From: drh <>
Date: Tue, 7 Dec 2021 22:37:50 +0000 (+0000)
Subject: Do not generate a Bloom filter if it cannot be used prior to the next seek,
X-Git-Tag: version-3.38.0~186^2~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=761d64b73bc7ceb5ef60d956b6e1b78c1997082d;p=thirdparty%2Fsqlite.git

Do not generate a Bloom filter if it cannot be used prior to the next seek,
as that leads to a misleading EXPLAIN QUERY PLAN.

FossilOrigin-Name: 2739ed5192058fbcc816ecbc252be687efc606e038bfcd6cf71194a3f4f5684e
---

diff --git a/manifest b/manifest
index 6a4298ce44..78850cff06 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Improved\sEXPLAIN\sQUERY\sPLAN\soutput\sfor\sBloom\sfilters.
-D 2021-12-06T23:07:59.482
+C Do\snot\sgenerate\sa\sBloom\sfilter\sif\sit\scannot\sbe\sused\sprior\sto\sthe\snext\sseek,\nas\sthat\sleads\sto\sa\smisleading\sEXPLAIN\sQUERY\sPLAN.
+D 2021-12-07T22:37:50.686
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -638,7 +638,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c ed0398a7adf02c31e34aada42cc86c58f413a7afe5f741a5d373ad087abde028
 F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
 F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c 21bd1078837afb127827243d7ad549a4b47022ffaa43c5baa74dcac7f89809a7
+F src/where.c 328e5c6f5a91f8c1e36417159cc93ea180700ae97726f934f69e68c8c60030b5
 F src/whereInt.h 5c6601d6d0b7b8936482506d2d835981cc6efcd8e106a829893a27a14cfb10b8
 F src/wherecode.c f82a322a8849a0290587d968f5c1c71b0d5018e078f43ea732a4cdbf837ed42b
 F src/whereexpr.c 19394cb463003e9cc9305730b1508b8817a22bb7247170d81234b691a7f05b89
@@ -1934,7 +1934,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 24ba535d200fc8a99dd8e66c6d100b5f6ae442098bafb152008429398eefe3e7
-R 7eae2a1d2a9d2b173d70c0467bdac4ba
+P 00070e1fff6aec3d7c7b121f2b02bbca38a1664aca9afc3fb7e293f07fd1704f
+R 6ef1a6c68af918fb5dc855e869b3769c
 U drh
-Z 477e7fdac36f7f761dc02a6457a5f233
+Z 7a26146d090468562610338a13462117
diff --git a/manifest.uuid b/manifest.uuid
index a54777d56d..f1d3a5f29a 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-00070e1fff6aec3d7c7b121f2b02bbca38a1664aca9afc3fb7e293f07fd1704f
\ No newline at end of file
+2739ed5192058fbcc816ecbc252be687efc606e038bfcd6cf71194a3f4f5684e
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index e7246b1040..1eb9f36017 100644
--- a/src/where.c
+++ b/src/where.c
@@ -988,7 +988,8 @@ end_auto_index_create:
 static SQLITE_NOINLINE void constructBloomFilter(
   WhereInfo *pWInfo,    /* The WHERE clause */
   int iLevel,           /* Index in pWInfo->a[] that is pLevel */
-  WhereLevel *pLevel    /* Make a Bloom filter for this FROM term */
+  WhereLevel *pLevel,   /* Make a Bloom filter for this FROM term */
+  Bitmask notReady      /* Loops that are not ready */
 ){
   int addrOnce;                        /* Address of opening OP_Once */
   int addrTop;                         /* Address of OP_Rewind */
@@ -1076,7 +1077,9 @@ static SQLITE_NOINLINE void constructBloomFilter(
       iLevel++;
       pLevel = &pWInfo->a[iLevel];
       pLoop = pLevel->pWLoop;
-      if( pLoop && pLoop->wsFlags & WHERE_BLOOMFILTER ) break;
+      if( pLoop==0 ) continue;
+      if( pLoop->prereq & notReady ) continue;
+      if( pLoop->wsFlags & WHERE_BLOOMFILTER ) break;
     }
   }while( iLevel < pWInfo->nLevel );
   sqlite3VdbeJumpHere(v, addrOnce);
@@ -5594,7 +5597,7 @@ WhereInfo *sqlite3WhereBegin(
                   &pTabList->a[pLevel->iFrom], notReady, pLevel);
 #endif
       }else{
-        constructBloomFilter(pWInfo, ii, pLevel);
+        constructBloomFilter(pWInfo, ii, pLevel, notReady);
       }
       if( db->mallocFailed ) goto whereBeginError;
     }