From: drh <>
Date: Fri, 22 Aug 2025 16:34:55 +0000 (+0000)
Subject: Experimental minor simplification of the query flattener.
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fheads%2Fsimplify-flattener;p=thirdparty%2Fsqlite.git

Experimental minor simplification of the query flattener.

FossilOrigin-Name: 953ea637d51192a6fb9c2ae84e097ae14e8a9c7fa7c98db90a39819b5f97f60e
---

diff --git a/manifest b/manifest
index 73c5ed4732..084f2b2f17 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\sminor\stypo\sin\sa\scomment.
-D 2025-08-21T18:47:01.547
+C Experimental\sminor\ssimplification\sof\sthe\squery\sflattener.
+D 2025-08-22T16:34:55.559
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -741,7 +741,7 @@ F src/printf.c 5f0c957af9699e849d786e8fbaa3baab648ca5612230dc17916434c14bc8698f
 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
 F src/resolve.c f8d1d011aba0964ff1bdccd049d4d2c2fec217efd90d202a4bb775e926b2c25d
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
-F src/select.c 78ebf432355e820962a5001277cb43ffe3d82441c6dc9c8f0aeb0b15fbd5dd02
+F src/select.c 68b8a11c81ddf1e74f85350d4766c3ac454be22bbf9df8b06293328e47760809
 F src/shell.c.in 0636915df0dbac6c780f04959f5d1055f206fb281b2c8fc8b113fe7bfc7d44ef
 F src/sqlite.h.in ebfc0358de0e18aabee7fa918f2f846894e23bebc74160fbe265c99046ee61b8
 F src/sqlite3.rc 015537e6ac1eec6c7050e17b616c2ffe6f70fca241835a84a4f0d5937383c479
@@ -2169,8 +2169,11 @@ F tool/version-info.c 3b36468a90faf1bbd59c65fd0eb66522d9f941eedd364fabccd7227350
 F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee87c1b31a7
 F tool/warnings.sh 1ad0169b022b280bcaaf94a7fa231591be96b514230ab5c98fbf15cd7df842dd
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 9f15182776b30676c9aae9bcb5d4ad7580359fbdd607c2a9227c9cf2c81a4054
-R e87d0e2ec7db35078d5f7c68106ae850
+P 9ada44eb6d26532e45cdd2ed8d5707f1734d0177a13b493ff9cf070e0a992522
+R 18f04a3f1190add04a7dcfda2fc1cbb0
+T *branch * simplify-flattener
+T *sym-simplify-flattener *
+T -sym-trunk *
 U drh
-Z a3b0bda8d54e990d1d0f3efd38f275ec
+Z 80d8e3061b1db9479a1cf58c856482da
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 565294e9a4..3f16570aaa 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9ada44eb6d26532e45cdd2ed8d5707f1734d0177a13b493ff9cf070e0a992522
+953ea637d51192a6fb9c2ae84e097ae14e8a9c7fa7c98db90a39819b5f97f60e
diff --git a/src/select.c b/src/select.c
index 8bdd13e272..b0fa0f4a5a 100644
--- a/src/select.c
+++ b/src/select.c
@@ -4706,17 +4706,12 @@ static int flattenSubquery(
   pSub = pSub1;
   for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){
     int nSubSrc;
-    u8 jointype = 0;
-    u8 ltorj = pSrc->a[iFrom].fg.jointype & JT_LTORJ;
+    u8 jointype = pSubitem->fg.jointype;
     assert( pSub!=0 );
     pSubSrc = pSub->pSrc;     /* FROM clause of subquery */
     nSubSrc = pSubSrc->nSrc;  /* Number of terms in subquery FROM clause */
     pSrc = pParent->pSrc;     /* FROM clause of the outer query */
 
-    if( pParent==p ){
-      jointype = pSubitem->fg.jointype;     /* First time through the loop */
-    }
-   
     /* The subquery uses a single slot of the FROM clause of the outer
     ** query.  If the subquery has more than one element in its FROM clause,
     ** then expand the outer query to make space for it to hold all elements
@@ -4736,6 +4731,7 @@ static int flattenSubquery(
       pSrc = sqlite3SrcListEnlarge(pParse, pSrc, nSubSrc-1,iFrom+1);
       if( pSrc==0 ) break;
       pParent->pSrc = pSrc;
+      pSubitem = &pSrc->a[iFrom];
     }
 
     /* Transfer the FROM clause terms from the subquery into the
@@ -4750,11 +4746,10 @@ static int flattenSubquery(
            || pItem->u4.zDatabase==0 );
       if( pItem->fg.isUsing ) sqlite3IdListDelete(db, pItem->u3.pUsing);
       *pItem = pSubSrc->a[i];
-      pItem->fg.jointype |= ltorj;
+      pItem->fg.jointype |= (jointype & JT_LTORJ);
       memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
     }
-    pSrc->a[iFrom].fg.jointype &= JT_LTORJ;
-    pSrc->a[iFrom].fg.jointype |= jointype | ltorj;
+    pSubitem->fg.jointype |= jointype;
  
     /* Now begin substituting subquery result set expressions for
     ** references to the iParent in the outer query.