From: drh <drh@noemail.net>
Date: Mon, 22 May 2017 00:45:15 +0000 (+0000)
Subject: When planning a query using sorting, resolve ties in the solver by selecting
X-Git-Tag: version-3.20.0~260
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=78436d4c668240e3eff4cadff7637f940ff98eca;p=thirdparty%2Fsqlite.git

When planning a query using sorting, resolve ties in the solver by selecting
loop plans with the smaller unsorted cost.

FossilOrigin-Name: f261678c90297f9767040c577796cc1d4db598aa44b0de6906cb73eaef377dee
---

diff --git a/manifest b/manifest
index cde84e2378..ec53ee7d2e 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Prevent\sa\spossible\sNULL\spointer\sdereference\sin\sthe\sOP_Found\sopcode\sthat\ncan\sfollow\san\sOOM\serror.\s\sProblem\sfound\sby\sOSS-Fuzz.
-D 2017-05-19T22:51:00.217
+C When\splanning\sa\squery\susing\ssorting,\sresolve\sties\sin\sthe\ssolver\sby\sselecting\nloop\splans\swith\sthe\ssmaller\sunsorted\scost.
+D 2017-05-22T00:45:15.475
 F Makefile.in 1cc758ce3374a32425e4d130c2fe7b026b20de5b8843243de75f087c0a2661fb
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 8eeb80162074004e906b53d7340a12a14c471a83743aab975947e95ce061efcc
@@ -484,7 +484,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 40c543f0a2195d1b0dc88ef12142bea690009344
 F src/wal.h 06b2a0b599cc0f53ea97f497cf8c6b758c999f71
 F src/walker.c b71a992b413b3a022572eccf29ef4b4890223791
-F src/where.c a354396efcd326340ce17ac0c8af52ca8188ce65e26fda30e5af286dfc2d59f8
+F src/where.c ba36d01178f5957523cc600b95173057ae9a13ab378b4fc6ab5e14776767057b
 F src/whereInt.h 2a4b634d63ce488b46d4b0da8f2eaa8f9aeab202bc25ef76f007de5e3fba1f20
 F src/wherecode.c 8ad48867660519e262a401720845dc76934f86f558ec9606335fafcd7a2554f8
 F src/whereexpr.c e913aaa7b73ffcce66abcea5f197e2c538d48b5df78d0b7bba8ff4d73cc2e745
@@ -1580,7 +1580,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 946b87a5282f00d8c532a51f4390e6de781b9a0d6626cb3c077c5622895dc540
-R 892c6abfc58a4043f0c864668f2509c6
+P c2de178fe7e2e4e0d764e7e6ac637cfc8c053580c43f7246318dafad2974de3c
+Q +962531e7c1f3ff604271ddf9f47b6234dfd47702ccf24849f55b80814e7be267
+R 0174bb863aa0f92aa80b928036d9451c
 U drh
-Z fe52b75d8efb4b802f93708f3666bfdc
+Z 7c43670f11f196aa8059f227597167dc
diff --git a/manifest.uuid b/manifest.uuid
index 661efa4e1c..c024a6aa34 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c2de178fe7e2e4e0d764e7e6ac637cfc8c053580c43f7246318dafad2974de3c
\ No newline at end of file
+f261678c90297f9767040c577796cc1d4db598aa44b0de6906cb73eaef377dee
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index 3224e081fa..ecac0b0f13 100644
--- a/src/where.c
+++ b/src/where.c
@@ -4003,8 +4003,8 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
             ** this candidate as not viable. */
 #ifdef WHERETRACE_ENABLED /* 0x4 */
             if( sqlite3WhereTrace&0x4 ){
-              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d order=%c\n",
-                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d,%3d order=%c\n",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
                   isOrdered>=0 ? isOrdered+'0' : '?');
             }
 #endif
@@ -4022,26 +4022,36 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
           pTo = &aTo[jj];
 #ifdef WHERETRACE_ENABLED /* 0x4 */
           if( sqlite3WhereTrace&0x4 ){
-            sqlite3DebugPrintf("New    %s cost=%-3d,%3d order=%c\n",
-                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+            sqlite3DebugPrintf("New    %s cost=%-3d,%3d,%3d order=%c\n",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
                 isOrdered>=0 ? isOrdered+'0' : '?');
           }
 #endif
         }else{
           /* Control reaches here if best-so-far path pTo=aTo[jj] covers the
-          ** same set of loops and has the sam isOrdered setting as the
+          ** same set of loops and has the same isOrdered setting as the
           ** candidate path.  Check to see if the candidate should replace
-          ** pTo or if the candidate should be skipped */
-          if( pTo->rCost<rCost || (pTo->rCost==rCost && pTo->nRow<=nOut) ){
+          ** pTo or if the candidate should be skipped.
+          ** 
+          ** The conditional is an expanded vector comparison equivalent to:
+          **   (pTo->rCost,pTo->nRow,pTo->rUnsorted) <= (rCost,nOut,rUnsorted)
+          */
+          if( pTo->rCost<rCost 
+           || (pTo->rCost==rCost
+               && (pTo->nRow<nOut
+                   || (pTo->nRow==nOut && pTo->rUnsorted<=rUnsorted)
+                  )
+              )
+          ){
 #ifdef WHERETRACE_ENABLED /* 0x4 */
             if( sqlite3WhereTrace&0x4 ){
               sqlite3DebugPrintf(
-                  "Skip   %s cost=%-3d,%3d order=%c",
-                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                  "Skip   %s cost=%-3d,%3d,%3d order=%c",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
                   isOrdered>=0 ? isOrdered+'0' : '?');
-              sqlite3DebugPrintf("   vs %s cost=%-3d,%d order=%c\n",
+              sqlite3DebugPrintf("   vs %s cost=%-3d,%3d,%3d order=%c\n",
                   wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
-                  pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+                  pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
             }
 #endif
             /* Discard the candidate path from further consideration */
@@ -4054,12 +4064,12 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
 #ifdef WHERETRACE_ENABLED /* 0x4 */
           if( sqlite3WhereTrace&0x4 ){
             sqlite3DebugPrintf(
-                "Update %s cost=%-3d,%3d order=%c",
-                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                "Update %s cost=%-3d,%3d,%3d order=%c",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
                 isOrdered>=0 ? isOrdered+'0' : '?');
-            sqlite3DebugPrintf("  was %s cost=%-3d,%3d order=%c\n",
+            sqlite3DebugPrintf("  was %s cost=%-3d,%3d,%3d order=%c\n",
                 wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
-                pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+                pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
           }
 #endif
         }