From 47b1d68f25f2c921497c6a642a111d2d8e7d00cc Mon Sep 17 00:00:00 2001 From: drh Date: Sun, 15 Oct 2017 22:16:25 +0000 Subject: [PATCH] In the query planner, do not consider index X to be a proper subset of index Y if X is a covering index but Y is not. FossilOrigin-Name: ee31c04353cd75ea4bbadee2994c30d3808b696a4f680187502d104902988a5d --- manifest | 16 ++++++++-------- manifest.uuid | 2 +- src/where.c | 17 ++++++++++------- test/analyze9.test | 5 ++++- 4 files changed, 23 insertions(+), 17 deletions(-) diff --git a/manifest b/manifest index 1ce91e738e..b77b1484ce 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Updates\sto\sthe\sMakefiles\sfor\sMSVC. -D 2017-10-14T19:54:06.773 +C In\sthe\squery\splanner,\sdo\snot\sconsider\sindex\sX\sto\sbe\sa\sproper\ssubset\sof\s\nindex\sY\sif\sX\sis\sa\scovering\sindex\sbut\sY\sis\snot. +D 2017-10-15T22:16:25.229 F Makefile.in e016061b23e60ac9ec27c65cb577292b6bde0307ca55abd874ab3487b3b1beb2 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434 F Makefile.msc 37740aba9c4bb359c627eadccf1cfd7be4f5f847078723777ea7763969e533b1 @@ -544,7 +544,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9 F src/wal.c 839db09792fead5052bb35e533fa485e134913d547d05b5f42e537b73e63f07a F src/wal.h 8de5d2d3de0956d6f6cb48c83a4012d5f227b8fe940f3a349a4b7e85ebcb492a F src/walker.c 3ccfa8637f95355bff61144e01a615b8ef26f79c312880848da73f03367da1e6 -F src/where.c 049522adcf5426f1a8c3ed07be15e1ffa3266afd34e8e7bee64b63e2fbfad0b5 +F src/where.c 248f0dc6085b37b4b2ccad2de06b90f1a48b1932403ab0ad9100a1f2a6990763 F src/whereInt.h 82c04c5075308abbac59180c8bad5ecb45b07453981f60a53f3c7dee21e1e971 F src/wherecode.c e8c2ece5843ea56e6c90277d421f2d628f3f7b7c976642369cc519f008e1d2b1 F src/whereexpr.c afcac9cccfc0fdaccbdda94034a398947b6dc47dbf821c1b496261722832a6a4 @@ -568,7 +568,7 @@ F test/analyze5.test 765c4e284aa69ca172772aa940946f55629bc8c4 F test/analyze6.test f1c552ce39cca4ec922a7e4e0e5d0203d6b3281f F test/analyze7.test bb1409afc9e8629e414387ef048b8e0e3e0bdc4f F test/analyze8.test c05a461d0a6b05991106467d0c47480f2e709c82 -F test/analyze9.test b817b8e798315fc65b820a5463f73ad5f48ed8dd +F test/analyze9.test dac0bdc7eab965b9ad639ca83564d98717aaf13ce5a776f23d9a3680238cecd8 F test/analyzeA.test 3335697f6700c7052295cfd0067fc5b2aacddf9a F test/analyzeB.test a4c1c3048f6d9e090eb76e83eecb18bcf6d31a70 F test/analyzeC.test 555a6cc388b9818b6eda6df816f01ce0a75d3a93 @@ -1664,7 +1664,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0 -P d65d1f297ddb07b799ff5b2e560575fc59a6fa74c752269cc85ab84348fb7da4 -R 49fa7e54acb9ad8a392e6c25fe8116d5 -U mistachkin -Z 3270bf7f35234fd560a264ffe40cbf35 +P ac8786f3f9f35cb6fa72c65f5ca41cc6659f4702cd29ab0c9dcf04d3d1189090 +R 88b26813bcaf999746e4cf55503b4797 +U drh +Z fe6d8478e3f31cb2dfbec6ce858d4ad8 diff --git a/manifest.uuid b/manifest.uuid index 63b3b0cf2b..12179a84a0 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -ac8786f3f9f35cb6fa72c65f5ca41cc6659f4702cd29ab0c9dcf04d3d1189090 \ No newline at end of file +ee31c04353cd75ea4bbadee2994c30d3808b696a4f680187502d104902988a5d \ No newline at end of file diff --git a/src/where.c b/src/where.c index 5a3d44f9ee..95bbdb157e 100644 --- a/src/where.c +++ b/src/where.c @@ -1885,16 +1885,15 @@ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){ ** Return TRUE if all of the following are true: ** ** (1) X has the same or lower cost that Y -** (2) X is a proper subset of Y -** (3) X skips at least as many columns as Y -** -** By "proper subset" we mean that X uses fewer WHERE clause terms -** than Y and that every WHERE clause term used by X is also used -** by Y. +** (2) X users fewer WHERE clause terms than Y +** (3) Every WHERE clause term used by X is also used by Y +** (4) X skips at least as many columns as Y +** (5) If X is a covering index, than Y is too ** +** Conditions (2) and (3) mean that X is a "proper subset" of Y. ** If X is a proper subset of Y then Y is a better choice and ought ** to have a lower cost. This routine returns TRUE when that cost -** relationship is inverted and needs to be adjusted. The third rule +** relationship is inverted and needs to be adjusted. Constraint (4) ** was added because if X uses skip-scan less than Y it still might ** deserve a lower cost even if it is a proper subset of Y. */ @@ -1918,6 +1917,10 @@ static int whereLoopCheaperProperSubset( } if( j<0 ) return 0; /* X not a subset of Y since term X[i] not used by Y */ } + if( (pX->wsFlags&WHERE_IDX_ONLY)!=0 + && (pY->wsFlags&WHERE_IDX_ONLY)==0 ){ + return 0; /* Constraint (5) */ + } return 1; /* All conditions meet */ } diff --git a/test/analyze9.test b/test/analyze9.test index 918577bd19..7c69806f89 100644 --- a/test/analyze9.test +++ b/test/analyze9.test @@ -1052,8 +1052,11 @@ do_execsql_test 23.0 { do_eqp_test 23.1 { SELECT * FROM t4 WHERE (e=1 AND b='xyz' AND c='zyx' AND a<'AEA') AND f<300 + -- Formerly used index i41. But i41 is not a covering index whereas + -- the PRIMARY KEY is a covering index, and so as of 2017-10-15, the + -- PRIMARY KEY is preferred. } { - 0 0 0 {SEARCH TABLE t4 USING INDEX i41 (e=? AND c=? AND b=? AND a