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382e81ca84
select tables optimized away - Take into account, that for some degenerate joins instead of "join->table_count=0" the code sets "join->tables_list=0".
454 lines
12 KiB
Text
454 lines
12 KiB
Text
#
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# Tests for SHOW EXPLAIN FOR functionality
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#
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--source include/have_debug.inc
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--disable_warnings
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drop table if exists t0, t1, t2;
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drop view if exists v1;
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--enable_warnings
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#
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# Testcases in this file do not work with embedded server. The reason for this
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# is that we use the following commands for synchronization:
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#
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# set @show_explain_probe_select_id=1;
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# set debug='d,show_explain_probe_1';
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# send select count(*) from t1 where a < 100000;
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#
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# When ran with mysqltest_embedded, this translates into:
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#
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# Thread1> DBUG_PUSH("d,show_explain_probe_1");
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# Thread1> create another thread for doing "send ... reap"
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# Thread2> mysql_parse("select count(*) from t1 where a < 100000");
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#
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# That is, "select count(*) ..." is ran in a thread for which DBUG_PUSH(...)
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# has not been called. As a result, show_explain_probe_1 does not fire, and
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# "select count(*) ..." does not wait till its SHOW EXPLAIN command, and the
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# test fails.
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#
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-- source include/not_embedded.inc
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create table t0 (a int);
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insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
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create table t1 (a int);
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insert into t1 select A.a + 10*B.a + 100*C.a from t0 A, t0 B, t0 C;
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alter table t1 add b int, add c int, add filler char(32);
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update t1 set b=a, c=a, filler='fooo';
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alter table t1 add key(a), add key(b);
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#
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# Try killing a non-existent thread
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#
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--error ER_NO_SUCH_THREAD
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show explain for 2*1000*1000*1000;
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--error ER_NOT_SUPPORTED_YET
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show explain for (select max(a) from t0);
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#
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# Setup two threads and their ids
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#
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let $thr1=`select connection_id()`;
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connect (con1, localhost, root,,);
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connection con1;
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let $thr2=`select connection_id()`;
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connection default;
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# SHOW EXPLAIN FOR <idle thread>
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--error ER_ERROR_WHEN_EXECUTING_COMMAND
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evalp show explain for $thr2;
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# SHOW EXPLAIN FOR <ourselves>
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--error ER_ERROR_WHEN_EXECUTING_COMMAND
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evalp show explain for $thr1;
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let $wait_condition= select State='show_explain_trap' from information_schema.processlist where id=$thr2;
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#
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# Test SHOW EXPLAIN for simple queries
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#
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connection con1;
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_1';
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send select count(*) from t1 where a < 100000;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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send select max(c) from t1 where a < 10;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo # We can catch EXPLAIN, too.
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set @show_expl_tmp= @@optimizer_switch;
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set optimizer_switch='index_condition_pushdown=on,mrr=on,mrr_sort_keys=on';
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send explain select max(c) from t1 where a < 10;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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set optimizer_switch= @show_expl_tmp;
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--echo # UNION, first branch
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_1';
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send explain select a from t0 A union select a+1 from t0 B;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo # UNION, second branch
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_1';
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send explain select a from t0 A union select a+1 from t0 B;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo # Uncorrelated subquery, select
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_1';
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send select a, (select max(a) from t0 B) from t0 A where a<1;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo # Uncorrelated subquery, explain
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_1';
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send explain select a, (select max(a) from t0 B) from t0 A where a<1;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo # correlated subquery, select
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_1';
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send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo # correlated subquery, explain
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_1';
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send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo # correlated subquery, select, while inside the subquery
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set @show_explain_probe_select_id=2; # <---
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set debug='d,show_explain_probe_1';
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send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo # correlated subquery, explain, while inside the subquery
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set @show_explain_probe_select_id=2;
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set debug='d,show_explain_probe_1';
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send select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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# TODO: explain in the parent subuqery when the un-correlated child has been
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# run (and have done irreversible cleanups)
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# ^^ Is this at all possible after 5.3?
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# Maybe, for 5.3 try this:
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# - run before/after the parent has invoked child's optimization
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# - run after materialization
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--echo # Try to do SHOW EXPLAIN for a query that runs a SET command:
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--echo # I've found experimentally that select_id==2 here...
