--source include/have_innodb.inc

if (`SELECT $PS_PROTOCOL + $CURSOR_PROTOCOL > 0`)
{
   --skip Need regular protocol but ps-protocol and cursor-protocol were specified
}

SET @save_storage_engine= @@default_storage_engine;
SET default_storage_engine= InnoDB;

--echo #
--echo # MDEV-16708: Unsupported commands for prepared statements
--echo #

--echo # Disable ps-protocol explicitly in order to test support of
--echo # prepared statements for use case when statements passed
--echo # to the server via text client-server protocol (in contrast
--echo # with binary protocol used in the test file
--echo # ps_missed_cmds_bin_prot.test)
--disable_ps_protocol

--echo # Test case 1: Check that the statement 'LOAD DATA' is supported
--echo # by prepared statements

--echo # First, set up environment for use by the 'LOAD DATA' statement
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1);
COMMIT;
SELECT * INTO OUTFILE 'load.data' FROM t1;

PREPARE stmt_1 FROM "LOAD DATA INFILE 'load.data' INTO TABLE t1";
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'LOAD DATA' statement
--echo # were damaged.
EXECUTE stmt_1;
SELECT * FROM t1;
--echo # Clean up
DEALLOCATE PREPARE stmt_1;
DROP TABLE t1;
--let $datadir= `select @@datadir`
--remove_file $datadir/test/load.data

--echo # Test case 2: Check that the 'LOCK TABLE', 'UNLOCK TABLES' statements
--echo # are supported by prepared statements
CREATE TABLE t1 (a INT);

PREPARE stmt_1 FROM "LOCK TABLE t1 READ";
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'LOCK TABLE READ'
--echo # statement were damaged.
EXECUTE stmt_1;

PREPARE stmt_1 FROM "UNLOCK TABLE";
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'UNLOCK TABLE' statement
--echo # were damaged.
EXECUTE stmt_1;

PREPARE stmt_1 FROM "LOCK TABLE t1 WRITE";
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'LOCK TABLE WRITE'
--echo # statement were damaged.
EXECUTE stmt_1;
--echo # Clean up
DEALLOCATE PREPARE stmt_1;
UNLOCK TABLE;
DROP TABLE t1;

--echo # Test case 3: Check that the 'USE' statement is supported by
--echo # prepared statements
--disable_service_connection
CREATE DATABASE mdev_16708_db;
PREPARE stmt_1 FROM 'USE mdev_16708_db';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'USE' statement
--echo # were damaged.
EXECUTE stmt_1;

--echo # Check that the current database has been changed
SELECT DATABASE();

--echo # Clean up
DEALLOCATE PREPARE stmt_1;
USE test;
DROP DATABASE mdev_16708_db;
--enable_service_connection
--echo # Test case 4: Check that the 'ALTER DATABASE' statement is supported
--echo # by prepared statements
CREATE DATABASE mdev_16708_db;
PREPARE stmt_1 FROM "ALTER DATABASE mdev_16708_db COMMENT 'New comment'";
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'ALTER DATABASE' statement
--echo # were damaged.
EXECUTE stmt_1;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;
USE test;
DROP DATABASE mdev_16708_db;

--echo # Test case 5: Check that the 'CREATE FUNCTION/ALTER FUNCTION/
--echo # DROP FUNCTION' statements are supported by prepared statements
PREPARE stmt_1 FROM 'CREATE FUNCTION f1() RETURNS INT RETURN 1';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'CREATE FUNCTION'
--echo # statement were damaged. The second attempt to execute the prepared
--echo # statement stmt_1 results in error ER_SP_ALREADY_EXISTS since
--echo # the stored function f() has been created on first run of stmt1.
--error ER_SP_ALREADY_EXISTS
EXECUTE stmt_1;

PREPARE stmt_1 FROM 'ALTER FUNCTION f1 SQL SECURITY INVOKER';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'ALTER FUNCTION'
--echo # statement were damaged.
EXECUTE stmt_1;

