# # Tests for SHOW EXPLAIN FOR functionality # # Tests will be skipped for the view protocol because the view protocol creates # an additional util connection and other statistics data -- source include/no_view_protocol.inc --source include/have_debug.inc --source include/have_debug_sync.inc --source include/have_innodb.inc --source include/have_perfschema.inc # Using valgrind can cause 'reap' to fail. See comment below --source include/not_valgrind.inc --disable_warnings drop table if exists t0, t1, t2, t3, t4; drop view if exists v1; --enable_warnings SET @old_debug= @@session.debug_dbug; # # Testcases in this file do not work with embedded server. The reason for this # is that we use the following commands for synchronization: # # set @show_explain_probe_select_id=1; # SET debug_dbug='d,show_explain_probe_join_exec_start'; # send select count(*) from t1 where a < 100000; # # When ran with mysqltest_embedded, this translates into: # # Thread1> DBUG_PUSH("d,show_explain_probe_join_exec_start"); # Thread1> create another thread for doing "send ... reap" # Thread2> mysql_parse("select count(*) from t1 where a < 100000"); # # That is, "select count(*) ..." is ran in a thread for which DBUG_PUSH(...) # has not been called. As a result, show_explain_probe_join_exec_start does not fire, and # "select count(*) ..." does not wait till its SHOW EXPLAIN command, and the # test fails. # -- source include/not_embedded.inc set debug_sync='RESET'; create table t0 (a int); insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t1 (a int); insert into t1 select A.a + 10*B.a + 100*C.a from t0 A, t0 B, t0 C; alter table t1 add b int, add c int, add filler char(32); update t1 set b=a, c=a, filler='fooo'; alter table t1 add key(a), add key(b); # # Try to call SHOW EXPLAIN with a missing thread ID # --error ER_PARSE_ERROR show explain for; # # Also test MySQL-compatible syntax EXPLAIN FOR CONNECTION which was introduced for MDEV-10000 # --error ER_PARSE_ERROR explain for connection; # # Try to call SHOW EXPLAIN/EXPLAIN FOR CONNECTION for a non-existent thread # --error ER_NO_SUCH_THREAD show explain for 2000000000; --error ER_NO_SUCH_THREAD explain for connection 2000000000; --error ER_SET_CONSTANTS_ONLY show explain for (select max(a) from t0); --error ER_SET_CONSTANTS_ONLY explain for connection (select max(a) from t0); # # Setup two threads and their ids # let $thr1=`select connection_id()`; connect (con1, localhost, root,,); connection con1; let $thr2=`select connection_id()`; SET @old_debug= @@session.debug_dbug; connection default; # SHOW EXPLAIN FOR --error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; --error ER_TARGET_NOT_EXPLAINABLE evalp explain for connection $thr2; # SHOW EXPLAIN FOR --error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr1; --error ER_TARGET_NOT_EXPLAINABLE evalp explain for connection $thr1; let $wait_condition= select State='show_explain_trap' from information_schema.processlist where id=$thr2; # # Test SHOW EXPLAIN/EXPLAIN FOR CONNECTION for simple queries # connection con1; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select count(*) from t1 where a < 100000; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; send select max(c) from t1 where a < 10; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; send select max(c) from t1 where a < 10; connection default; --source include/wait_condition.inc evalp explain for connection $thr2; connection con1; reap; --echo # We can catch EXPLAIN, too. set @show_expl_tmp= @@optimizer_switch; set optimizer_switch='index_condition_pushdown=on,mrr=on,mrr_sort_keys=on'; send explain select max(c) from t1 where a < 10; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; --echo # Same for EXPLAIN FOR CONNECTION send explain select max(c) from t1 where a < 10; connection default; --source include/wait_condition.inc evalp explain for connection $thr2; connection con1; reap; set optimizer_switch= @show_expl_tmp; SET debug_dbug=@old_debug; --echo # UNION, first branch