database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-01 03:47:19 +03:00
Code Activity

MDEV-7370: Server deadlocks on renaming a table for which persistent statistics exists

Browse Source 
RENAME TABLE code tries to update EITS statistics. It hung, because
it used an index on (db_name,table_name) to find the table, and attempted
to update these values at the same time. The fix is do what SQL UPDATE
statement does when updating index that it's used for scanning:
- First, buffer the rowids of rows to be updated,
- then make the second pass to actually update the rows

Also fixed the call to rename_table_in_stat_tables() in sql_rename.cc
to pass the correct new database (before, it passed old db_name so cross-
database renames were not handled correctly).

Variant #2, with review feedback addressed.
This commit is contained in:
Sergei Petrunia
2015-11-18 21:31:45 +03:00
parent c2ec897745
commit f91798dd1c
5 changed files with 389 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

95
mysql-test/r/stat_tables_innodb.result
View File

@ -448,6 +448,101 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const PRIMARY PRIMARY 4 const 1 Using index
1 SIMPLE t2 ALL NULL NULL NULL NULL 2 Using where
DROP TABLE t1,t2;
#
# MDEV-7370: Server deadlocks on renaming a table for which persistent statistics exists
#
drop database if exists db1;
drop database if exists db1;
create database db1;
create database db2;
use db1;
#
# First, run the original testcase:
#
create table t1 (i int);
insert into t1 values (10),(20);
analyze table t1 persistent for all;
Table Op Msg_type Msg_text
db1.t1 analyze status Engine-independent statistics collected
db1.t1 analyze status OK
rename table t1 to db2.t1;
# Verify that stats in the old database are gone:
select * from mysql.column_stats where db_name='db1' and table_name='t1';
db_name table_name column_name min_value max_value nulls_ratio avg_length avg_frequency hist_size hist_type histogram
select * from mysql.table_stats where db_name='db1' and table_name='t1';
db_name table_name cardinality
# Verify that stats are present in the new database:
select * from mysql.column_stats where db_name='db2' and table_name='t1';
db_name table_name column_name min_value max_value nulls_ratio avg_length avg_frequency hist_size hist_type histogram
db2 t1 i 10 20 0.0000 4.0000 1.0000 0 NULL NULL
select * from mysql.table_stats where db_name='db2' and table_name='t1';
db_name table_name cardinality
db2 t1 2
#
# Now, try with more than one column and with indexes:
#
use test;
create table t1(a int primary key);
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
use db1;
create table t2 (a int, b int, c int, key IDX1(a), key IDX2(a,b));
insert into t2 select a/10, a/2, a from test.t1;
analyze table t2 persistent for all;
Table Op Msg_type Msg_text
db1.t2 analyze status Engine-independent statistics collected
db1.t2 analyze status OK
alter table t2 rename db2.t2;
# Verify that stats in the old database are gone:
select * from mysql.table_stats where db_name='db1' and table_name='t2';
db_name table_name cardinality
select * from mysql.column_stats where db_name='db1' and table_name='t2';
db_name table_name column_name min_value max_value nulls_ratio avg_length avg_frequency hist_size hist_type histogram
select * from mysql.index_stats where db_name='db1' and table_name='t2';
db_name table_name index_name prefix_arity avg_frequency
# Verify that stats are present in the new database:
select * from mysql.table_stats where db_name='db2' and table_name='t2';
db_name table_name cardinality
db2 t2 10
select * from mysql.column_stats where db_name='db2' and table_name='t2';
db_name table_name column_name min_value max_value nulls_ratio avg_length avg_frequency hist_size hist_type histogram
db2 t2 a 0 1 0.0000 4.0000 5.0000 0 NULL NULL
db2 t2 b 0 5 0.0000 4.0000 1.6667 0 NULL NULL
db2 t2 c 0 9 0.0000 4.0000 1.0000 0 NULL NULL
select * from mysql.index_stats where db_name='db2' and table_name='t2';
db_name table_name index_name prefix_arity avg_frequency
db2 t2 IDX1 1 5.0000
db2 t2 IDX2 1 5.0000
db2 t2 IDX2 2 1.6667
use db2;
#
# Now, rename within the same database and verify:
#
rename table t2 to t3;
# No stats under old name:
select * from mysql.table_stats where db_name='db2' and table_name='t2';
db_name table_name cardinality
select * from mysql.column_stats where db_name='db2' and table_name='t2';
db_name table_name column_name min_value max_value nulls_ratio avg_length avg_frequency hist_size hist_type histogram
select * from mysql.index_stats where db_name='db2' and table_name='t2';
db_name table_name index_name prefix_arity avg_frequency
# Stats under the new name:
select * from mysql.table_stats where db_name='db2' and table_name='t3';
db_name table_name cardinality
db2 t3 10
select * from mysql.column_stats where db_name='db2' and table_name='t3';
db_name table_name column_name min_value max_value nulls_ratio avg_length avg_frequency hist_size hist_type histogram
db2 t3 a 0 1 0.0000 4.0000 5.0000 0 NULL NULL
db2 t3 b 0 5 0.0000 4.0000 1.6667 0 NULL NULL
db2 t3 c 0 9 0.0000 4.0000 1.0000 0 NULL NULL
select * from mysql.index_stats where db_name='db2' and table_name='t3';
db_name table_name index_name prefix_arity avg_frequency
db2 t3 IDX1 1 5.0000
db2 t3 IDX2 1 5.0000
db2 t3 IDX2 2 1.6667
use test;
drop database db1;
drop database db2;
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;