PREPARE stmt_1 FROM 'DROP FUNCTION f1';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling 'DROP FUNCTION' statement
--echo # were damaged. The second attempt to run 'DROP FUNCTION f1' using
--echo # prepared statement expectedly results in issuing the error
--echo # ER_SP_DOES_NOT_EXIST since the stored function was dropped on first
--echo # executuon of the prepared statement stmt_1.
--error ER_SP_DOES_NOT_EXIST
EXECUTE stmt_1;

--echo # Test case 6: Check that the 'CHECK TABLE' statement is supported
--echo # by prepared statements
CREATE TABLE t1 (a INT);
PREPARE stmt_1 FROM 'CHECK TABLE t1';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'CHECK TABLE' statement
--echo # were damaged.
EXECUTE stmt_1;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;
DROP TABLE t1;

--echo # Test case 7: Check that the BEGIN/SAVEPOINT/RELEASE SAVEPOINT
--echo # statements are supported by prepared statements

--disable_view_protocol
--echo # Set up environmentr for the test case
CREATE TABLE t1 (a INT);

PREPARE stmt_1 FROM 'BEGIN';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'BEGIN' statement
--echo # were damaged.
EXECUTE stmt_1;

INSERT INTO t1 VALUES (1);
--echo # Run 'SAVEPOINT s1' using prepared statements
PREPARE stmt_2 FROM 'SAVEPOINT s1';
EXECUTE stmt_2;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'SAVEPOINT' statement
--echo # were damaged.
EXECUTE stmt_2;

INSERT INTO t1 VALUES (2);
--echo # Expected rows: '1' and '2'
SELECT * FROM t1;
--echo # Rollback the last row inserted ('2')
ROLLBACK TO SAVEPOINT s1;
--echo # Expected output from t1 after transaction has been rolled back
--echo # to the savepoint is '1'. If it is case then the statement SAVEPOINT
--echo # was handled successfully with prepared statement
SELECT * FROM t1;

PREPARE stmt_3 FROM 'RELEASE SAVEPOINT s1';
EXECUTE stmt_3;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'RELEASE' statement
--echo # were damaged. The second attempt to release the same savepoint
--echo # expectedly lead to error 'SAVEPOINT s1 does not exist'
--echo # that's just ignored.
--error ER_SP_DOES_NOT_EXIST
EXECUTE stmt_3;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;
DEALLOCATE PREPARE stmt_2;
DEALLOCATE PREPARE stmt_3;
DROP TABLE t1;
--enable_view_protocol

--echo # Test case 8: Check that the 'PURGE BINARY LOGS BEFORE' statement
--echo # is supported by prepared statements
PREPARE stmt_1 FROM "PURGE BINARY LOGS BEFORE '2020-11-17'";
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'PURGE BINARY LOGS BEFORE'
--echo # statement were damaged.
EXECUTE stmt_1;

--echo # Check that the 'PURGE BINARY LOGS TO' statement is supported by
--echo # prepared statements
PREPARE stmt_1 FROM "PURGE BINARY LOGS TO 'mariadb-bin.000063'";
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'PURGE BINARY LOGS TO'
--echo # statement were damaged.
EXECUTE stmt_1;

--echo # Test case 9: Check that the 'HANDLER OPEN/HANDLER READ/
--echo # HANDLER CLOSE' statements are supported by prepared statements
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1);
INSERT INTO t1 VALUES (1);
COMMIT;

PREPARE stmt_1 FROM 'HANDLER t1 OPEN';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'HANDLER OPEN'
--echo # statement were damaged. Execution of this statement the second
--echo # time expectedly results in emitting the error ER_NONUNIQ_TABLE.
--echo # The same error is issued in case the statement 'HANDLER t1 OPEN' is
--echo # executed twice using a regular statement.
--error ER_NONUNIQ_TABLE
EXECUTE stmt_1;

PREPARE stmt_2 FROM 'HANDLER t1 READ FIRST';
PREPARE stmt_3 FROM 'HANDLER t1 READ NEXT';
PREPARE stmt_4 FROM 'HANDLER t1 CLOSE';