set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send explain select a from t0 A union select a+1 from t0 B; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # UNION, second branch set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send explain select a from t0 A union select a+1 from t0 B; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # Uncorrelated subquery, select set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select a, (select max(a) from t0 B) from t0 A where a<1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # Uncorrelated subquery, explain set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send explain select a, (select max(a) from t0 B) from t0 A where a<1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # correlated subquery, select set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # correlated subquery, explain set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send explain select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # correlated subquery, select, while inside the subquery set @show_explain_probe_select_id=2; # <--- SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # correlated subquery, explain, while inside the subquery set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # correlated subquery, explain, while inside the subquery set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_end'; send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; # TODO: explain in the parent subuqery when the un-correlated child has been # run (and have done irreversible cleanups) # ^^ Is this at all possible after 5.3? # Maybe, for 5.3 try this: # - run before/after the parent has invoked child's optimization # - run after materialization --echo # Try to do SHOW EXPLAIN for a query that runs a SET command: --echo # I've found experimentally that select_id==2 here... --echo # set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send set @foo= (select max(a) from t0 where sin(a) >0); connection default; --source include/wait_condition.inc --error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # --echo # Attempt SHOW EXPLAIN for an UPDATE --echo # create table t2 as select a as a, a as dummy from t0 limit 2; set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send update t2 set dummy=0 where (select max(a) from t0 where t2.a + t0.a <3) >3 ; connection default; --source include/wait_condition.inc #--error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; --source include/wait_condition.inc #--error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; connection con1; reap; --echo # --echo # EXPLAIN FOR CONNECTION for an UPDATE --echo # set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send update t2 set dummy=0 where (select max(a) from t0 where t2.a + t0.a <3) >3 ; connection default; --source include/wait_condition.inc evalp explain for connection $thr2; --source include/wait_condition.inc evalp explain for connection $thr2; connection con1; reap; drop table t2; SET debug_dbug=@old_debug; --echo # --echo # Attempt SHOW EXPLAIN for a DELETE (UPD: now works) --echo # create table t2 as select a as a, a as dummy from t0 limit 2; set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send delete from t2 where (select max(a) from t0 where t2.a + t0.a <3) >3 ; connection default; --source include/wait_condition.inc #--error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; --source include/wait_condition.inc #--error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; connection con1; reap; drop table t2; SET debug_dbug=@old_debug; --echo # --echo # Attempt EXPLAIN FOR CONNECTION for a DELETE --echo # create table t2 as select a as a, a as dummy from t0 limit 2; set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send delete from t2 where (select max(a) from t0 where t2.a + t0.a <3) >3 ; connection default; --source include/wait_condition.inc evalp explain for connection $thr2; --source include/wait_condition.inc evalp explain for connection $thr2; connection con1; reap; drop table t2; SET debug_dbug=@old_debug; --echo # --echo # Multiple SHOW EXPLAIN calls for one select --echo # create table t2 as select a as a, a as dummy from t0 limit 3; set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select t2.a, ((select max(a) from t0 where t2.a + t0.a <3) >3) as SUBQ from t2; connection default; --source include/wait_condition.inc evalp show explain for $thr2; --source include/wait_condition.inc evalp show explain for $thr2; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; drop table t2; SET debug_dbug=@old_debug; --echo # --echo # Multiple EXPLAIN FOR CONNECTION calls for one select --echo # create table t2 as select a as a, a as dummy from t0 limit 3; set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select t2.a, ((select max(a) from t0 where t2.a + t0.a <3) >3) as SUBQ from t2; connection default; --source include/wait_condition.inc evalp explain for connection $thr2; --source include/wait_condition.inc evalp explain for connection $thr2; --source include/wait_condition.inc evalp explain for connection $thr2; connection con1; reap; drop table t2; SET debug_dbug=@old_debug; --echo # --echo # SHOW EXPLAIN for SELECT ... ORDER BY with "Using filesort" --echo # explain select * from t0 order by a; SET debug_dbug='+d,show_explain_probe_join_exec_start'; set @show_explain_probe_select_id=1; send select * from t0 order by a; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # --echo # SHOW EXPLAIN for SELECT ... with "Using temporary" --echo # connection default; explain select distinct a from t0; connection con1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; set @show_explain_probe_select_id=1; send select distinct a from t0; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # --echo # SHOW EXPLAIN for SELECT ... with "Using temporary; Using filesort" --echo # connection default; explain select distinct a from t0; connection con1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; set @show_explain_probe_select_id=1; send select distinct a from t0; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # --echo # MDEV-238: SHOW EXPLAIN: Server crashes in JOIN::print_explain with FROM subquery and GROUP BY --echo # CREATE TABLE t2 ( a INT ); INSERT INTO t2 VALUES (1),(2),(1),(4),(2); explain SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a; SET debug_dbug='+d,show_explain_in_find_all_keys'; send SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a; connection default; --source include/wait_condition.inc --echo # FIXED by "conservative assumptions about when QEP is available" fix: --echo # NOTE: current code will not show "Using join buffer": #--error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t2; --echo # --echo # MDEV-239: Assertion `field_types == 0 ... ' failed in Protocol_text::store(double, uint32, String*) with --echo # SHOW EXPLAIN over EXPLAIN EXTENDED --echo # CREATE TABLE t2 (a INT); INSERT INTO t2 VALUES (1),(2),(1),(4),(2); EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a ; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_end'; send EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a ; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t2; --echo # --echo # MDEV-240: SHOW EXPLAIN: Assertion `this->optimized == 2' failed in --echo # JOIN::print_explain on query with a JOIN, TEMPTABLE view, --echo # CREATE TABLE t3 (a INT); CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t3; INSERT INTO t3 VALUES (8); CREATE TABLE t2 (b INT); INSERT INTO t2 VALUES (4),(5),(6),(7),(8),(9); explain SELECT * FROM v1, t2; set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_join_exec_end'; send SELECT * FROM v1, t2; connection default; --source include/wait_condition.inc --error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP VIEW v1; DROP TABLE t2, t3; --echo # --echo # MDEV-267: SHOW EXPLAIN: Server crashes in JOIN::print_explain on most of queries --echo # set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_end'; send select