Improvements to the subquery ORDER BY decision algorithm. Fewer false-negatives.

FossilOrigin-Name: b82421e3f5811946e9d60b845fc882b6ea5c53c648695654c6900754427bf9bf

diff --git a/manifest b/manifest
index e19579238d5e25787138512b80708dba77a771ce..ce77ec785861c4a318e59849f1107df62f40c41e 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C If\sa\ssubquery\sis\smaterialized\sdue\sto\san\sORDER\sBY\sand\sthat\sordering\sis\suseful\nin\shelping\sto\ssatisfy\sthe\sORDER\sBY\sor\sGROUP\sBY\sin\sthe\sorder\squery\swithout\ndoing\san\sextra\ssort,\sthen\somit\sthe\sextra\ssort.
-D 2024-08-15T23:38:52.210
+C Improvements\sto\sthe\ssubquery\sORDER\sBY\sdecision\salgorithm.\sFewer\sfalse-negatives.
+D 2024-08-16T00:37:54.145
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -846,7 +846,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 887fc4ca3f020ebb2e376f222069570834ac63bf50111ef0cbf3ae417048ed89
 F src/wal.h ba252daaa94f889f4b2c17c027e823d9be47ce39da1d3799886bbd51f0490452
 F src/walker.c 7c7ea0115345851c3da4e04e2e239a29983b61fb5b038b94eede6aba462640e2
-F src/where.c c59dffd249e5daa335bc43c2b87ffacc25dce995e3600a2b7bcdbcc55a68c985
+F src/where.c c6b742473a627bb0ff2aa1f05f3daaa7fc974b05fe4f84ae8a2d07fd7b92393c
 F src/whereInt.h 6444b888ce395cb80511284b8a73b63472d34247fcb1b125ee06a54fa6ae878e
 F src/wherecode.c c9cac0b0b8e809c5e7e79d7796918907fb685ad99be2aaa9737f9787aa47349c
 F src/whereexpr.c 7d0d34b42b9edfd8e8ca66beb3a6ef63fe211c001af54caf2ccbcd989b783290
@@ -2204,11 +2204,8 @@ F vsixtest/vsixtest.tcl 6195aba1f12a5e10efc2b8c0009532167be5e301abe5b31385638080
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 96e6cfb211f7f1aab50f997f4bc61dfb9701beb720c59bc413a4285c1ae5e20d
-R cc9a8ceafd2a9a7a7cbd542af1820055
-T *branch * order-by-subquery
-T *sym-order-by-subquery *
-T -sym-trunk *
+P 2fbb4dc2327ee435cb2b7a4adcddf5a9cee6dff7de96e2ecb761166427b5ddea
+R 4f42ef8d0868b345800db6a42ea20509
 U drh
-Z 66dcbf2773ae39411ce78a1d9346e7ac
+Z a8bc8a8b808f8550328f0344d9e7735f
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index 8f936c703f88b3bd8460c35caff0fd03ff9c9464..95e076fb40e998934f199c47abd2463b2a10c362 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-2fbb4dc2327ee435cb2b7a4adcddf5a9cee6dff7de96e2ecb761166427b5ddea
+b82421e3f5811946e9d60b845fc882b6ea5c53c648695654c6900754427bf9bf

diff --git a/src/where.c b/src/where.c
index b119301e1303f5c74249639462ce749acecbf094..561091e0a027c006decf87e58654a5706b1299a2 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -4887,22 +4887,25 @@ static SQLITE_NOINLINE int wherePathMatchSubqueryOB(
     if( pOBExpr->op!=TK_COLUMN && pOBExpr->op!=TK_AGG_COLUMN ) break;
     if( pOBExpr->iTable!=iCur ) break;
     if( pOBExpr->iColumn!=pSubOB->a[j].u.x.iOrderByCol-1 ) break;
-    if( pSubOB->a[j].fg.sortFlags & KEYINFO_ORDER_BIGNULL ) break;
-    revIdx = pSubOB->a[j].fg.sortFlags & KEYINFO_ORDER_DESC;
-    if( wctrlFlags & WHERE_GROUPBY ){
-      /* Sort order does not matter for GROUP BY */
-    }else if( j>0 ){
-      if( (rev ^ revIdx) != (pOrderBy->a[i].fg.sortFlags&KEYINFO_ORDER_DESC) ){
+    if( (wctrlFlags & WHERE_GROUPBY)==0 ){
+      if( (pSubOB->a[j].fg.sortFlags & KEYINFO_ORDER_BIGNULL)
+          != (pOrderBy->a[j].fg.sortFlags & KEYINFO_ORDER_BIGNULL) ){
         break;
       }
-    }else{
-      rev = revIdx ^ (pOrderBy->a[i].fg.sortFlags & KEYINFO_ORDER_DESC);
-      if( rev ){
-        if( (pLoop->wsFlags & WHERE_COROUTINE)!=0 ){
-          /* Cannot run a co-routine in reverse order */
+      revIdx = pSubOB->a[j].fg.sortFlags & KEYINFO_ORDER_DESC;
+      if( j>0 ){
+        if( (rev ^ revIdx)!=(pOrderBy->a[i].fg.sortFlags&KEYINFO_ORDER_DESC) ){
           break;
         }
-        *pRevMask |= MASKBIT(iLoop);
+      }else{
+        rev = revIdx ^ (pOrderBy->a[i].fg.sortFlags & KEYINFO_ORDER_DESC);
+        if( rev ){
+          if( (pLoop->wsFlags & WHERE_COROUTINE)!=0 ){
+            /* Cannot run a co-routine in reverse order */
+            break;
+          }
+          *pRevMask |= MASKBIT(iLoop);
+        }
       }
     }
     *pOBSat |= MASKBIT(i);