# # MariaDB tests for EXPLAIN UPDATE/DELETE. # --source include/have_partition.inc --disable_warnings drop table if exists t0, t1; --enable_warnings create table t0 (a int) engine=myisam; insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8); --echo # --echo # Tests for single-table DELETE --echo # explain select * from t0 where a=3; explain delete from t0 where a=3; --echo # DELETE without WHERE is a special case: explain delete from t0; create table t1 (a int, b int, filler char(100), key(a), key(b)); insert into t1 select A.a+10*B.a + 10*C.a, A.a+10*B.a + 10*C.a, 'filler' from t0 A, t0 B, t0 C; --echo # This should use an index, possible_keys=NULL because there is no WHERE explain delete from t1 order by a limit 2; --echo # This should use range, possible_keys={a,b} explain delete from t1 where a<20 and b < 10; --echo # This should use ALL + filesort explain delete from t1 order by a+1 limit 2; --echo # This should use range + using filesort explain delete from t1 where a<20 order by b limit 2; --echo # Try some subqueries: explain delete from t1 where a < (select max(a) from t0); explain delete from t1 where a < (select max(a) from t0 where a < t1.b); --echo # --echo # Tests for multi-table DELETE --echo # explain delete t1 from t0, t1 where t0.a = t1.a; drop table t0, t1; --echo # ################################################################### --echo # ## EXPLAIN UPDATE tests --echo # ################################################################### create table t0 (a int) engine=myisam; insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8); explain update t0 set a=3 where a=4; create table t1 (a int, b int, filler char(100), key(a), key(b)); insert into t1 select A.a+10*B.a + 10*C.a, A.a+10*B.a + 10*C.a, 'filler' from t0 A, t0 B, t0 C; explain update t1 set a=a+1 where 3>4; explain update t1 set a=a+1 where a=3 and a=4; --echo # This should use an index, possible_keys=NULL because there is no WHERE explain update t1 set a=a+1 order by a limit 2; --echo # This should use range, possible_keys={a,b} explain update t1 set filler='fooo' where a<20 and b < 10; --echo # This should use ALL + filesort explain update t1 set filler='fooo' order by a+1 limit 2; --echo # This should use range + using filesort explain update t1 set filler='fooo' where a<20 order by b limit 2; --echo # Try some subqueries: explain update t1 set filler='fooo' where a < (select max(a) from t0); explain update t1 set filler='fooo' where a < (select max(a) from t0 where a < t1.b); --echo # --echo # Tests for multi-table UPDATE --echo # explain update t0, t1 set t1.a=t1.a+1 where t0.a = t1.a; drop table t0, t1; --echo # --echo # Try DELETE ... RETURNING ... --echo # create table t0 (a int); insert into t0 values (1),(2),(3),(4); explain delete from t0 where a=1 returning a; explain delete from t0 returning a; drop table t0; --echo # --echo # MDEV-5070 - EXPLAIN INSERT ... SELECT crashes on 10.0-base-explain-slowquerylog --echo # create table t0 (a int); insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8); create table t1 (a int); explain insert into t1 select * from t0; explain replace into t1 select * from t0; drop table t0, t1; --echo # --echo # MDEV-5067: Valgrind warnings (Invalid read) in QPF_table_access::print_explain --echo # CREATE TABLE t1 (i INT) ENGINE=MyISAM; INSERT INTO t1 VALUES (7),(0),(9); SELECT * FROM t1 INNER JOIN ( SELECT DISTINCT * FROM t1 ) AS sq ON (sq.i = t1.i); DROP TABLE t1; --echo # --echo # MDEV-5093, MDEV-5094: EXPLAIN PARTITIONS and EXPLAIN EXTENDED do not --echo # work for EXPLAIN UPDATE. --echo # create table t1 (i int); explain partitions update t1 set i = 3; create table t2 (a int, b int) partition by hash(a) partitions 5; insert into t2 values (0,0),(1,1),(2,2),(3,3),(4,4); explain partitions update t2 set b=3 where a in (3,4); explain partitions delete from t2 where a in (3,4); explain extended update t2 set b=3 where a in (3,4); explain extended delete from t2 where a in (3,4); drop table t1,t2; --echo # --echo # Check the special case where partition pruning removed all partitions --echo # create table t1 (a int, b int) partition by range (a) ( partition p0 values less than (10), partition p1 values less than (20), partition p2 values less than (30) ); insert into t1 values (9,9), (19,19), (29,29); explain partitions select * from t1 where a in (32,33); explain partitions delete from t1 where a in (32,33); explain partitions update t1 set b=12345 where a in (32,33); drop table t1;