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set @save_use_stat_tables = @@use_stat_tables;
set @@use_stat_tables = COMPLEMENTARY;
CREATE TABLE test_ps_fetch
(a INT, b INT, c INT, d INT, PRIMARY KEY (a, b), INDEX idx (c, d))
ENGINE=INNODB STATS_PERSISTENT=1;
ANALYZE TABLE test_ps_fetch;
Table test.test_ps_fetch
Op analyze
Msg_type status
Msg_text Engine-independent statistics collected
Table test.test_ps_fetch
Op analyze
Msg_type status
Msg_text OK
SELECT n_rows, clustered_index_size, sum_of_other_index_sizes
FROM mysql.innodb_table_stats WHERE table_name = 'test_ps_fetch';
n_rows 0
clustered_index_size 1
sum_of_other_index_sizes 1
SELECT index_name, stat_name, stat_value, sample_size, stat_description
FROM mysql.innodb_index_stats WHERE table_name = 'test_ps_fetch'
ORDER BY index_name, stat_name;
index_name PRIMARY
stat_name n_diff_pfx01
stat_value 0
sample_size 1
stat_description a
index_name PRIMARY
stat_name n_diff_pfx02
stat_value 0
sample_size 1
stat_description a,b
index_name PRIMARY
stat_name n_leaf_pages
stat_value 1
sample_size NULL
stat_description Number of leaf pages in the index
index_name PRIMARY
stat_name size
stat_value 1
sample_size NULL
stat_description Number of pages in the index
index_name idx
stat_name n_diff_pfx01
stat_value 0
sample_size 1
stat_description c
index_name idx
stat_name n_diff_pfx02
stat_value 0
sample_size 1
stat_description c,d
index_name idx
stat_name n_diff_pfx03
stat_value 0
sample_size 1
stat_description c,d,a
index_name idx
stat_name n_diff_pfx04
stat_value 0
sample_size 1
stat_description c,d,a,b
index_name idx
stat_name n_leaf_pages
stat_value 1
sample_size NULL
stat_description Number of leaf pages in the index
index_name idx
stat_name size
stat_value 1
sample_size NULL
stat_description Number of pages in the index
SELECT index_name, seq_in_index, column_name, cardinality
FROM information_schema.statistics WHERE table_name = 'test_ps_fetch'
ORDER BY index_name, seq_in_index;
index_name idx
seq_in_index 1
column_name c
cardinality 0
index_name idx
seq_in_index 2
column_name d
cardinality 0
index_name PRIMARY
seq_in_index 1
column_name a
cardinality 0
index_name PRIMARY
seq_in_index 2
column_name b
cardinality 0
SELECT
table_rows, avg_row_length, max_data_length, index_length
FROM information_schema.tables WHERE table_name = 'test_ps_fetch';
table_rows 0
avg_row_length 0
max_data_length 0
index_length 16384
UPDATE mysql.innodb_table_stats SET
n_rows = 1000,
clustered_index_size = 5
WHERE
table_name = 'test_ps_fetch';
UPDATE mysql.innodb_index_stats SET
stat_value = 20
WHERE
table_name = 'test_ps_fetch' AND
index_name = 'PRIMARY' AND
stat_name = 'n_diff_pfx01';
UPDATE mysql.innodb_index_stats SET
stat_value = 90
WHERE
table_name = 'test_ps_fetch' AND
index_name = 'PRIMARY' AND
stat_name = 'n_diff_pfx02';
UPDATE mysql.innodb_index_stats SET
stat_value = 3
WHERE
table_name = 'test_ps_fetch' AND
index_name = 'idx' AND
stat_name = 'n_diff_pfx01';
UPDATE mysql.innodb_index_stats SET
stat_value = 11
WHERE
table_name = 'test_ps_fetch' AND
index_name = 'idx' AND
stat_name = 'n_diff_pfx02';
FLUSH TABLE test_ps_fetch;
SELECT seq_in_index, column_name, cardinality
FROM information_schema.statistics WHERE table_name = 'test_ps_fetch'
ORDER BY index_name, seq_in_index;
seq_in_index 1
column_name c
cardinality 6
seq_in_index 2
column_name d
cardinality 22
seq_in_index 1
column_name a
cardinality 40
seq_in_index 2
column_name b
cardinality 200
SELECT
table_rows, avg_row_length, max_data_length, index_length
FROM information_schema.tables WHERE table_name = 'test_ps_fetch';
table_rows 1000
avg_row_length 81
max_data_length 0
index_length 16384
DROP TABLE test_ps_fetch;
set @@use_stat_tables = @save_use_stat_tables;
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