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Overview
Comment:Optimization to sqlite3WhereExprUsage().
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SHA1: 95493058fcf40306727a281f21c5a2a0011b7d02
User & Date: drh 2016-08-10 20:02:21.519
Context
2016-08-11
01:24
Fix a harmless compiler warning in FTS5. (check-in: 2ea0c8b46e user: drh tags: trunk)
2016-08-10
20:02
Optimization to sqlite3WhereExprUsage(). (check-in: 95493058fc user: drh tags: trunk)
19:43
List of MATCH operator names in isMatchOfColumn() should be constant. (check-in: 7319d676aa user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/whereexpr.c.
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/*
** These routines walk (recursively) an expression tree and generate
** a bitmask indicating which tables are used in that expression
** tree.
*/
Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
  Bitmask mask = 0;
  if( p==0 ) return 0;
  if( p->op==TK_COLUMN ){
    mask = sqlite3WhereGetMask(pMaskSet, p->iTable);
    return mask;
  }

  mask = sqlite3WhereExprUsage(pMaskSet, p->pRight);
  if( p->pLeft ) mask |= sqlite3WhereExprUsage(pMaskSet, p->pLeft);
  if( ExprHasProperty(p, EP_xIsSelect) ){
    mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
  }else if( p->x.pList ){
    mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
  }
  return mask;








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/*
** These routines walk (recursively) an expression tree and generate
** a bitmask indicating which tables are used in that expression
** tree.
*/
Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
  Bitmask mask;
  if( p==0 ) return 0;
  if( p->op==TK_COLUMN ){
    mask = sqlite3WhereGetMask(pMaskSet, p->iTable);
    return mask;
  }
  assert( !ExprHasProperty(p, EP_TokenOnly) );
  mask = p->pRight ? sqlite3WhereExprUsage(pMaskSet, p->pRight) : 0;
  if( p->pLeft ) mask |= sqlite3WhereExprUsage(pMaskSet, p->pLeft);
  if( ExprHasProperty(p, EP_xIsSelect) ){
    mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
  }else if( p->x.pList ){
    mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
  }
  return mask;
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