sleep(1); connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # --echo # Same as above, but try another reason for JOIN to be degenerate --echo # set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_end'; send select * from t0 where 1>10; connection default; --source include/wait_condition.inc #--error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # --echo # Same as above, but try another reason for JOIN to be degenerate (2) --echo # create table t3(a int primary key); insert into t3 select a from t0; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_end'; send select * from t0,t3 where t3.a=112233; connection default; --source include/wait_condition.inc # --error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; drop table t3; --echo # --echo # MDEV-270: SHOW EXPLAIN: server crashes in JOIN::print_explain on a query with --echo # select tables optimized away --echo # CREATE TABLE t2 (pk INT PRIMARY KEY, a INT ) ENGINE=MyISAM; INSERT INTO t2 VALUES (1,4),(2,62),(3,7),(4,1),(5,0),(6,7),(7,7),(8,1),(9,7),(10,1), (11,5),(12,2),(13,0),(14,1),(15,8),(16,1),(17,1),(18,9),(19,1),(20,5) ; explain SELECT * FROM t2 WHERE a = (SELECT MAX(a) FROM t2 WHERE pk= (SELECT MAX(pk) FROM t2 WHERE pk = 3) ); set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_do_select'; send SELECT * FROM t2 WHERE a = (SELECT MAX(a) FROM t2 WHERE pk= (SELECT MAX(pk) FROM t2 WHERE pk = 3) ); connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; drop table t2; --echo # --echo # MDEV-273: SHOW EXPLAIN: server crashes in JOIN::print_explain on a query with impossible WHERE --echo # CREATE TABLE t2 (a1 INT, KEY(a1)) ENGINE=MyISAM; INSERT INTO t2 VALUES (4),(6),(7),(1),(0),(7),(7),(1),(7),(1), (5),(2),(0),(1),(8),(1),(1),(9),(1),(5); CREATE TABLE t3 (b1 INT) ENGINE=MyISAM; INSERT INTO t3 VALUES (4),(5),(8),(4),(8),(2),(9),(6),(4),(8), (3),(5),(9),(6),(8),(3),(2),(6),(3),(1), (4),(3),(1),(7),(0),(0),(9),(5),(9),(0), (2),(2),(5),(9),(1),(4),(8),(6),(5),(5), (1),(7),(2),(8),(9),(3),(2),(6),(6),(5), (4),(3),(2),(7),(4),(6),(0),(8),(5),(8), (2),(9),(7),(5),(7),(0),(4),(3),(1),(0), (6),(2),(8),(3),(7),(3),(5),(5),(1),(2), (1),(7),(1),(9),(9),(8),(3); CREATE TABLE t4 (c1 INT) ENGINE=MyISAM; EXPLAIN SELECT count(*) FROM t2, t3 WHERE a1 < ALL ( SELECT a1 FROM t2 WHERE a1 IN ( SELECT a1 FROM t2, t4 ) ); set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_do_select'; send SELECT count(*) FROM t2, t3 WHERE a1 < ALL ( SELECT a1 FROM t2 WHERE a1 IN ( SELECT a1 FROM t2, t4 ) ); connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; drop table t2, t3, t4; --echo # --echo # MDEV-275: SHOW EXPLAIN: server crashes in JOIN::print_explain with IN subquery and aggregate function --echo # CREATE TABLE t2 ( `pk` INT NOT NULL PRIMARY KEY, `a1` INT NOT NULL, KEY(`a1`)) ENGINE=MyISAM; INSERT INTO t2 VALUES (1,5),(2,4),(3,6),(4,9),(5,2),(6,8),(7,4),(8,8),(9,0),(10,43), (11,23),(12,3),(13,45),(14,16),(15,2),(16,33),(17,2),(18,5),(19,9),(20,2); set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_end'; send SELECT * FROM t2 WHERE (5, 78) IN (SELECT `a1`, MAX(`a1`) FROM t2 GROUP BY `a1`); connection default; --source include/wait_condition.inc # --error ER_TARGET_NOT_EXPLAINABLE evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t2; DROP TABLE t1; --echo # --echo # MDEV-305: SHOW EXPLAIN: ref returned by SHOW EXPLAIN is different from the normal EXPLAIN ('const' vs empty string) --echo # CREATE TABLE t1(a INT, KEY(a)); INSERT INTO t1 VALUES (3),(1),(5),(1); set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send SELECT 'test' FROM t1 WHERE a=1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t1; --echo # --echo # MDEV-299: SHOW EXPLAIN: Plan produced by SHOW EXPLAIN changes back and forth during query execution --echo # create table t1 (key1 int, col1 int, col2 int, filler char(100), key(key1)); insert into t1 select A.a+ 10 * B.a, 10, 10, 'filler-data' from t0 A, t0 B; # Make matches 3 records update t1 set col1=3, col2=10 where key1=1; # small range update