From: drh <drh@noemail.net>
Date: Tue, 20 Mar 2018 18:08:33 +0000 (+0000)
Subject: Improvements to the HAVING-to-WHERE optimization.  The code uses less space
X-Git-Tag: version-3.23.0~44
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cd0abc24d13a437aa3133e2e45f0cc1f362b01dc;p=thirdparty%2Fsqlite.git

Improvements to the HAVING-to-WHERE optimization.  The code uses less space
and less CPU, and there is now ".selecttrace" output.

FossilOrigin-Name: 5ad668d4339397fe66fe085e0527e37a1930917da88d462a8d89a465faa15e28
---

diff --git a/manifest b/manifest
index 2dc3feea2e..3272cab2e2 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C For\s'zipfile',\sdetect\sattempts\sto\scause\sa\sduplicate\sentry\svia\sUPDATE.\s\sAlso,\sfix\shandling\sof\s'UPDATE\sOR\sREPLACE'\sstatements\srun\son\szipfile\svirtual\stables.\s\sWin32\sportability\sfixes\sto\sthe\s'fileio'\sextension.\s\sMiscellaneous\stest\sfixes.
-D 2018-03-20T16:56:12.064
+C Improvements\sto\sthe\sHAVING-to-WHERE\soptimization.\s\sThe\scode\suses\sless\sspace\nand\sless\sCPU,\sand\sthere\sis\snow\s".selecttrace"\soutput.
+D 2018-03-20T18:08:33.634
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 7016fc56c6b9bfe5daac4f34be8be38d8c0b5fab79ccbfb764d3b23bf1c6fff3
@@ -489,12 +489,12 @@ F src/printf.c d3b7844ddeb11fbbdd38dd84d09c9c1ac171d21fb038473c3aa97981201cc660
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 66c73fcb7719b8ff0e841b58338f13604ff3e2b50a723f9b8f383595735262f6
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
-F src/select.c 97a2131f02c605c52a6d5deac5b2ae6604db8c346829eb6b185bc38512a9b49a
+F src/select.c 69ed6ca9d1bf4adb41472b0740b7b90868438dedcdd5ab2fd608070eca30d073
 F src/shell.c.in 911b9e3bce40413c78fdba28efa28363e98183819bd4b300780bf57bacfc4b84
 F src/sqlite.h.in 19762b57baa1ade67531f254de94374428fb9c82452ef305017847945f9c2911
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 83a3c4ce93d650bedfd1aa558cb85a516bd6d094445ee989740827d0d944368d
-F src/sqliteInt.h 5c07bbc55d9eb3389a10536bd008e2d6f20f586871972610431d943595b40ca4
+F src/sqliteInt.h 7e9deb145c110289f50fcf72a8742d030834885676482391fe83c3cee75f97d4
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -1712,8 +1712,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P ec7addc87f97bcff3c3694b14a680453b52de3f8c106436f0708a1cc04b90faa 9a5ef341de2bd2fc4657a510f48159f7876f58d340b457b4272a71d389f88da3
-R 1e4df846035bbcb340ca288f329df6a5
-T +closed 9a5ef341de2bd2fc4657a510f48159f7876f58d340b457b4272a71d389f88da3
-U mistachkin
-Z 2140b1494b49e09f4697bfddad075bea
+P b36caeca91647616ac2ccdb281200c1a8bcd15d1f30dda0c1d89440d54607196
+R 8c8ba3697adfaee222e4b3bf5fcfea0c
+U drh
+Z 2c3bb9ba5e9ef9c236ac01dacb11a7b0
diff --git a/manifest.uuid b/manifest.uuid
index 1262402dd1..a89f26e2b2 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-b36caeca91647616ac2ccdb281200c1a8bcd15d1f30dda0c1d89440d54607196
\ No newline at end of file
+5ad668d4339397fe66fe085e0527e37a1930917da88d462a8d89a465faa15e28
\ No newline at end of file
diff --git a/src/select.c b/src/select.c
index 5b60fc6a67..ded01807ed 100644
--- a/src/select.c
+++ b/src/select.c
@@ -4912,14 +4912,6 @@ static void explainSimpleCount(
 # define explainSimpleCount(a,b,c)
 #endif
 
