From: drh <>
Date: Tue, 28 May 2024 00:01:07 +0000 (+0000)
Subject: Query planner tuning:  Increase the maximum number of simultaneous solutions
X-Git-Tag: version-3.47.0~378
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=38af12523865b98cdc64fa518fc85ea754697e09;p=thirdparty%2Fsqlite.git

Query planner tuning:  Increase the maximum number of simultaneous solutions
to track int eh solver from 10 to 12.

FossilOrigin-Name: fe2e1dadbacbe6392ceed44fd287a2ed82189cb8055f35631d37967d9a7a5d1d
---

diff --git a/manifest b/manifest
index 4e2cea56dd..bd1edcd570 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C The\sprevious\scheck-in\swas\sa\slittle\stwo\saggressive\sabout\sskipping\sthe\ninitialization\sof\sentries\sin\sthe\sCellArray.ixNx\sarray.\s\sFixed\shere.
-D 2024-05-27T19:52:24.258
+C Query\splanner\stuning:\s\sIncrease\sthe\smaximum\snumber\sof\ssimultaneous\ssolutions\nto\strack\sint\seh\ssolver\sfrom\s10\sto\s12.
+D 2024-05-28T00:01:07.835
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -840,7 +840,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 887fc4ca3f020ebb2e376f222069570834ac63bf50111ef0cbf3ae417048ed89
 F src/wal.h ba252daaa94f889f4b2c17c027e823d9be47ce39da1d3799886bbd51f0490452
 F src/walker.c 7c7ea0115345851c3da4e04e2e239a29983b61fb5b038b94eede6aba462640e2
-F src/where.c 9b2ab23fcc2198ebcee1e6e840a9ff22350668bd3a99195a5dc7299d5908370a
+F src/where.c dd7d9eb570c35caf94797814f9d54b187175bd21966f7f4dfd36b0c1f63aa501
 F src/whereInt.h 82a13766f13d1a53b05387c2e60726289ef26404bc7b9b1f7770204d97357fb8
 F src/wherecode.c d5184620bcb5265d59072cb66e1386bfe0331a9ce7614286f9ab79a4fcd00fb8
 F src/whereexpr.c 67d15caf88a1a9528283d68ff578e024cf9fe810b517bb0343e5aaf695ad97dd
@@ -2193,8 +2193,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 428aadf0c71473ccb0681b2b7146281c62949ee99556873e49895d44eec7aee5
-R 4ca5c510c21258f08a4799ee1f04b980
+P 1b6d1fbcdecf14bc79dc7b5df50e585d2fcc1484a9987b863c190e8f7ba2c39f
+R 81c36ec13694e48008fb110fd73a5f00
 U drh
-Z e77b6b7828b797641ee06ff1dc47219a
+Z 108dc3aeba08b8d2b68875bf68eaf849
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 1de423f654..49840006bb 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-1b6d1fbcdecf14bc79dc7b5df50e585d2fcc1484a9987b863c190e8f7ba2c39f
\ No newline at end of file
+fe2e1dadbacbe6392ceed44fd287a2ed82189cb8055f35631d37967d9a7a5d1d
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index a266b51d03..9ef48fb333 100644
--- a/src/where.c
+++ b/src/where.c
@@ -5242,10 +5242,16 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
 
   pParse = pWInfo->pParse;
   nLoop = pWInfo->nLevel;
-  /* TUNING: For simple queries, only the best path is tracked.
-  ** For 2-way joins, the 5 best paths are followed.
-  ** For joins of 3 or more tables, track the 10 best paths */
-  mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 10);
+  /* TUNING: mxChoice is the maximum number of possible paths to preserve
+  ** at each step.  Based on the number of loops in the FROM clause:
+  **
+  **     nLoop      mxChoice
+  **     -----      --------
+  **       1            1            // the most common case
+  **       2            5
+  **       3+          12
+  */
+  mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 12);
   assert( nLoop<=pWInfo->pTabList->nSrc );
   WHERETRACE(0x002, ("---- begin solver.  (nRowEst=%d, nQueryLoop=%d)\n",
                      nRowEst, pParse->nQueryLoop));