#
# Test that no intermediate states during "ANALYZE TABLE" execution is exposed to other threads.
#
--source include/have_innodb.inc
#--source include/have_debug_sync.inc

# Disable background stats recalculation.
SET @innodb_stats_auto_recalc_save = @@innodb_stats_auto_recalc;
SET GLOBAL innodb_stats_auto_recalc = OFF;

# Reset "Sort_merge_passes" to 0
FLUSH STATUS;

SET SESSION long_query_time=0;
SET SESSION min_examined_row_limit=0;
SET SESSION sort_buffer_size=32804;

CREATE TABLE t1 (a INT) ENGINE=InnoDB;
INSERT INTO t1 VALUES (5), (16), (2), (17), (1);
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;

ANALYZE TABLE t1;

# Execute "SELECT" statement and capture "Sort_merge_Passes" from status.
--disable_result_log
SELECT * FROM t1 ORDER BY a;
--enable_result_log

# Here we expect "Sort_merge_passes" to be increased by 4 (to be set to 0 + 4 = 4)
SHOW SESSION STATUS LIKE 'Sort_merge_passes';

# Initiate another connection and make "ANALYZE TABLE" stop at
# "dict_stats_analyze_index_middle" debug sync point.
connect (auxcon,localhost,root,,);

--echo Connection Aux
connection auxcon;
SET DEBUG_SYNC = 'RESET';
SET DEBUG_SYNC = 'dict_stats_analyze_index_middle WAIT_FOR initiated';
--send ANALYZE TABLE t1

# Return to primary connection and run "SELECT" statement again.
# Then capture "Sort_merge_Passes" from status again.
--echo Connection Default
--sleep 2
connection default;
--disable_result_log
SELECT * FROM t1 ORDER BY a;
--enable_result_log

# Here we expect "Sort_merge_passes" to be increased by 4 again (to be set to 4 + 4 = 8).
# However, because "ANALYZE TABLE" in another connection is stopped at debug sync point,
# stats for this table indexes were reset but have not been updated to new values yet.
# Nevertheless, they are visible to another thread which executes
# "SELECT * FROM t1 ORDER BY a" statement and which depends on current value of the
# "stat_n_leaf_pages" (which was reset to 1). This gives us unexpected increase in
# "Sort_merge_passes" (4 + 6 = 10, in this particular case).
# we get different 
SHOW SESSION STATUS LIKE 'Sort_merge_passes';

# Resume "ANALYZE TABLE" execution in the auxiliary connection.
SET DEBUG_SYNC ='now SIGNAL initiated';

# Swithch to auxiliary connection and wait for "ANALYZE TABLE" statement to finish.
--echo Connection Aux
connection auxcon;
--reap

# Drop auxiliary connection.
--echo Connection Default
connection default;

disconnect auxcon;

SET SESSION long_query_time=default;
SET SESSION min_examined_row_limit=default;
SET SESSION sort_buffer_size=default;

DROP TABLE t1;

SET GLOBAL innodb_stats_auto_recalc = @innodb_stats_auto_recalc_save;