EXECUTE stmt_2;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'HANDLER READ FIRST'
--echo # statement were damaged.
EXECUTE stmt_2;

EXECUTE stmt_3;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'HANDLER READ NEXT'
--echo # statement were damaged.
EXECUTE stmt_3;

EXECUTE stmt_4;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'HANDLER CLOSE'
--echo # statement were damaged. Execution of this statement the second
--echo # time results in emitting the error ER_UNKNOWN_TABLE. The same error
--echo # is issued in case the statement 'HANDLER t1 CLOSE' executed twice
--echo # using a regular statement.
--error ER_UNKNOWN_TABLE
EXECUTE stmt_4;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;
DEALLOCATE PREPARE stmt_2;
DEALLOCATE PREPARE stmt_3;
DEALLOCATE PREPARE stmt_4;
DROP TABLE t1;

--echo # Test case 10: Check that the HELP statement
--echo # is supported by prepared statements
# avoid existing articles that may get updated.
INSERT INTO mysql.help_topic VALUES (0, 'Tamagotchi', 0, 'This digital pet is not a KB article', 'no example', 'https://tamagotchi.com/');
PREPARE stmt_1 FROM "HELP `Tamagotchi`";
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'HELP' statement
--echo # were damaged.

EXECUTE stmt_1;
DELETE FROM mysql.help_topic WHERE help_topic_id = 0;

--echo # Test case 11: Check that the 'CREATE PROCEDURE' statement
--echo # is supported by prepared statements
PREPARE stmt_1 FROM 'CREATE PROCEDURE p1() SET @a=1';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'CREATE PROCEDURE'
--echo # statement were damaged. Execution of this statement the second
--echo # time expectedly results in emitting the error ER_SP_ALREADY_EXISTS.
--echo # The same error is issued in case the 'HANDLER t1 OPEN' statement
--echo # is executed twice using a regular statement.
--error ER_SP_ALREADY_EXISTS
EXECUTE stmt_1;

--echo # Test case 12: Check that the 'ALTER PROCEDURE' statement is supported
--echo # by prepared statements.
# This test case relies on artefacts of the test case 11 (the procedure p1)

PREPARE stmt_1 FROM 'ALTER PROCEDURE p1 SQL SECURITY INVOKER';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'ALTER PROCEDURE'
--echo # statement were damaged.
EXECUTE stmt_1;

--echo # Test case 13: Check that the 'DROP PROCEDURE' statement is supported
--echo # by prepared statements.
# This test case relies on artefacts of the test case 11 (the procedure p1)
PREPARE stmt_1 FROM 'DROP PROCEDURE p1';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'DROP PROCEDURE' statement
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error ER_SP_DOES_NOT_EXIST.

--error ER_SP_DOES_NOT_EXIST
EXECUTE stmt_1;

--echo # Test case 14: Check that the 'CALL' statement is supported
--echo # by prepared statements.

CREATE PROCEDURE p1() SET @a=1;
PREPARE stmt_1 FROM 'CALL p1()';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'CALL' statement
--echo # were damaged.
EXECUTE stmt_1;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;
DROP PROCEDURE p1;

--echo # Test case 15: Check that the 'CREATE VIEW' statement can be executed
--echo # as a prepared statement.
--echo # Create environment for the test case
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1);
COMMIT;

PREPARE stmt_1 FROM 'CREATE VIEW v1 AS SELECT * FROM t1';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'CREATE VIEW'
--echo # statement were damaged. The second execution of the prepared
--echo # statement stmt_1 results in error ER_TABLE_EXISTS_ERROR since
--echo # the view v1 does already exist. It is expected behaviour.

