Fix a fairly obscure problem causing the planner to sometimes choose sub-optimal...

FossilOrigin-Name: f5752517f590b37bfc0267650f5800320e22a8ecaba34aa6893281ce8d268026

diff --git a/manifest b/manifest
index 1da91a9e83a75a183273f46188cb03784d0e32fd..67a36958378ea20b3325fb3f7d4be131e86de1ae 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\stypos\sin\sthe\scomments\sof\sthe\ssessions\sextension,\sone\sof\swhich\saffects\nthe\sgenerated\sdocumentation.\sNo\scode\schanges.
-D 2019-03-29T11:48:10.580
+C Fix\sa\sfairly\sobscure\sproblem\scausing\sthe\splanner\sto\ssometimes\schoose\ssub-optimal\splans\sfor\sa\squery\swith\sa\ssingle\svirtual\stable\sin\sthe\sFROM\sclause,\sand\sat\sleast\sone\sIN(...)\sconstraint\sin\sthe\sWHERE\sclause.
+D 2019-03-29T13:17:50.351
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -601,7 +601,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 3f4f653daf234fe713edbcbca3fec2350417d159d28801feabc702a22c4e213f
 F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
 F src/walker.c 7607f1a68130c028255d8d56094ea602fc402c79e1e35a46e6282849d90d5fe4
-F src/where.c 8a207cb2ca6b99e1edb1e4bbff9b0504385a759cbf66180d1deb34d80ca4b799
+F src/where.c ff2955dc2743c1af05ba5a8232ab72724d9a63b76dbee256368f40fd3ef82db5
 F src/whereInt.h 5f14db426ca46a83eabab1ae9aa6d4b8f27504ad35b64c290916289b1ddb2e88
 F src/wherecode.c 6fa4056c5ce019e4a8af33795906340176813cb3c1236f4b7b08df76a1b6287b
 F src/whereexpr.c 90859652920f153d2c03f075488744be2926625ebd36911bcbcb17d0d29c891c
@@ -679,7 +679,7 @@ F test/backup_malloc.test 0c9abdf74c51e7bedb66d504cd684f28d4bd4027
 F test/badutf.test d5360fc31f643d37a973ab0d8b4fb85799c3169f
 F test/badutf2.test f5bc7f2d280670ecd79b9cf4f0f1760c607fe51f
 F test/bc_common.tcl b5e42d80305be95697e6370e015af571e5333a1c
-F test/bestindex1.test 852170bddbb21daa121fabcc274640ff83d7d8705912e8b5fe7ed2c5a9a9224a
+F test/bestindex1.test 705b57d7f51d53ee5fd043dd9666236e1fc18f4d59abf51da0ea5ea1b4804947
 F test/bestindex2.test 9a0ccd320b6525eec3a706aae6cdab7e1b7b5abca75027e39f39f755e76e5928
 F test/bestindex3.test 7622e792ff2da16d262d3cea6ad914591ac4806d57ed128e6c940b7920b47b84
 F test/bestindex4.test 038e3d0789332f3f1d61474f9bbc9c6d08c6bd1783a978f31f38ad82688de601
@@ -1813,7 +1813,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 965cbcea117835d2c6d2ec58c8025b227f491c35805e282cb31228436bc6bec1
-R ef1c408597d0be46fbc1470ecf47aa02
-U drh
-Z 8c0f94643e07344b7f966cc60e0031a9
+P 040d5d515bcb37bea05e0d156dbaf066c68052ac574f1b0b2cb118d473a353e0
+R e546ad670b8973ed4f54c42d6a6b4e3e
+U dan
+Z 48108f154421a71bdf9883e42b6bbc73

diff --git a/manifest.uuid b/manifest.uuid
index 93ea535d7a7c33a3e2f5277757199706fc08d47a..2802f66d1d465650b1960ea31421f756b9007d21 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-040d5d515bcb37bea05e0d156dbaf066c68052ac574f1b0b2cb118d473a353e0
\ No newline at end of file
+f5752517f590b37bfc0267650f5800320e22a8ecaba34aa6893281ce8d268026
\ No newline at end of file

diff --git a/src/where.c b/src/where.c
index a09f7624f84948252697fea173e99c62bd5aaeb0..cd00fe96b89532d3955b5c2b99adf20f1d6d9679 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -3335,11 +3335,11 @@ static int whereLoopAddVirtual(
   rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, 0, p, mNoOmit, &bIn);
 
