (SELECT AVG(1) FILTER(WHERE t1.c1));
} {1}












finish_test