--error ER_TABLE_EXISTS_ERROR
EXECUTE stmt_1;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;

DROP VIEW v1;
DROP TABLE t1;

--echo # Test case 16: Check that the 'CREATE TRIGGER' statement can be executed
--echo # as a prepared statement.
CREATE TABLE t1 (a INT);
PREPARE stmt_1 FROM 'CREATE TRIGGER trg1 BEFORE INSERT ON t1 FOR EACH ROW SET @a=1';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'CREATE VIEW' statement
--echo # were damaged. The second execution of the prepared statement stmt_1
--echo # results in error ER_TRG_ALREADY_EXISTS since the trigger trg1 does
--echo # already exist. It is expected behaviour.
--error ER_TRG_ALREADY_EXISTS
EXECUTE stmt_1;

--echo # Test case 17: Check that the 'DROP TRIGGER' statement can be executed
--echo # as a prepared statement.
--echo # This test relies on presence of the trigger trg1 created by
--echo # the test case 16.
PREPARE stmt_1 FROM 'DROP TRIGGER trg1';
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'DROP TRIGGER' statement
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error ER_TRG_DOES_NOT_EXIST.
--error ER_TRG_DOES_NOT_EXIST
EXECUTE stmt_1;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;
DROP TABLE t1;

--echo # Test case 18: Check that XA related SQL statements can be executed
--echo # as prepared statements.
--echo # Create the table t1 used by XA transaction.
CREATE TABLE t1 (a INT);
PREPARE stmt_1 FROM "XA START 'xid1'";
PREPARE stmt_2 FROM "XA END 'xid1'";
PREPARE stmt_3 FROM "XA PREPARE 'xid1'";
PREPARE stmt_4 FROM "XA RECOVER";
PREPARE stmt_5 FROM "XA COMMIT 'xid1'";
PREPARE stmt_6 FROM "XA ROLLBACK 'xid1'";

--echo # Start a new XA transaction
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'XA START' statement
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error XAER_RMFAIL since there is active
--echo # XA transaction that has just been already.
--error ER_XAER_RMFAIL
EXECUTE stmt_1;

INSERT INTO t1 VALUES (1);

--echo # End the current XA transaction
EXECUTE stmt_2;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'XA END' statement
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error XAER_RMFAIL since the XA transaction
--echo # with XID 'xid1' has been already ended.
--error ER_XAER_RMFAIL
EXECUTE stmt_2;

--echo # Prepare the current XA transaction for finalization
EXECUTE stmt_3;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'XA END' statement
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error XAER_RMFAIL since the XA transaction
--echo # with XID 'xid1' has been already ended.
--error ER_XAER_RMFAIL
EXECUTE stmt_3;

--echo # Run XA RECOVER as a prepared statement
EXECUTE stmt_4;
--echo # And execute it yet another time to check that no internal structures
--echo # used for handling the statement 'XA RECOVER' were damaged.
EXECUTE stmt_4;

--echo # Commit the current XA transaction
EXECUTE stmt_5;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'XA COMMIT' statement
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error XAER_NOTA since the XA transaction
--echo # with XID 'xid1' has been finalized and no more exists.
--error ER_XAER_NOTA
EXECUTE stmt_5;

--echo # Query the table t1 to check that it contains a record inserted by
--echo # the XA transaction just finished.
SELECT * FROM t1;

--echo # Using prepared statements start a new XA transaction, INSERT a row
--echo # into the table t1, prepare the XA transaction and rollback it.
--echo # This use case is similar to precedence one except it does rollback
--echo # XA transaction instead commit it. Therefore every prepared statement
--echo # is executed only once except the last XA ROLLBACK.

--echo # Start a new XA transaction
EXECUTE stmt_1;

INSERT INTO t1 VALUES (1);

--echo # End the current XA transaction
EXECUTE stmt_2;

--echo # Prepare the current XA transaction for finalization
EXECUTE stmt_3;

--echo # Rolback the current XA transaction
EXECUTE stmt_6;

--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the statement 'XA ROLLBACK'
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error XAER_NOTA since the XA transaction
--echo # with XID 'xid1' has been finalized and no more exists.
--error ER_XAER_NOTA
EXECUTE stmt_6;

--echo # Clean up
DROP TABLE t1;
DEALLOCATE PREPARE stmt_1;
DEALLOCATE PREPARE stmt_2;
DEALLOCATE PREPARE stmt_3;
DEALLOCATE PREPARE stmt_4;
DEALLOCATE PREPARE stmt_5;
DEALLOCATE PREPARE stmt_6;

--echo # Test case 19: Check that the  CREATE SERVER/ALTER SERVER/DROP SERVER
--echo # statements can be executed as prepared statements.