   /* If the call to xBestIndex() with all terms enabled produced a plan
-  ** that does not require any source tables (IOW: a plan with mBest==0),
-  ** then there is no point in making any further calls to xBestIndex() 
-  ** since they will all return the same result (if the xBestIndex()
-  ** implementation is sane). */
-  if( rc==SQLITE_OK && (mBest = (pNew->prereq & ~mPrereq))!=0 ){
+  ** that does not require any source tables (IOW: a plan with mBest==0)
+  ** and does not use an IN(...) operator, then there is no point in making 
+  ** any further calls to xBestIndex() since they will all return the same
+  ** result (if the xBestIndex() implementation is sane). */
+  if( rc==SQLITE_OK && ((mBest = (pNew->prereq & ~mPrereq))!=0 || bIn) ){
     int seenZero = 0;             /* True if a plan with no prereqs seen */
     int seenZeroNoIN = 0;         /* Plan with no prereqs and no IN(...) seen */
     Bitmask mPrev = 0;

diff --git a/test/bestindex1.test b/test/bestindex1.test
index 1d79c73166854bdab41f91dd4f48b842e2807ad4..b97af111408aca37d31cf8aaee023ed2ecea9ba5 100644 (file)
--- a/test/bestindex1.test
+++ b/test/bestindex1.test
@@ -266,5 +266,62 @@ do_execsql_test 3.5 {
   4 0 ValueB 4 0 ValueB
 }
 
+#-------------------------------------------------------------------------
+# If there is an IN(..) condition in the WHERE clause of a query on a
+# virtual table, the xBestIndex method is first invoked with the IN(...)
+# represented by a "usable" SQLITE_INDEX_CONSTRAINT_EQ constraint. If
+# the virtual table elects to use the IN(...) constraint, then the 
+# xBestIndex method is invoked again, this time with the IN(...) marked
+# as "not usable". Depending on the relative costs of the two plans as
+# defined by the virtual table implementation, and the cardinality of the
+# IN(...) operator, SQLite chooses the most efficient plan. 
+#
+# At one point the second invocation of xBestIndex() was only being made
+# for join queries. The following tests check that this problem has been
+# fixed.
+#
+proc vtab_command {method args} {
+  switch -- $method {
+    xConnect {
+      return "CREATE TABLE t1(a, b, c, d)"
+    }
+
+    xBestIndex {
+      set clist [lindex $args 0]
+      lappend ::bestindex_calls $clist
+      set ret "cost 1000000 idxnum 555"
+      for {set i 0} {$i < [llength $clist]} {incr i} {
+        array set C [lindex $clist $i]
+        if {$C(usable)} { lappend ret use $i }
+      }
+      return $ret
+    }
+  }
+  return {}
+}
+
+do_execsql_test 4.0 {
+  CREATE VIRTUAL TABLE x1 USING tcl(vtab_command);
+} {}
+
+do_test 4.1 {
+  set ::bestindex_calls [list]
+  execsql {
+    SELECT * FROM x1 WHERE a=? AND b BETWEEN ? AND ? AND c IN (1, 2, 3, 4);
+  }
+  set ::bestindex_calls
+} [list \
+    [list {op eq column 0 usable 1} \
+          {op eq column 2 usable 1} \
+          {op ge column 1 usable 1} \
+          {op le column 1 usable 1} \
+    ] \
+    [list {op eq column 0 usable 1} \
+          {op eq column 2 usable 0} \
+          {op ge column 1 usable 1} \
+          {op le column 1 usable 1}
+    ]
+]
+
 
 finish_test