-/*
-** Context object for havingToWhereExprCb().
-*/
-struct HavingToWhereCtx {
-  Expr **ppWhere;
-  ExprList *pGroupBy;
-};
-
 /*
 ** sqlite3WalkExpr() callback used by havingToWhere().
 **
@@ -4933,15 +4925,16 @@ struct HavingToWhereCtx {
 */
 static int havingToWhereExprCb(Walker *pWalker, Expr *pExpr){
   if( pExpr->op!=TK_AND ){
-    struct HavingToWhereCtx *p = pWalker->u.pHavingCtx;
-    if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, p->pGroupBy) ){
+    Select *pS = pWalker->u.pSelect;
+    if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, pS->pGroupBy) ){
       sqlite3 *db = pWalker->pParse->db;
       Expr *pNew = sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[1], 0);
       if( pNew ){
-        Expr *pWhere = *(p->ppWhere);
+        Expr *pWhere = pS->pWhere;
         SWAP(Expr, *pNew, *pExpr);
         pNew = sqlite3ExprAnd(db, pWhere, pNew);
-        *(p->ppWhere) = pNew;
+        pS->pWhere = pNew;
+        pWalker->eCode = 1;
       }
     }
     return WRC_Prune;
@@ -4964,23 +4957,19 @@ static int havingToWhereExprCb(Walker *pWalker, Expr *pExpr){
 ** entirely of constants and expressions that are also GROUP BY terms that
 ** use the "BINARY" collation sequence.
 */
-static void havingToWhere(
-  Parse *pParse,
-  ExprList *pGroupBy,
-  Expr *pHaving, 
-  Expr **ppWhere
-){
-  struct HavingToWhereCtx sCtx;
+static void havingToWhere(Parse *pParse, Select *p){
   Walker sWalker;
-
-  sCtx.ppWhere = ppWhere;
-  sCtx.pGroupBy = pGroupBy;
-
   memset(&sWalker, 0, sizeof(sWalker));
   sWalker.pParse = pParse;
   sWalker.xExprCallback = havingToWhereExprCb;
-  sWalker.u.pHavingCtx = &sCtx;
-  sqlite3WalkExpr(&sWalker, pHaving);
+  sWalker.u.pSelect = p;
+  sqlite3WalkExpr(&sWalker, p->pHaving);
+#if SELECTTRACE_ENABLED
+  if( sWalker.eCode && (sqlite3SelectTrace & 0x100)!=0 ){
+    SELECTTRACE(0x100,pParse,p,("Move HAVING terms into WHERE:\n"));
+    sqlite3TreeViewSelect(0, p, 0);
+  }
+#endif
 }
 
 /*
@@ -5649,7 +5638,9 @@ int sqlite3Select(
     if( pHaving ){
       if( pGroupBy ){
         assert( pWhere==p->pWhere );
-        havingToWhere(pParse, pGroupBy, pHaving, &p->pWhere);
+        assert( pHaving==p->pHaving );
+        assert( pGroupBy==p->pGroupBy );
+        havingToWhere(pParse, p);
         pWhere = p->pWhere;
       }
       sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 038fd5da88..7c8cf121f4 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3357,9 +3357,9 @@ struct Walker {
     struct CCurHint *pCCurHint;               /* Used by codeCursorHint() */
     int *aiCol;                               /* array of column indexes */
     struct IdxCover *pIdxCover;               /* Check for index coverage */
-    struct IdxExprTrans *pIdxTrans;           /* Convert indexed expr to column */
+    struct IdxExprTrans *pIdxTrans;           /* Convert idxed expr to column */
     ExprList *pGroupBy;                       /* GROUP BY clause */
-    struct HavingToWhereCtx *pHavingCtx;      /* HAVING to WHERE clause ctx */
+    Select *pSelect;                          /* HAVING to WHERE clause ctx */
   } u;
 };