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--echo #
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set @show_explain_probe_select_id=2;
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set debug='d,show_explain_probe_1';
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send set @foo= (select max(a) from t0 where sin(a) >0);
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connection default;
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--source include/wait_condition.inc
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--error ER_ERROR_WHEN_EXECUTING_COMMAND
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo #
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--echo # Attempt SHOW EXPLAIN for an UPDATE
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--echo #
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create table t2 as select a as a, a as dummy from t0 limit 2;
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set @show_explain_probe_select_id=2;
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set debug='d,show_explain_probe_1';
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send update t2 set dummy=0 where (select max(a) from t0 where t2.a + t0.a <3) >3 ;
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connection default;
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--source include/wait_condition.inc
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--error ER_ERROR_WHEN_EXECUTING_COMMAND
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evalp show explain for $thr2;
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--error ER_ERROR_WHEN_EXECUTING_COMMAND
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evalp show explain for $thr2;
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connection con1;
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reap;
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drop table t2;
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--echo #
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--echo # Attempt SHOW EXPLAIN for a DELETE
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--echo #
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create table t2 as select a as a, a as dummy from t0 limit 2;
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set @show_explain_probe_select_id=2;
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set debug='d,show_explain_probe_1';
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send delete from t2 where (select max(a) from t0 where t2.a + t0.a <3) >3 ;
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connection default;
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--source include/wait_condition.inc
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--error ER_ERROR_WHEN_EXECUTING_COMMAND
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evalp show explain for $thr2;
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--error ER_ERROR_WHEN_EXECUTING_COMMAND
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evalp show explain for $thr2;
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connection con1;
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reap;
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drop table t2;
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--echo #
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--echo # Multiple SHOW EXPLAIN calls for one select
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--echo #
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create table t2 as select a as a, a as dummy from t0 limit 3;
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set @show_explain_probe_select_id=2;
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set debug='d,show_explain_probe_1';
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send select t2.a, ((select max(a) from t0 where t2.a + t0.a <3) >3) as SUBQ from t2;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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evalp show explain for $thr2;
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evalp show explain for $thr2;
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connection con1;
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reap;
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drop table t2;
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--echo #
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--echo # SHOW EXPLAIN for SELECT ... ORDER BY with "Using filesort"
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--echo #
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explain select * from t0 order by a;
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set debug='d,show_explain_probe_1';
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set @show_explain_probe_select_id=1;
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send select * from t0 order by a;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo #
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--echo # SHOW EXPLAIN for SELECT ... with "Using temporary"
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--echo #
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connection default;
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explain select distinct a from t0;
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connection con1;
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set debug='d,show_explain_probe_1';
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set @show_explain_probe_select_id=1;
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send select distinct a from t0;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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--echo #
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--echo # SHOW EXPLAIN for SELECT ... with "Using temporary; Using filesort"
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--echo #
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connection default;
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explain select distinct a from t0;
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connection con1;
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set debug='d,show_explain_probe_1';
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set @show_explain_probe_select_id=1;
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send select distinct a from t0;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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set debug='';
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--echo #
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--echo # MDEV-238: SHOW EXPLAIN: Server crashes in JOIN::print_explain with FROM subquery and GROUP BY
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--echo #
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CREATE TABLE t2 ( a INT );
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INSERT INTO t2 VALUES (1),(2),(1),(4),(2);
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explain SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a;
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set debug='d,show_explain_in_find_all_keys';
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send SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a;
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connection default;
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--source include/wait_condition.inc
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--echo # NOTE: current code will not show "Using join buffer":
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evalp show explain for $thr2;
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connection con1;
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reap;
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set debug='';
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DROP TABLE t2;
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--echo #
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--echo # MDEV-239: Assertion `field_types == 0 ... ' failed in Protocol_text::store(double, uint32, String*) with
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--echo # SHOW EXPLAIN over EXPLAIN EXTENDED
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--echo #
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CREATE TABLE t2 (a INT);
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INSERT INTO t2 VALUES (1),(2),(1),(4),(2);
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EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a ;
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_join_exec_end';
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send EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a ;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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set debug='';
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DROP TABLE t2;
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--echo #
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--echo # MDEV-240: SHOW EXPLAIN: Assertion `this->optimized == 2' failed in
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--echo # JOIN::print_explain on query with a JOIN, TEMPTABLE view,
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--echo #
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CREATE TABLE t3 (a INT);
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CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t3;
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INSERT INTO t3 VALUES (8);
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CREATE TABLE t2 (b INT);
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INSERT INTO t2 VALUES (4),(5),(6),(7),(8),(9);
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explain SELECT * FROM v1, t2;
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set @show_explain_probe_select_id=2;
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set debug='d,show_explain_probe_join_exec_end';
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send SELECT * FROM v1, t2;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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set debug='';
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DROP VIEW v1;
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DROP TABLE t2, t3;
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--echo #
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--echo # MDEV-267: SHOW EXPLAIN: Server crashes in JOIN::print_explain on most of queries
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--echo #
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_join_exec_end';
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send select sleep(1);
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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set debug='';
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--echo #
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--echo # Same as above, but try another reason for JOIN to be degenerate
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--echo #
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_join_exec_end';
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send select * from t0 where 1>10;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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set debug='';
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--echo #
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--echo # Same as above, but try another reason for JOIN to be degenerate (2)
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--echo #
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create table t3(a int primary key);
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insert into t3 select a from t0;
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set @show_explain_probe_select_id=1;
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set debug='d,show_explain_probe_join_exec_end';
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send select * from t0,t3 where t3.a=112233;
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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set debug='';
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drop table t3;
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--echo #
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--echo # MDEV-270: SHOW EXPLAIN: server crashes in JOIN::print_explain on a query with
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--echo # select tables optimized away
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--echo #
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CREATE TABLE t2 (pk INT PRIMARY KEY, a INT ) ENGINE=MyISAM;
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INSERT INTO t2 VALUES
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(1,4),(2,62),(3,7),(4,1),(5,0),(6,7),(7,7),(8,1),(9,7),(10,1),
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(11,5),(12,2),(13,0),(14,1),(15,8),(16,1),(17,1),(18,9),(19,1),(20,5) ;
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explain SELECT * FROM t2 WHERE a =
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(SELECT MAX(a) FROM t2
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WHERE pk= (SELECT MAX(pk) FROM t2 WHERE pk = 3)
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);
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set @show_explain_probe_select_id=2;
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set debug='d,show_explain_probe_do_select';
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send SELECT * FROM t2 WHERE a =
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(SELECT MAX(a) FROM t2
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WHERE pk= (SELECT MAX(pk) FROM t2 WHERE pk = 3)
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);
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connection default;
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--source include/wait_condition.inc
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evalp show explain for $thr2;
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connection con1;
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reap;
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set debug='';
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drop table t2;
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## TODO: Test this: have several SHOW EXPLAIN requests be queued up for a
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## thread and served together.
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drop table t0,t1;
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