Collect information about prepared statements if P_S is enabled

[Sveta Smirnova]

In version 5.7+ it is possible to see statistics of all prepared statements, currently existing in the server:

select t.processlist_id, pse.* from performance_schema.prepared_statements_instances pse join performance_schema.threads t on (pse.OWNER_THREAD_ID=t.thread_id);

[Agustín (agustin-gallego)]

For tests.

SET @sum_statement_prepare = 'SELECT SUM(? + ?) AS sum_A_B';
PREPARE sum_statement FROM @sum_statement_prepare;

SET @random_statement_prepare = 'SELECT RAND() AS rand';
PREPARE rand_statement FROM @random_statement_prepare;
EXECUTE rand_statement;
DEALLOCATE PREPARE rand_statement;

SET @absolute_value_statement_prepare = 'SELECT ABS(?), sleep(10) AS abs_A';
PREPARE abs_statement FROM @absolute_value_statement_prepare;
SET @a = -5;
EXECUTE abs_statement USING @a;

-- DEALLOCATE PREPARE sum_statement;
-- DEALLOCATE PREPARE abs_statement;

[Agustín (agustin-gallego)]

https://github.com/percona/percona-toolkit/pull/190

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PT-1395