t1 set col1=3, col2=1000 where key1=2; # big range update t1 set col1=3, col2=10 where key1=3; # small range again update t1 set col1=3, col2=1000 where key1=4; # big range set @tmp_mdev299_jcl= @@join_cache_level; set join_cache_level=0; explain select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_test_if_quick_select'; send select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100; connection default; --source include/wait_condition.inc evalp show explain for $thr2; --source include/wait_condition.inc evalp show explain for $thr2; --source include/wait_condition.inc evalp show explain for $thr2; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; drop table t1; --echo # --echo # MDEV-297: SHOW EXPLAIN: Server gets stuck until timeout occurs while --echo # executing SHOW INDEX and SHOW EXPLAIN in parallel --echo # CREATE TABLE t1(a INT, b INT, c INT, KEY(a), KEY(b), KEY(c)); INSERT INTO t1 (a) VALUES (3),(1),(5),(1); set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send SHOW INDEX FROM t1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t1; --echo # --echo # MDEV-324: SHOW EXPLAIN: Plan produced by SHOW EXPLAIN for a query with TEMPTABLE view --echo # loses 'DERIVED' line on the way without saying that the plan was already deleted --echo # CREATE TABLE t1 (a INT); INSERT INTO t1 VALUES (1),(2); CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t1; EXPLAIN SELECT a + 1 FROM v1; SET debug_dbug='+d,show_explain_probe_join_tab_preread'; set @show_explain_probe_select_id=1; send SELECT a + 1 FROM v1; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP VIEW v1; DROP TABLE t1; --echo # --echo # MDEV-323: SHOW EXPLAIN: Plan produced by SHOW EXPLAIN loses --echo # 'UNION RESULT' line on the way without saying that the plan was already deleted --echo # CREATE TABLE t1 (a INT); INSERT INTO t1 VALUES (4),(6); EXPLAIN SELECT a FROM t1 WHERE a IN ( SELECT 1+SLEEP(0.01) UNION SELECT 2 ); SET debug_dbug='+d,show_explain_probe_union_read'; send SELECT a FROM t1 WHERE a IN ( SELECT 1+SLEEP(0.01) UNION SELECT 2 ); connection default; --source include/wait_condition.inc evalp show explain for $thr2; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t1; --echo # --echo # MDEV-327: SHOW EXPLAIN: Different select_type in plans produced by SHOW EXPLAIN --echo # and standard EXPLAIN: 'SUBQUERY' vs 'DEPENDENT SUBQUERY' --echo # CREATE TABLE t1 (a INT) ENGINE=Aria; INSERT INTO t1 VALUES (4),(6),(3),(5),(3),(246),(2),(9),(3),(8), (1),(8),(8),(5),(7),(5),(1),(6),(2),(9); CREATE TABLE t2 (b INT) ENGINE=Aria; INSERT INTO t2 VALUES (1),(7),(4),(7),(0),(2),(9),(4),(0),(9), (1),(3),(8),(8),(18),(84),(6),(3),(6),(6); EXPLAIN SELECT * FROM t1, ( SELECT * FROM t2 ) AS alias WHERE a < ALL ( SELECT b FROM t1, t2 WHERE a = b ); set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; --send SELECT * FROM t1, ( SELECT * FROM t2 ) AS alias WHERE a < ALL ( SELECT b FROM t1, t2 WHERE a = b ); connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t1, t2; --echo # --echo # Test that SHOW EXPLAIN will print 'Distinct'. --echo # CREATE TABLE t1 (a int(10) unsigned not null primary key,b int(10) unsigned); INSERT INTO t1 VALUES (1,1),(2,1),(3,1),(4,1); CREATE TABLE t3 (a int(10) unsigned, key(A), b text); INSERT INTO t3 VALUES (1,'1'),(2,'2'); create temporary table t4 select * from t3; insert into t3 select * from t4; insert into t4 select * from t3; insert into t3 select * from t4; insert into t4 select * from t3; insert into t3 select * from t4; insert into t4 select * from t3; insert into t3 select * from t4; explain select distinct t1.a from t1,t3 where t1.a=t3.a; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; --send select distinct t1.a from t1,t3 where t1.a=t3.a; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; drop table t1,t3,t4; --echo # --echo # ---------- SHOW EXPLAIN and permissions ----------------- --echo # create user test2@localhost; grant ALL on test.* to test2@localhost; # Give the user SUPER privilege so it can SET debug_dbug variable. grant super on *.