#
# Test that the table option STATS_SAMPLE_PAGES=N|default is indeed
# used by InnoDB
#

-- source include/have_innodb.inc
# Page numbers printed by this test depend on the page size
-- source include/have_innodb_16k.inc

SET GLOBAL innodb_stats_persistent_sample_pages=17;

CREATE TABLE test_ps_sample_pages_used (
	a VARCHAR(512), PRIMARY KEY (a)
) ENGINE=INNODB STATS_SAMPLE_PAGES=default;

# Insert enough records into the table so that it has more than 2*17+1 pages
# If we ask to scan more than the half of the leaf pages, then the sampling
# will do full scan and we cannot check whether the sample_pages variable was
# honored.
BEGIN;
-- disable_query_log
let $i=999;
while ($i) {
	eval INSERT INTO test_ps_sample_pages_used VALUES (REPEAT(1000+$i, 128));
	dec $i;
}
-- enable_query_log
COMMIT;

ANALYZE TABLE test_ps_sample_pages_used;

# confirm the big number of leaf pages in the index
SELECT stat_name, stat_value FROM mysql.innodb_index_stats
WHERE table_name='test_ps_sample_pages_used' AND stat_name='n_leaf_pages';

# confirm that 17 pages were sampled, that is - the global
# innodb_stats_persistent_sample_pages is used when the table option
# STATS_SAMPLE_PAGES is set to 'default'.
SELECT sample_size FROM mysql.innodb_index_stats
WHERE table_name='test_ps_sample_pages_used' AND stat_name='n_diff_pfx01';

ALTER TABLE test_ps_sample_pages_used STATS_SAMPLE_PAGES=14;

ANALYZE TABLE test_ps_sample_pages_used;

# confirm that 14 pages were sampled, that is - the table option
# STATS_SAMPLE_PAGES is used when it is set.
SELECT sample_size FROM mysql.innodb_index_stats
WHERE table_name='test_ps_sample_pages_used' AND stat_name='n_diff_pfx01';

DROP TABLE test_ps_sample_pages_used;

SET GLOBAL innodb_stats_persistent_sample_pages=default;
