When the left-hand side of a WHERE clause contraint is a UNIQUE column,

and that term of the WHERE clause is not used for indexing, assume that the
term reduces the number of output rows by half.  This is one proposed fix
for ticket [e8b674241947eb3ba4]

FossilOrigin-Name: 5c243eec7bcccda3f97c20c2f8a44e2811807615cf0ef378bb548f0791c55964

diff --git a/ext/rtree/rtreeC.test b/ext/rtree/rtreeC.test
index 19a1f7fe6c2a1ee7563122b9b06c7dcf290a78a7..ce5fd87fc06c89c765c478a285bc43c9015282e8 100644 (file)
--- a/ext/rtree/rtreeC.test
+++ b/ext/rtree/rtreeC.test
@@ -177,7 +177,8 @@ do_execsql_test 4.3 {
 #
 reset_db
 do_execsql_test 5.1 {
-  CREATE TABLE t1(x PRIMARY KEY, y);
+  CREATE TABLE t1(x, y);
+  CREATE INDEX t1x ON t1(x);
   CREATE VIRTUAL TABLE rt USING rtree(id, x1, x2, +d1);
 
   INSERT INTO t1(x) VALUES(1);
@@ -221,7 +222,7 @@ do_eqp_test 5.4 {
 } {
   QUERY PLAN
   |--SCAN TABLE rt VIRTUAL TABLE INDEX 2:
-  `--SEARCH TABLE t1 USING INDEX sqlite_autoindex_t1_1 (x=?)
+  `--SEARCH TABLE t1 USING INDEX t1x (x=?)
 }
 
