SQLite version 3.22.0 2018-01-22 18:45:57 Enter ".help" for usage hints. Connected to a transient in-memory database. Use ".open FILENAME" to reopen on a persistent database. sqlite> CREATE TABLE t1 (a INTEGER PRIMARY KEY); sqlite> CREATE TABLE t2 (a INTEGER PRIMARY KEY); sqlite> CREATE TABLE t3 (a INTEGER); sqlite> CREATE UNIQUE INDEX ndx on t3(a); sqlite> EXPLAIN QUERY PLAN SELECT t1.a FROM t1 left join t2 using (a); 0|0|0|SCAN TABLE t1 sqlite> EXPLAIN QUERY PLAN SELECT t1.a FROM t1 left join t3 using (a); 0|0|0|SCAN TABLE t1 0|1|1|SEARCH TABLE t3 USING COVERING INDEX ndx (a=?)
Why is t3 with its unique index on a not omitted from the last query plan? _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