PREPARE stmt_1 FROM "CREATE SERVER s FOREIGN DATA WRAPPER mysql OPTIONS (USER 'u1', HOST '127.0.0.1')";
PREPARE stmt_2 FROM "ALTER SERVER s OPTIONS (USER 'u2')";
PREPARE stmt_3 FROM "DROP SERVER s";

EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'CREATE SERVER' statement
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error ER_FOREIGN_SERVER_EXISTS
--echo # since a server with same has just been created.
--error ER_FOREIGN_SERVER_EXISTS
EXECUTE stmt_1;

EXECUTE stmt_2;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'ALTER SERVER' statement
--echo # were damaged.
EXECUTE stmt_2;

EXECUTE stmt_3;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'DROP SERVER' statement
--echo # were damaged. Execution of this statement the second time expectedly
--echo # results in emitting the error ER_FOREIGN_SERVER_DOESNT_EXIST
--echo # since the server with same has just been dropped.
--error ER_FOREIGN_SERVER_DOESNT_EXIST
EXECUTE stmt_3;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;
DEALLOCATE PREPARE stmt_2;
DEALLOCATE PREPARE stmt_3;

--echo # Test case 21: Check that the SIGNAL and RESIGNAL statements
--echo # can be executed as a prepared statement
PREPARE stmt_1 FROM "SIGNAL SQLSTATE '45000' SET MYSQL_ERRNO=30001, MESSAGE_TEXT='Hello, world!'";
--error 30001
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'SIGNAL' statement
--echo # were damaged.
--error 30001
EXECUTE stmt_1;

PREPARE stmt_1 FROM 'RESIGNAL SET MYSQL_ERRNO = 5';
--error ER_RESIGNAL_WITHOUT_ACTIVE_HANDLER
EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'RESIGNAL' statement
--echo # were damaged.
--error ER_RESIGNAL_WITHOUT_ACTIVE_HANDLER
EXECUTE stmt_1;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;

--echo # Test case 23: Check the 'GET DIAGNOSTICS' statement
--echo # can be executed as a prepared statement
PREPARE stmt_1 FROM 'GET DIAGNOSTICS CONDITION 1 @sqlstate = RETURNED_SQLSTATE, @errno = MYSQL_ERRNO, @text = MESSAGE_TEXT';

--echo # Query from non existent table to fill the diagnostics area
--echo # with information
--error ER_NO_SUCH_TABLE
SELECT * FROM non_existent_table_1;
EXECUTE stmt_1;
--echo # Check that information from diagnostics area has been retrieved
SELECT @sqlstate, @errno, @text;

--error ER_NO_SUCH_TABLE
SELECT * FROM non_existent_table_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the
--echo # 'GET DIAGNOSTICS CONDITION' statement were damaged.
EXECUTE stmt_1;

--echo # Clean up
DEALLOCATE PREPARE stmt_1;

--echo # Test case 24: Check the statements 'BACKUP'/'BACKUP UNLOCK'
--echo # can be executed as a prepared statement
CREATE TABLE t1 (a INT);
PREPARE stmt_1 FROM 'BACKUP LOCK t1';
PREPARE stmt_2 FROM 'BACKUP UNLOCK';

EXECUTE stmt_1;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'BACKUP LOCK'
--echo # statement were damaged.
EXECUTE stmt_1;

EXECUTE stmt_2;
--echo # Execute the same prepared statement the second time to check that
--echo # no internal structures used for handling the 'BACKUP UNLOCK'
--echo # statement were damaged.
EXECUTE stmt_2;

--echo # Clean up
DROP TABLE t1;
DEALLOCATE PREPARE stmt_1;
DEALLOCATE PREPARE stmt_2;

--enable_ps_protocol
SET default_storage_engine= @save_storage_engine;