Fix an issue in the "noquery" decision in the previous check-in. Also add

comments explaining the algorithm.

FossilOrigin-Name: 6aaa65adfc3b0c8e1ee7066de38d4385904c80da704b97440b0699fc78176ffa

diff --git a/manifest b/manifest
index c8a5a8a8203bb93cde8386a1a99bdaaf0a969d7b..2da86ca734d3fa3c69f707c613905583a2c5b2e0 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sthe\s"noquery"\sargument\sas\san\soption\sfor\sthe\sstat\scolumn\sof\nsqlite_stat1.\s\sIf\sset,\sthen\sthe\sindex\swill\snot\sbe\sused\sto\soptimize\sa\squery.\nEnhance\sANALYZE\sto\sset\sthat\sargument\son\svery\slow\sselectivity\sindexes.
-D 2023-12-29T20:08:43.320
+C Fix\san\sissue\sin\sthe\s"noquery"\sdecision\sin\sthe\sprevious\scheck-in.\s\sAlso\sadd\ncomments\sexplaining\sthe\salgorithm.
+D 2023-12-29T20:31:32.065
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -670,7 +670,7 @@ F sqlite3.1 acdff36db796e2d00225b911d3047d580cd136547298435426ce9d40347973cc
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
 F sqlite_cfg.h.in baf2e409c63d4e7a765e17769b6ff17c5a82bbd9cbf1e284fd2e4cefaff3fcf2
 F src/alter.c 30c2333b8bb3af71e4eb9adeadee8aa20edb15917ed44b8422e5cd15f3dfcddc
-F src/analyze.c 803996cd8cb6f030b214b0519b36d0bff8ba21bc85b1127a9d5e7d4f32abee79
+F src/analyze.c 6f88cfaf7e4de1cf9231b0c6c270b0f7d0d11fa0b33868c3890822757ba8df8d
 F src/attach.c cc9d00d30da916ff656038211410ccf04ed784b7564639b9b61d1839ed69fd39
 F src/auth.c 19b7ccacae3dfba23fc6f1d0af68134fa216e9040e53b0681b4715445ea030b4
 F src/backup.c 5c97e8023aab1ce14a42387eb3ae00ba5a0644569e3476f38661fa6f824c3523
@@ -2156,8 +2156,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 4b70b94616ef37bac969051eee3ea6913a28f30520cdd4fc3a19e848f2cf12b7
-R 75c6f66e060d333b8c7cb6dfdfaf830a
+P e514d3fa83662aa19abefebdda5652e6adb0f0b5a75ad7ee9dd3d2d2c87e03c5
+R 5434c613e51a90ac2d4be4dfede8fa3d
 U drh
-Z f8fd342d34818ee6053befc6b4bca435
+Z afc1c4a983fea7e5c946a28458460117
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index 8c9b3a056afad7127cd8aefdd6ffb01515538ed5..ed0edae5599e147112a3abdb4d4e6f49d212fd56 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e514d3fa83662aa19abefebdda5652e6adb0f0b5a75ad7ee9dd3d2d2c87e03c5
\ No newline at end of file
+6aaa65adfc3b0c8e1ee7066de38d4385904c80da704b97440b0699fc78176ffa
\ No newline at end of file

diff --git a/src/analyze.c b/src/analyze.c
index fd5eb763064c9ebe4b111db4a98280f90e0450a5..d4c9806b1d97da9d87180e79d8e980ccc7c66229 100644 (file)
--- a/src/analyze.c
+++ b/src/analyze.c
@@ -891,7 +891,12 @@ static void statGet(
       sqlite3_str_appendf(&sStat, " %llu", iVal);
       assert( p->current.anEq[i] );
     }
-    if( iVal>=1000 && iVal*10>=1000 ){
+    if( iVal>=1000 && iVal*10>=nRow ){
+      /* If this index always matches 1000 or more rows even if all columns
+      ** match, and if the the number of rows matched is 1/10th or more of
+      ** the index, then this is a very low selectivity index.  Mark it as
+      ** "noquery" so that the query planner won't waste any time trying to
+      ** use it. */
       sqlite3_str_appendf(&sStat, " noquery");
     }
     sqlite3ResultStrAccum(context, &sStat);