 # Delete the ANALYZE data. "t1" should be the outer loop again.

diff --git a/manifest b/manifest
index 84b2f73d674e79b9bcbf94969f0a633d3ffad7b1..4117adc8bc62954674002e12a995ba6b241e105a 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Changes\sto\sgeopoly\sto\ssilience\sfalse-positive\swarnings\scoming\sout\sof\sclang.
-D 2018-10-05T15:10:00.337
+C When\sthe\sleft-hand\sside\sof\sa\sWHERE\sclause\scontraint\sis\sa\sUNIQUE\scolumn,\nand\sthat\sterm\sof\sthe\sWHERE\sclause\sis\snot\sused\sfor\sindexing,\sassume\sthat\sthe\nterm\sreduces\sthe\snumber\sof\soutput\srows\sby\shalf.\s\sThis\sis\sone\sproposed\sfix\nfor\sticket\s[e8b674241947eb3ba4]
+D 2018-10-05T20:09:07.161
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 01e95208a78b57d056131382c493c963518f36da4c42b12a97eb324401b3a334
@@ -375,7 +375,7 @@ F ext/rtree/rtree8.test 924926d7c64ac59fcca0809de472d9dd73c612f54daae1cf992bdd7d
 F ext/rtree/rtree9.test c646f12c8c1c68ef015c6c043d86a0c42488e2e68ed1bb1b0771a7ca246cbabf
 F ext/rtree/rtreeA.test 20623ca337ca3bd7e008cc9fb49e44dbe97f1a80b238e10a12bb4afcd0da3776
 F ext/rtree/rtreeB.test 4cec297f8e5c588654bbf3c6ed0903f10612be8a2878055dd25faf8c71758bc9
-F ext/rtree/rtreeC.test 128928549d22b65c381ab1366760d08703cd75e34f6a7a506ece38f9330b7282
+F ext/rtree/rtreeC.test c5339c91d51b3342556cf39c999e778658a0de6245fea23edf71269fb3277fd9
 F ext/rtree/rtreeD.test fe46aa7f012e137bd58294409b16c0d43976c3bb92c8f710481e577c4a1100dc
 F ext/rtree/rtreeE.test e65d3fc625da1800b412fc8785817327d43ccfec5f5973912d8c9e471928caa9
 F ext/rtree/rtreeF.test 81ffa7ef51c4e4618d497a57328c265bf576990c7070633b623b23cd450ed331
@@ -588,7 +588,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 3f4f653daf234fe713edbcbca3fec2350417d159d28801feabc702a22c4e213f
 F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
 F src/walker.c fb94aadc9099ff9c6506d0a8b88d51266005bcaa265403f3d7caf732a562eb66
-F src/where.c a54a3d639bcd751d1474deff58e239b2e475a96e1b8f9178aa7864df8782a4e3
+F src/where.c e34d423bec2e2a0c911ee2ecc89ba7cb4dc98869ee6bae1e0e1bd4aace9022e7
 F src/whereInt.h f125f29fca80890768e0b2caa14f95db74b2dacd3a122a168f97aa7b64d6968f
 F src/wherecode.c 3df0a541373d5f999684d761e4bd700d57adb46c7d39da4e77b767b5adcd5893
 F src/whereexpr.c 1b5a5a7876997f65232bbf19c5c1eeb47eb328b8fa5b28c865543052904cde00
@@ -1628,13 +1628,13 @@ F test/whereB.test 0def95db3bdec220a731c7e4bec5930327c1d8c5
 F test/whereC.test cae295158703cb3fc23bf1a108a9ab730efff0f6
 F test/whereD.test 711d4df58d6d4fb9b3f5ce040b818564198be002
 F test/whereE.test b3a055eef928c992b0a33198a7b8dc10eea5ad2f
-F test/whereF.test 3d9412b1199d3e2bed34fcb76b4c48d0bf4df95d27e3f8dd27b6f8b4716d0d89
-F test/whereG.test 0158783235a6dd82fc0e37652b8522b186b9510594ac0a4bff0c4101b4396a52
+F test/whereF.test a7fd9edad2913d1903fcb12b3036cc696ef4302ac5f5e94ec3079674e30c8b2c
+F test/whereG.test 0b2ef829f7c2cbb781577f425c633751ad8376801b91d54d23ec8b3acd239644
 F test/whereH.test e4b07f7a3c2f5d31195cd33710054c78667573b2
 F test/whereI.test b7769ee8dbefd987fb266715fee887f05f9ff180016b06fca7fa402df739193b
 F test/whereJ.test 88287550f6ee604422403b053455b1ad894eeaa5c35d348532dfa1439286cb9a
 F test/whereK.test f8e3cf26a8513ecc7f514f54df9f0572c046c42b
-F test/whereL.test 84de61afe4b8e5a3ff7d741c990d85cb44b3ce798cd8412d5603930f3f75014f
+F test/whereL.test df02ffde4ee09439ad14090976d7e263cb7dc917cc8b6d89a58465ebd96806f6
 F test/wherefault.test 1374c3aa198388925246475f84ad4cd5f9528864
 F test/wherelfault.test 9012e4ef5259058b771606616bd007af5d154e64cc25fa9fd4170f6411db44e3
 F test/wherelimit.test 592081800806d297dd7449b1030c863d2883d6d42901837ccd2e5a9bd962edb0
@@ -1656,7 +1656,7 @@ F test/window6.test 5eae4ae7a590ccf1e605880969ca0bad3955616ac91cad3031baea38748b
 F test/windowfault.test 23abad97b72c6f609002255ddd41ef5c8922408f918f9b98ad6005ab316e482f
 F test/with1.test 2465d98ffce80d00553ac7135697c18b0369275b6ecc750daa2af320b8c812ca
 F test/with2.test e0030e2f0267a910d6c0e4f46f2dfe941c1cc0d4f659ba69b3597728e7e8f1ab
-F test/with3.test 5e8ce2c585170bbbc0544e2a01a4941fa0be173ba5265e5c92eb588cd99a232d
+F test/with3.test 7bc36fd9783ef46030933c38abf37c93fa1703226e3b23c8615629bb000c1372
 F test/with4.test 257be66c0c67fee1defbbac0f685c3465e2cad037f21ce65f23f86084f198205
 F test/withM.test 693b61765f2b387b5e3e24a4536e2e82de15ff64
 F test/without_rowid1.test 533add9100255e4cc430d371b3ecfb79f11f956b86c3a1b9d34413bf8e482d8f
@@ -1770,7 +1770,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P ebcd4523171f0988ff08e2bf36fb8a0caa40efe7ac7556b4eb206784969b03e4
-R 0343e4736757244e342124d3ae0b6945
+P 11d9015f31d1ea2fd27174d4ceea08a145fdbb92a175bec0aae4b90f991694bc
+R 2190696b5de56900d1f70e701b38ef99
+T *branch * unique-constraint-weights
+T *sym-unique-constraint-weights *
+T -sym-trunk *
 U drh
-Z 37c34aea8b9ce101934311a6217c0cb6
+Z 7dfc4105f96c96baaf210fbcaabafa29

diff --git a/manifest.uuid b/manifest.uuid
index 988c0f769ac8f95dc3a7feec9f8af75cadf4377f..7dcc72144b8b4133edf60b188e9850d3f525d83a 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-11d9015f31d1ea2fd27174d4ceea08a145fdbb92a175bec0aae4b90f991694bc
\ No newline at end of file
+5c243eec7bcccda3f97c20c2f8a44e2811807615cf0ef378bb548f0791c55964
\ No newline at end of file

diff --git a/src/where.c b/src/where.c
index bfc11eec18eda4ec73fc91a69878422741eb2c74..571dac87df6894af1466fe4177c172842be8b55e 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -2476,6 +2476,19 @@ static int whereLoopAddBtreeIndex(
 