* to test2@localhost; connect (con2, localhost, test2,,); connection con1; --echo # --echo # First, make sure that user 'test2' cannot do SHOW EXPLAIN on us --echo # set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select * from t0 where a < 3; connection default; --source include/wait_condition.inc connection con2; --error ER_SPECIFIC_ACCESS_DENIED_ERROR evalp show explain for $thr2; connection default; evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; --echo # --echo # Check that user test2 can do SHOW EXPLAIN on its own queries --echo # connect (con3, localhost, test2,,); connection con2; let $thr_con2=`select connection_id()`; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select * from t0 where a < 3; connection con1; let $save_wait_condition= $wait_condition; let $wait_condition= select State='show_explain_trap' from information_schema.processlist where id=$thr_con2; --source include/wait_condition.inc connection con3; evalp show explain for $thr_con2; connection con2; reap; connection con1; disconnect con3; let $wait_condition= $save_wait_condition; --echo # --echo # Now, grant test2 a PROCESSLIST permission, and see that he's able to observe us --echo # disconnect con2; grant process on *.* to test2@localhost; connect (con2, localhost, test2,,); connection con1; SET debug_dbug=@old_debug; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select * from t0 where a < 3; connection default; --source include/wait_condition.inc connection con2; evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; revoke all privileges on test.* from test2@localhost; drop user test2@localhost; disconnect con2; --echo # --echo # Test that it is possible to KILL a SHOW EXPLAIN command that's waiting --echo # on its target thread --echo # connect (con2, localhost, root,,); connect (con3, localhost, root,,); connection con2; create table t1 (pk int primary key, data char(64)) engine=innodb; insert into t1 select A.a + 10 * B.a + 100 * C.a, 'data1' from t0 A, t0 B, t0 C; --echo # Lock two threads set autocommit=0; select * from t1 where pk between 10 and 20 for update; connection con1; set autocommit=0; # This will freeze send select * from t1 where pk between 10 and 20 for update; # run SHOW EXPLAIN on a frozen thread connection default; let $save_wait_condition= $wait_condition; let $wait_condition= select 1 from information_schema.INNODB_LOCK_WAITS where requesting_trx_id=(select trx_id from information_schema.INNODB_TRX where trx_mysql_thread_id=$thr2); let $thr_default=`select connection_id()`; --source include/wait_condition.inc --echo # do: send_eval show explain for thr2; --disable_query_log send_eval show explain for $thr2; --enable_query_log # kill the SHOW EXPLAIN command connection con3; let $wait_condition= select State='show explain' from information_schema.processlist where id=$thr_default; --source include/wait_condition.inc evalp kill query $thr_default; connection default; # This may fail when using valgrind --error ER_QUERY_INTERRUPTED reap; connection con2; rollback; connection con1; reap; drop table t1; disconnect con3; disconnect con2; let $wait_condition= $save_wait_condition; --echo # --echo # Check that the I_S table is invisible --echo # select table_name from information_schema.tables where table_schema='information_schema' and table_name like '%explain%'; --echo # --echo # MDEV-325: SHOW EXPLAIN: Plan produced by SHOW EXPLAIN is different from standard EXPLAIN: type ALL vs 'index_merge'.. --echo # CREATE TABLE t1 (a INT, b INT, KEY(a), KEY(b)) ENGINE=MyISAM; INSERT INTO t1 VALUES (8,0),(128,5050),(5372,8),(234,7596),(2,0),(2907,8930),(1,0), (0,5224),(8,7638),(960,5),(9872,1534),(0,2295),(3408,9809), (7,0),(1168,0),(2089,5570),(0,205),(88,1018),(0,26528), (0,0),(4,5567),(1444,145),(6,0),(1,7535),(7793,534),(70,9), (178,1),(44,5),(189,0),(3,0); EXPLAIN SELECT a+SLEEP(0.01) FROM t1 WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129 ORDER BY b; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; --send