SQLite

Check-in [ee30fb3521]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Avoid O(N*N) behavior with very long lists of VALUES.
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | many-VALUEs
Files: files | file ages | folders
SHA1: ee30fb35217f3429ee89aaad7c19f29710420e4c
User & Date: drh 2015-01-05 20:04:51.191
Context
2015-01-05
20:13
Enhance "INSERT INTO ... VALUES" so that the number of rows in the VALUES clause is not limited by SQLITE_LIMIT_COMPOUND_SELECT, and so that the stack depth is constant regardless of the number of rows in VALUES. (check-in: e1c4a359aa user: drh tags: trunk)
20:04
Avoid O(N*N) behavior with very long lists of VALUES. (Closed-Leaf check-in: ee30fb3521 user: drh tags: many-VALUEs)
19:16
Handle compound-select statements originating from VALUES clauses as a special case that does not use recursion. (check-in: 9ce9e43af3 user: drh tags: many-VALUEs)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/select.c.
4111
4112
4113
4114
4115
4116
4117

4118

4119
4120
4121
4122
4123
4124
4125
    return WRC_Abort;
  }
  if( NEVER(p->pSrc==0) || (selFlags & SF_Expanded)!=0 ){
    return WRC_Prune;
  }
  pTabList = p->pSrc;
  pEList = p->pEList;

  sqlite3WithPush(pParse, findRightmost(p)->pWith, 0);


  /* Make sure cursor numbers have been assigned to all entries in
  ** the FROM clause of the SELECT statement.
  */
  sqlite3SrcListAssignCursors(pParse, pTabList);

  /* Look up every table named in the FROM clause of the select.  If







>
|
>







4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
    return WRC_Abort;
  }
  if( NEVER(p->pSrc==0) || (selFlags & SF_Expanded)!=0 ){
    return WRC_Prune;
  }
  pTabList = p->pSrc;
  pEList = p->pEList;
  if( pWalker->xSelectCallback2==selectPopWith ){
    sqlite3WithPush(pParse, findRightmost(p)->pWith, 0);
  }

  /* Make sure cursor numbers have been assigned to all entries in
  ** the FROM clause of the SELECT statement.
  */
  sqlite3SrcListAssignCursors(pParse, pTabList);

  /* Look up every table named in the FROM clause of the select.  If
4402
4403
4404
4405
4406
4407
4408

4409

4410
4411
4412
4413
4414
4415
4416
  w.xExprCallback = exprWalkNoop;
  w.pParse = pParse;
  if( pParse->hasCompound ){
    w.xSelectCallback = convertCompoundSelectToSubquery;
    sqlite3WalkSelect(&w, pSelect);
  }
  w.xSelectCallback = selectExpander;

  w.xSelectCallback2 = selectPopWith;

  sqlite3WalkSelect(&w, pSelect);
}


#ifndef SQLITE_OMIT_SUBQUERY
/*
** This is a Walker.xSelectCallback callback for the sqlite3SelectTypeInfo()







>
|
>







4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
  w.xExprCallback = exprWalkNoop;
  w.pParse = pParse;
  if( pParse->hasCompound ){
    w.xSelectCallback = convertCompoundSelectToSubquery;
    sqlite3WalkSelect(&w, pSelect);
  }
  w.xSelectCallback = selectExpander;
  if( (pSelect->selFlags & SF_AllValues)==0 ){
    w.xSelectCallback2 = selectPopWith;
  }
  sqlite3WalkSelect(&w, pSelect);
}


#ifndef SQLITE_OMIT_SUBQUERY
/*
** This is a Walker.xSelectCallback callback for the sqlite3SelectTypeInfo()