     if( IsUniqueIndex(pProbe) && saved_nEq==pProbe->nKeyCol-1 ){
       pBuilder->bldFlags |= SQLITE_BLDF_UNIQUE;
+      if( pProbe->nKeyCol==1
+       && pTerm->truthProb>=0
+       && (pTerm->eOperator & (WO_EQ|WO_IS|WO_IN))!=0
+      ){
+        /* If the LHS of an == or IS or IN operator is unique, then
+        ** make the guess that the truth probability of the expression is 50%.
+        ** This is probably an overestimate, but we want to be safe.  Without
+        ** this guess, the truth probability would be 93.75%, which is usually
+        ** a little too high for such a constraint, resulting in an output row
+        ** count that is too large, and throwing off the calcualations on the
+        ** cost of an external sort. */
+        pTerm->truthProb = -10;
+      }
     }else{
       pBuilder->bldFlags |= SQLITE_BLDF_INDEXED;
     }

diff --git a/test/whereF.test b/test/whereF.test
index 121cc3cf22f7a1a7ca9669028f62c2714cd5d9de..df01f2d6bc743d41bf1bf2f0c2a3a62e5bc51a4a 100644 (file)
--- a/test/whereF.test
+++ b/test/whereF.test
@@ -52,8 +52,8 @@ do_execsql_test 1.0 {
   PRAGMA automatic_index = 0;
   CREATE TABLE t1(a, b, c);
   CREATE TABLE t2(d, e, f);
-  CREATE UNIQUE INDEX i1 ON t1(a);
-  CREATE UNIQUE INDEX i2 ON t2(d);
+  CREATE INDEX i1 ON t1(a);
+  CREATE INDEX i2 ON t2(d);
 } {}
 
 foreach {tn sql} {
@@ -72,9 +72,9 @@ do_execsql_test 2.0 {
   CREATE TABLE t1(a, b, c);
   CREATE TABLE t2(d, e, f);
 
-  CREATE UNIQUE INDEX i1 ON t1(a);
-  CREATE UNIQUE INDEX i2 ON t1(b);
-  CREATE UNIQUE INDEX i3 ON t2(d);
+  CREATE INDEX i1 ON t1(a);
+  CREATE INDEX i2 ON t1(b);
+  CREATE INDEX i3 ON t2(d);
 } {}
 
 foreach {tn sql} {

diff --git a/test/whereG.test b/test/whereG.test
index d2e6a4ee96571b01647061941b161df540c663c2..6c889285ba93cbb908fbfe098872b6ef82ea1a53 100644 (file)
--- a/test/whereG.test
+++ b/test/whereG.test
@@ -151,8 +151,8 @@ do_test whereG-2.3 {
 # Commuting a term of the WHERE clause should not change the query plan
 #
 do_execsql_test whereG-3.0 {
-  CREATE TABLE a(a1 PRIMARY KEY, a2);
-  CREATE TABLE b(b1 PRIMARY KEY, b2);
+  CREATE TABLE a(a1, a2);  CREATE INDEX a_1 ON a(a1);
+  CREATE TABLE b(b1, b2);  CREATE INDEX b_1 ON b(b1);
 } {}
 do_eqp_test whereG-3.1 {
   SELECT * FROM a, b WHERE b1=a1 AND a2=5;

diff --git a/test/whereL.test b/test/whereL.test
index 3fe725b8774755c7e0b9a53e2cfd50f925863741..d4ab3caea74829c7c15449011319683d4ef78802 100644 (file)
--- a/test/whereL.test
+++ b/test/whereL.test
@@ -47,8 +47,8 @@ do_eqp_test 120 {
 } {
   QUERY PLAN
   |--SEARCH TABLE t1 USING INDEX sqlite_autoindex_t1_1 (a=?)
-  |--SEARCH TABLE t2 USING INDEX sqlite_autoindex_t2_1 (a=?)
-  `--SCAN TABLE t3
+  |--SEARCH TABLE t2 USING AUTOMATIC PARTIAL COVERING INDEX (a=?)
+  `--SEARCH TABLE t3 USING AUTOMATIC PARTIAL COVERING INDEX (j=?)
 }
 
 # Constant propagation in the face of collating sequences:

diff --git a/test/with3.test b/test/with3.test
index de150b1fc1dd2affca26408af832bb5219f3312d..4e27246d5435ee6f2d21fda80a05a8ca42aeb3b6 100644 (file)
--- a/test/with3.test
+++ b/test/with3.test
@@ -126,8 +126,8 @@ do_eqp_test 3.2.2 {
   |     |--SCAN TABLE w1
   |     `--SCAN TABLE c
   |--SCAN SUBQUERY xxxxxx
-  |--SEARCH TABLE w2 USING INTEGER PRIMARY KEY (rowid=?)
-  `--SEARCH TABLE w1 USING INTEGER PRIMARY KEY (rowid=?)
+  |--SEARCH TABLE w1 USING INTEGER PRIMARY KEY (rowid=?)
+  `--SEARCH TABLE w2 USING INTEGER PRIMARY KEY (rowid=?)
 }
 
 finish_test