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MDEV-16757 Memory leak after adding manually min/max statistical data

for blob column

ANALYZE TABLE <table> does not collect statistical data on min/max values
for BLOB columns of <table>. However these values can be added into
mysql.column_stats manually by executing proper statements.
Unfortunately this led to a memory leak because the memory allocated
for these values was never freed.
This patch provides the server with a function to free memory allocated
for min/max statistical values of BLOB types.
This commit is contained in:
Igor Babaev
2018-07-13 17:48:30 -07:00
parent ad9d1e8c3f
commit c89bb15c31
6 changed files with 116 additions and 0 deletions

View File

@ -551,5 +551,33 @@ SELECT CONVERT_TZ( '1991-09-20 10:11:02', '+00:00', 'GMT' );
CONVERT_TZ( '1991-09-20 10:11:02', '+00:00', 'GMT' )
NULL
set use_stat_tables=@save_use_stat_tables;
#
# MDEV-16757: manual addition of min/max statistics for BLOB
#
SET use_stat_tables= PREFERABLY;
CREATE TABLE t1 (pk INT PRIMARY KEY, t TEXT);
INSERT INTO t1 VALUES (1,'foo'),(2,'bar');
ANALYZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 analyze status Engine-independent statistics collected
test.t1 analyze status OK
SELECT * FROM mysql.column_stats;
db_name table_name column_name min_value max_value nulls_ratio avg_length avg_frequency hist_size hist_type histogram
test t1 pk 1 2 0.0000 4.0000 1.0000 0 NULL NULL
test t1 t NULL NULL 0.0000 3.0000 NULL NULL NULL NULL
DELETE FROM mysql.column_stats
WHERE db_name='test' AND table_name='t1' AND column_name='t';
INSERT INTO mysql.column_stats VALUES
('test','t1','t','bar','foo', 0.0, 3.0, 1.0, 0, NULL, NULL);
SELECT * FROM mysql.column_stats;
db_name table_name column_name min_value max_value nulls_ratio avg_length avg_frequency hist_size hist_type histogram
test t1 pk 1 2 0.0000 4.0000 1.0000 0 NULL NULL
test t1 t bar foo 0.0000 3.0000 1.0000 0 NULL NULL
SELECT pk FROM t1;
pk
1
2
DROP TABLE t1;
set use_stat_tables=@save_use_stat_tables;
set optimizer_switch=@save_optimizer_switch_for_stat_tables_test;
SET SESSION STORAGE_ENGINE=DEFAULT;