SQLite

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is responsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.347 2008/12/28 20:47:03 drh Exp $
*/
#include "sqliteInt.h"

/*
** Trace output macros
*/
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)

  int regRowSet         /* Register hold RowSet if WHERE_FILL_ROWSET is set */
){
  int i;                     /* Loop counter */
  WhereInfo *pWInfo;         /* Will become the return value of this function */
  Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
  Bitmask notReady;          /* Cursors that are not yet positioned */
  WhereMaskSet *pMaskSet;    /* The expression mask set */
  //WhereClause wc;          /* The WHERE clause is divided into these terms */
  WhereClause *pWC;               /* Decomposition of the WHERE clause */
  struct SrcList_item *pTabItem;  /* A single entry from pTabList */
  WhereLevel *pLevel;             /* A single level in the pWInfo list */
  int iFrom;                      /* First unused FROM clause element */
  int andFlags;              /* AND-ed combination of all pWC->a[].wtFlags */
  sqlite3 *db;               /* Database connection */
  ExprList *pOrderBy = 0;