1# 2014-06-17 2# 3# The author disclaims copyright to this source code. In place of 4# a legal notice, here is a blessing: 5# 6# May you do good and not evil. 7# May you find forgiveness for yourself and forgive others. 8# May you share freely, never taking more than you give. 9# 10#************************************************************************* 11# 12# This file implements regression tests for SQLite library. The 13# focus of this script is testing automatic index creation logic, 14# and specifically that an automatic index will not be created that 15# shadows a declared index. 16# 17 18set testdir [file dirname $argv0] 19source $testdir/tester.tcl 20set testprefix autoindex3 21 22# The t1b and t2d indexes are not very selective. It used to be that 23# the autoindex mechanism would create automatic indexes on t1(b) or 24# t2(d), make assumptions that they were reasonably selective, and use 25# them instead of t1b or t2d. But that would be cheating, because the 26# automatic index cannot be any more selective than the real index. 27# 28# This test verifies that the cheat is no longer allowed. 29# 30do_execsql_test autoindex3-100 { 31 CREATE TABLE t1(a,b,x); 32 CREATE TABLE t2(c,d,y); 33 CREATE INDEX t1b ON t1(b); 34 CREATE INDEX t2d ON t2(d); 35 ANALYZE sqlite_master; 36 INSERT INTO sqlite_stat1 VALUES('t1','t1b','10000 500'); 37 INSERT INTO sqlite_stat1 VALUES('t2','t2d','10000 500'); 38 ANALYZE sqlite_master; 39 EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d=b; 40} {~/AUTO/} 41 42# Automatic indexes can still be used if existing indexes do not 43# participate in == constraints. 44# 45do_execsql_test autoindex3-110 { 46 EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d>b AND x=y; 47} {/AUTO/} 48do_execsql_test autoindex3-120 { 49 EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d<b AND x=y; 50} {/AUTO/} 51do_execsql_test autoindex3-130 { 52 EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d IS NULL AND x=y; 53} {/AUTO/} 54do_execsql_test autoindex3-140 { 55 EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d IN (5,b) AND x=y; 56} {/AUTO/} 57 58reset_db 59do_execsql_test 210 { 60 CREATE TABLE v(b, d, e); 61 CREATE TABLE u(a, b, c); 62 ANALYZE sqlite_master; 63 INSERT INTO "sqlite_stat1" VALUES('u','uab','40000 400 1'); 64 INSERT INTO "sqlite_stat1" VALUES('v','vbde','40000 400 1 1'); 65 INSERT INTO "sqlite_stat1" VALUES('v','ve','40000 21'); 66 67 CREATE INDEX uab on u(a, b); 68 CREATE INDEX ve on v(e); 69 CREATE INDEX vbde on v(b,d,e); 70 71 DROP TABLE IF EXISTS sqlite_stat4; 72 ANALYZE sqlite_master; 73} 74 75# At one point, SQLite was using the inferior plan: 76# 77# 0|0|1|SEARCH v USING INDEX ve (e>?) 78# 0|1|0|SEARCH u USING COVERING INDEX uab (ANY(a) AND b=?) 79# 80# on the basis that the real index "uab" must be better than the automatic 81# index. This is not right - a skip-scan is not necessarily better than an 82# automatic index scan. 83# 84do_eqp_test 220 { 85 select count(*) from u, v where u.b = v.b and v.e > 34; 86} { 87 QUERY PLAN 88 |--SEARCH v USING INDEX ve (e>?) 89 `--SEARCH u USING AUTOMATIC COVERING INDEX (b=?) 90} 91 92 93finish_test 94