# 2014-06-17 # # The author disclaims copyright to this source code. In place of # a legal notice, here is a blessing: # # May you do good and not evil. # May you find forgiveness for yourself and forgive others. # May you share freely, never taking more than you give. # #************************************************************************* # # This file implements regression tests for SQLite library. The # focus of this script is testing automatic index creation logic, # and specifically that an automatic index will not be created that # shadows a declared index. # set testdir [file dirname $argv0] source $testdir/tester.tcl set testprefix autoindex3 # The t1b and t2d indexes are not very selective. It used to be that # the autoindex mechanism would create automatic indexes on t1(b) or # t2(d), make assumptions that they were reasonably selective, and use # them instead of t1b or t2d. But that would be cheating, because the # automatic index cannot be any more selective than the real index. # # This test verifies that the cheat is no longer allowed. # do_execsql_test autoindex3-100 { CREATE TABLE t1(a,b,x); CREATE TABLE t2(c,d,y); CREATE INDEX t1b ON t1(b); CREATE INDEX t2d ON t2(d); ANALYZE sqlite_master; INSERT INTO sqlite_stat1 VALUES('t1','t1b','10000 500'); INSERT INTO sqlite_stat1 VALUES('t2','t2d','10000 500'); ANALYZE sqlite_master; EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d=b; } {~/AUTO/} # Automatic indexes can still be used if existing indexes do not # participate in == constraints. # do_execsql_test autoindex3-110 { EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d>b AND x=y; } {/AUTO/} do_execsql_test autoindex3-120 { EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d?) # 0|1|0|SEARCH TABLE u USING COVERING INDEX uab (ANY(a) AND b=?) # # on the basis that the real index "uab" must be better than the automatic # index. This is not right - a skip-scan is not necessarily better than an # automatic index scan. # do_eqp_test 220 { select count(*) from u, v where u.b = v.b and v.e > 34; } { QUERY PLAN |--SEARCH TABLE v USING INDEX ve (e>?) `--SEARCH TABLE u USING AUTOMATIC COVERING INDEX (b=?) } finish_test