SELECT a+SLEEP(0.01) FROM t1 WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129 ORDER BY b; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_do_select'; --send SELECT a+SLEEP(0.01) FROM t1 WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129 ORDER BY b; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; drop table t1; --echo # --echo # MDEV-298: SHOW EXPLAIN: Plan returned by SHOW EXPLAIN only contains --echo # 'Using temporary' while the standard EXPLAIN says 'Using temporary; Using filesort' --echo # CREATE TABLE t1 (a INT); INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9), (10),(11),(12),(13),(14),(15),(16); INSERT INTO t1 SELECT t11.a FROM t1 t11, t1 t12, t1 t13; EXPLAIN SELECT a FROM t1 GROUP BY a; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; --send SELECT a FROM t1 GROUP BY a; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; drop table t1; --echo # --echo # MDEV-408: SHOW EXPLAIN: Some values are chopped off in SHOW EXPLAIN output --echo # CREATE TABLE t1 (a INT, b VARCHAR(35)) ENGINE=InnoDB; INSERT INTO t1 VALUES (3989,'Abilene'),(3873,'Akron'); CREATE TABLE t2 (c INT, d VARCHAR(52) PRIMARY KEY, KEY(c)) ENGINE=InnoDB; INSERT INTO t2 VALUES (86,'English'),(87,'Russian'); explain SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's'; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; --send SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's'; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; drop table t1, t2; --echo # --echo # MDEV-412: SHOW EXPLAIN: Server crashes in JOIN::print_explain on a query with inner join and ORDER BY the same column twice --echo # CREATE TABLE t1 (a INT PRIMARY KEY, b VARCHAR(3), KEY(b)) ENGINE=MyISAM; INSERT INTO t1 VALUES (3795,'USA'),(3913,'USA'),(3846,'ITA'),(4021,'USA'),(4005,'RUS'),(4038,'USA'), (3825,'USA'),(3840,'USA'),(3987,'USA'),(3807,'USA'),(3896,'USA'),(4052,'USA'), (3973,'USA'),(3982,'ITA'),(3965,'USA'),(3852,'RUS'),(4006,'USA'),(3800,'USA'), (4020,'USA'),(4040,'USA'),(3916,'USA'),(3817,'USA'),(3885,'USA'),(3802,'USA'), (4009,'ITA'),(3895,'USA'),(3963,'RUS'),(4045,'USA'),(3988,'USA'),(3815,'USA'), (4063,'USA'),(3978,'USA'),(4019,'USA'),(3954,'USA'),(3950,'USA'),(3974,'ITA'), (4054,'USA'),(4061,'RUS'),(3976,'USA'),(3966,'USA'),(3957,'USA'),(3981,'USA'), (3923,'USA'),(3876,'USA'),(3819,'USA'),(3877,'USA'),(3829,'ITA'),(3964,'USA'), (4053,'RUS'),(3917,'USA'),(3874,'USA'),(4023,'USA'),(4001,'USA'),(3872,'USA'), (3890,'USA'),(3962,'USA'),(3886,'USA'),(4026,'ITA'),(3869,'USA'),(3937,'RUS'), (3975,'USA'),(3944,'USA'),(3908,'USA'),(3867,'USA'),(3947,'USA'),(3838,'USA'), (3796,'USA'),(3893,'USA'),(3920,'ITA'),(3994,'USA'),(3875,'RUS'),(4011,'USA'), (4013,'USA'),(3810,'USA'),(3834,'USA'),(3968,'USA'),(3931,'USA'),(3839,'USA'), (4042,'USA'),(4039,'ITA'),(3811,'USA'),(3837,'RUS'),(4041,'USA'),(3884,'USA'), (3894,'USA'),(3879,'USA'),(3942,'USA'),(3959,'USA'),(3814,'USA'),(4044,'USA'), (3971,'ITA'),(3823,'USA'),(3793,'RUS'),(3855,'USA'),(3905,'USA'),(3865,'USA'), (4046,'USA'),(3990,'USA'),(4022,'USA'),(3833,'USA'),(3918,'USA'),(4064,'ITA'), (3821,'USA'),(3836,'RUS'),(3921,'USA'),(3914,'USA'),(3888,'USA'); CREATE TABLE t2 (c VARCHAR(3) PRIMARY KEY) ENGINE=MyISAM; INSERT INTO t2 VALUES ('USA'); CREATE TABLE t3 (d VARCHAR(3), e VARCHAR(52), PRIMARY KEY (d,e)) ENGINE=MyISAM; INSERT INTO t3 VALUES ('JPN','Japanese'),('KOR','Korean'),('POL','Polish'),('PRT','Portuguese'), ('ESP','Spanish'),('FRA','French'),('VNM','Vietnamese'); explain SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_do_select'; send SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t1,t2,t3; --echo # --echo # MDEV-423: SHOW EXPLAIN: 'Using where' for a subquery is shown in EXPLAIN, but not in SHOW EXPLAIN output --echo # CREATE TABLE t1 (a INT) ENGINE=MyISAM; INSERT INTO t1 VALUES (7),(0),(9),(3),(4),(2),(5),(7),(0),(9),(3),(4),(2),(5); CREATE TABLE t2 (b INT, c INT) ENGINE=MyISAM; INSERT INTO t2 VALUES (0,4),(8,6),(1,3),(8,5),(9,3),(24,246),(6,2),(1,9),(6,3),(2,8), (4,1),(8,8),(4,8),(4,5),(7,7),(4,5),(1,1),(9,6),(4,2),(8,9); create table t3 like t2; insert into t3 select * from t2; explain SELECT max(a+b+c) FROM t1 AS alias1, ( SELECT * FROM t2 ) AS alias WHERE EXISTS ( SELECT * FROM t3 WHERE b = c ) OR a <= 10; set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send SELECT max(a+b+c) FROM t1 AS alias1, ( SELECT * FROM t2 ) AS alias WHERE EXISTS ( SELECT * FROM t3 WHERE b = c ) OR a <= 10; connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t1,t2,t3; --echo # --echo # MDEV-416: Server crashes in SQL_SELECT::cleanup on EXPLAIN with SUM ( DISTINCT ) in a non-correlated subquery (5.5-show-explain tree) --echo # CREATE TABLE t1 (a INT); INSERT INTO t1 VALUES (1),(2); CREATE TABLE t2 (b INT); INSERT INTO t2 VALUES (8),(9); EXPLAIN SELECT * FROM t1 WHERE ( 8, 89 ) IN ( SELECT b, SUM( DISTINCT b ) FROM t2 GROUP BY b ); DROP TABLE t1,t2; --echo # --echo # Check if queries in non-default charsets work. --echo # set names cp1251; # The below are two Russian letters with codes E3FB in cp1251 encoding. select charset('ãû'); select hex('ãû'); set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send select * from t0 where length('ãû') = a; connection default; set names utf8; --source include/wait_condition.inc evalp show explain for $thr2; set names default; connection con1; # The constant should be two letters, the last looking like 'bl' reap; SET debug_dbug=@old_debug; set names default; --echo # --echo # MDEV-462: SHOW EXPLAIN: Assertion `table_list->table' fails in find_field_in_table_ref if FOR contains a non-numeric value --echo # --error ER_SET_CONSTANTS_ONLY show explain for foo; --echo # --echo # MDEV-411: SHOW EXPLAIN: For dependent subquery EXPLAIN produces type=index, key, 'Using where; Using index', --echo # while SHOW EXPLAIN says type=ALL, no key, 'Range checked for each record' --echo # CREATE TABLE t1 (a INT NOT NULL, KEY(a)) ENGINE=MyISAM; INSERT INTO t1 VALUES (7),(0); CREATE TABLE t2 (b INT NOT NULL) ENGINE=MyISAM; INSERT INTO t2 VALUES (0),(8); explain SELECT SUM(b) FROM ( SELECT * FROM t1 ) AS alias1, t2 WHERE b <= ANY ( SELECT a FROM t1 WHERE a = b + SLEEP(0.2) OR a >= ( SELECT SUM(b) FROM t2 )); set @show_explain_probe_select_id=1; SET debug_dbug='+d,show_explain_probe_join_exec_start'; send SELECT SUM(b) FROM ( SELECT * FROM t1 ) AS alias1, t2 WHERE b <= ANY ( SELECT a FROM t1 WHERE a = b + SLEEP(0.2) OR a >= ( SELECT SUM(b) FROM t2 )); connection default; --source include/wait_condition.inc evalp show explain for $thr2; connection con1; reap; SET debug_dbug=@old_debug; DROP TABLE t1,t2; drop table t0; --echo # --echo # MDEV-5148: Server crashes in print_explain on killing EXPLAIN EXTENDED --echo # create table t0 (a int not null); insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t1 (a int, b int); insert into t1 select a,a from t0; create table t2 as select * from t1; set @show_explain_probe_select_id=2; SET debug_dbug='+d,show_explain_probe_best_ext_lim_search'; send explain select * from t0 where not exists ( select 1 from t1, t2 where t1.b=t2.b and t2.a=t0.a) and a is null; connection default; --source include/wait_condition.inc evalp kill query $thr2; connection con1; --error ER_QUERY_INTERRUPTED reap; drop table t0,t1,t2; --echo # --echo # MDEV-28124: Server crashes in Explain_aggr_filesort::print_json_members --echo # upon SHOW ANALYZE/EXPLAIN FORMAT=JSON --echo # let $wait_condition= select State='show_explain_trap' from information_schema.processlist where id=$thr2; connection con1; set @show_explain_probe_query= 'SELECT count(*) - count(*) FROM sys.waits_by_user_by_latency'; set debug_dbug='+d,explain_notify_tables_are_closed'; # Statement guarantees to produce 0 on every run send SELECT count(*) - count(*) FROM sys.waits_by_user_by_latency; connection default; --source include/wait_condition.inc --error ER_TARGET_NOT_EXPLAINABLE evalp SHOW EXPLAIN FOR $thr2; connection con1; reap; --echo # End connection default; disconnect con1; set debug_sync='RESET';