From: drh <>
Date: Wed, 8 Jun 2022 12:46:58 +0000 (+0000)
Subject: Do not allow a partial index scan on the left table of a RIGHT JOIN, because
X-Git-Tag: version-3.39.0~48
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=093dd41e9790396c31538b4a30b4b62e75d9ac82;p=thirdparty%2Fsqlite.git

Do not allow a partial index scan on the left table of a RIGHT JOIN, because
since the index is partial, some rows will be omitted from the scan, and
those rows will subsequently be picked up by the no-match logic in the
right-join post-processing loop.
[forum:/forumpost/c4676c4956|forum post c4676c4956].

FossilOrigin-Name: 615c0026119f7870c3b6ef9dcb57ce4ecf5acedea3e2b5cfc25aa450eb8f17a0
---

diff --git a/manifest b/manifest
index 4aa68d4fb3..d12aa79280 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Minor\sfix\sto\stest/index9.test\sso\sthat\sit\scan\sbe\sinvoked\swith\sother\nindex\stests\susing\sa\swildcard.
-D 2022-06-08T12:35:39.641
+C Do\snot\sallow\sa\spartial\sindex\sscan\son\sthe\sleft\stable\sof\sa\sRIGHT\sJOIN,\sbecause\nsince\sthe\sindex\sis\spartial,\ssome\srows\swill\sbe\somitted\sfrom\sthe\sscan,\sand\nthose\srows\swill\ssubsequently\sbe\spicked\sup\sby\sthe\sno-match\slogic\sin\sthe\nright-join\spost-processing\sloop.\n[forum:/forumpost/c4676c4956|forum\spost\sc4676c4956].
+D 2022-06-08T12:46:58.728
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -657,7 +657,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c b9df133a705093da8977da5eb202eaadb844839f1c7297c08d33471f5491843d
 F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
 F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c d0fcb3ae11f3bd5bb65ad64fec947c89280ebdd399135818292ad0ccd9d34b8e
+F src/where.c 7da9e0c1275fb3f180beb0d63551ea4d246e028908809bbbcd7f56005872d1bd
 F src/whereInt.h b48ca529ffe293c18cbfa8326af18a09e39910de66fb3e96ef788c7cbf8ef3a7
 F src/wherecode.c 0b09abfcb88c61c6a6984a3e065786631ff35495e9bdf865e6b74ab0a1299c5b
 F src/whereexpr.c 20255cf03e0b765b742301197d165511ff99e95da0d7ee9c8a2ebc1e888dd049
@@ -1129,7 +1129,7 @@ F test/index2.test f835d5e13ca163bd78c4459ca15fd2e4ed487407
 F test/index3.test 51685f39345462b84fcf77eb8537af847fdf438cc96b05c45d6aaca4e473ade0
 F test/index4.test ab92e736d5946840236cd61ac3191f91a7856bf6
 F test/index5.test 8621491915800ec274609e42e02a97d67e9b13e7
-F test/index6.test 6e5b6943f6a97a34898e48c4d0d4990caf55c12c00465a43a9c33d2fd9a3a820
+F test/index6.test b376a648e85aa71c50074382784e6cb0c126ec46e43d1ad15af9a4d234c52e65
 F test/index7.test b238344318e0b4e42126717f6554f0e7dfd0b39cecad4b736039b43e1e3b6eb3
 F test/index8.test caa097735c91dbc23d8a402f5e63a2a03c83840ba3928733ed7f9a03f8a912a3
 F test/index9.test 2ac891806a4136ef3e91280477e23114e67575207dc331e6797fa0ed9379f997
@@ -1975,8 +1975,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 5a107fd7fa01554d73fefc0611e5797b8c23e782ce0df3aeba7e2f288675b2ce
-R 2986076e88142714853261bca3b46a60
+P ccbd6e774903f9202f9311954979f6fcc3b13eba1f3402a549a7aee6ed1d55eb
+R 9e5b91eaa709a211969f755ac60f2577
 U drh
-Z 05db8af407c087478eec7553b71b683c
+Z 3fabe8df6bd5cac6e030c1017487aca1
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index ca7dfd66ba..cb987fab75 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-ccbd6e774903f9202f9311954979f6fcc3b13eba1f3402a549a7aee6ed1d55eb
\ No newline at end of file
+615c0026119f7870c3b6ef9dcb57ce4ecf5acedea3e2b5cfc25aa450eb8f17a0
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index ce32f8bfcb..a89cb36ac4 100644
--- a/src/where.c
+++ b/src/where.c
@@ -3216,7 +3216,10 @@ static int whereUsablePartialIndex(
 ){
   int i;
   WhereTerm *pTerm;
-  Parse *pParse = pWC->pWInfo->pParse;
+  Parse *pParse;
+
+  if( jointype & JT_LTORJ ) return 0;
+  pParse = pWC->pWInfo->pParse;
   while( pWhere->op==TK_AND ){
     if( !whereUsablePartialIndex(iTab,jointype,pWC,pWhere->pLeft) ) return 0;
     pWhere = pWhere->pRight;
diff --git a/test/index6.test b/test/index6.test
index 1ae2ee8753..16370f521d 100644
--- a/test/index6.test
+++ b/test/index6.test
@@ -508,4 +508,24 @@ do_execsql_test index6-18.1 {
   SELECT * FROM t1 WHERE a IS NOT NULL;
 } {10 10}
 
+# 2022-06-09
+# https://sqlite.org/forum/forumpost/c4676c4956
+# Cannot do a scan of a partial index on the left table of a RIGHT JOIN
+# since that will cause extra rows to appear in the output during the
+# right-join no-match loop.  The following testcase is verify using
+# PostgreSQL 14.
+#
+reset_db
+do_execsql_test index6-19.1 {
+  CREATE TABLE t1(a INT, b INT);
+  INSERT INTO t1(a) VALUES(2);
+  CREATE TABLE t2(c INT);
+  CREATE INDEX i0 ON t2(c) WHERE c=3;
+  CREATE TABLE t3(d INT);
+  INSERT INTO t3 VALUES(1);
+}
+do_execsql_test index6-19.2 {
+  SELECT * FROM t2 RIGHT JOIN t3 ON d<>0 LEFT JOIN t1 ON c=3 WHERE t1.a<>0;
+} {}
+
 finish_test