| Bug #85787 | Inconsistent INFORMATION_SCHEMA across restarts after RENAME | ||
|---|---|---|---|
| Submitted: | 4 Apr 2017 14:53 | Modified: | 4 Apr 2017 17:39 |
| Reporter: | Luca Pino | Email Updates: | |
| Status: | Verified | Impact on me: | |
| Category: | MySQL Server: Information schema | Severity: | S3 (Non-critical) |
| Version: | 5.6 and 5.7 | OS: | MacOS |
| Assigned to: | CPU Architecture: | Any | |
| Tags: | foreign constraints, foreign keys, information_schema, osx, restart | ||
[4 Apr 2017 14:54]
Luca Pino
This is the script to then go and reproduce the issue
Attachment: restart_mysql_bug.sql (application/octet-stream, text), 554 bytes.
[4 Apr 2017 17:39]
MySQL Verification Team
Thank you for the bug report.
miguel:~ miguel$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.17 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> CREATE SCHEMA `MY_DB_1` DEFAULT CHARACTER SET utf8 ;
Query OK, 1 row affected (0.03 sec)
mysql> CREATE SCHEMA `MY_DB_2` DEFAULT CHARACTER SET utf8 ;
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> CREATE TABLE `MY_DB_1`.`MY_TABLE_1` (
-> `id` INT NOT NULL,
-> PRIMARY KEY (`id`));
Query OK, 0 rows affected (0.13 sec)
mysql>
mysql> CREATE TABLE `MY_DB_1`.`MY_TABLE_2` (
-> `foreignKeyColumn` INT NULL,
-> INDEX `foreign_KEY_1_idx` (`foreignKeyColumn` ASC),
-> CONSTRAINT `foreign_KEY_1`
-> FOREIGN KEY (`foreignKeyColumn`)
-> REFERENCES `MY_DB_1`.`MY_TABLE_1` (`id`));
Query OK, 0 rows affected (0.31 sec)
mysql>
mysql> RENAME TABLE `MY_DB_1`.`MY_TABLE_1` TO `MY_DB_2`.`MY_TABLE_1`;
Query OK, 0 rows affected (0.00 sec)
mysql> RENAME TABLE `MY_DB_1`.`MY_TABLE_2` TO `MY_DB_2`.`MY_TABLE_2`;
Query OK, 0 rows affected (0.01 sec)
mysql> SELECT * FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE where REFERENCED_TABLE_SCHEMA <> CONSTRAINT_SCHEMA\G
Empty set (0.37 sec)
mysql> exit
Bye
miguel:~ miguel$ sudo launchctl unload -F /Library/LaunchDaemons/com.oracle.oss.mysql.mysqld.plist
miguel:~ miguel$ sudo launchctl load -F /Library/LaunchDaemons/com.oracle.oss.mysql.mysqld.plist
miguel:~ miguel$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.17 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> SELECT * FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE where REFERENCED_TABLE_SCHEMA <> CONSTRAINT_SCHEMA\G
*************************** 1. row ***************************
CONSTRAINT_CATALOG: def
CONSTRAINT_SCHEMA: MY_DB_2
CONSTRAINT_NAME: foreign_KEY_1
TABLE_CATALOG: def
TABLE_SCHEMA: MY_DB_2
TABLE_NAME: MY_TABLE_2
COLUMN_NAME: foreignKeyColumn
ORDINAL_POSITION: 1
POSITION_IN_UNIQUE_CONSTRAINT: 1
REFERENCED_TABLE_SCHEMA: MY_DB_1
REFERENCED_TABLE_NAME: MY_TABLE_1
REFERENCED_COLUMN_NAME: id
1 row in set (0.15 sec)
mysql>
Description: When doing a RENAME of two tables with a foreign constraint across them to a different DB on OSX, the foreign constraint works out just fine as long as you don't restart the server. In particular the query: SELECT * FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE where REFERENCED_TABLE_SCHEMA <> CONSTRAINT_SCHEMA; does not return any result before restarting the server. As soon as you restart the server the same query returns a result. I've reproduced this on 5.6 and 5.7 on OSX. It does not seem to apply to other platforms (cannot reproduce it on MySQL over Docker) How to repeat: Run: ------ CREATE SCHEMA `MY_DB_1` DEFAULT CHARACTER SET utf8 ; CREATE SCHEMA `MY_DB_2` DEFAULT CHARACTER SET utf8 ; CREATE TABLE `MY_DB_1`.`MY_TABLE_1` ( `id` INT NOT NULL, PRIMARY KEY (`id`)); CREATE TABLE `MY_DB_1`.`MY_TABLE_2` ( `foreignKeyColumn` INT NULL, INDEX `foreign_KEY_1_idx` (`foreignKeyColumn` ASC), CONSTRAINT `foreign_KEY_1` FOREIGN KEY (`foreignKeyColumn`) REFERENCES `MY_DB_1`.`MY_TABLE_1` (`id`)); RENAME TABLE `MY_DB_1`.`MY_TABLE_1` TO `MY_DB_2`.`MY_TABLE_1`; RENAME TABLE `MY_DB_1`.`MY_TABLE_2` TO `MY_DB_2`.`MY_TABLE_2`; ------ Check the results of: ------ SELECT * FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE where REFERENCED_TABLE_SCHEMA <> CONSTRAINT_SCHEMA; ------ Restart the server Now check again the results of: ------ SELECT * FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE where REFERENCED_TABLE_SCHEMA <> CONSTRAINT_SCHEMA; Suggested fix: INFORMATION_SCHEMA should return the same info before and after a restart.