Bug #29405 SHOW CREATE TABLE needs a DATA lock, instead of METADATA

• Submitted: 27 Jun 2007 23:57
• Modified: 6 Aug 2007 9:12
• Reporter: Marc ALFF
• Status: Won't fix
• Category: MySQL Server: Locking
• Severity: S3 (Non-critical)
• Version: 5.0/5.1
• OS: Any
• CPU Architecture: Any

[27 Jun 2007 23:57] Marc ALFF

Description:
SHOW CREATE TABLE require the user to provide a DATA lock,
when using SHOW CREATE TABLE within a LOCK TABLES / UNLOCK TABLES section.

This is wrong, as SHOW CREATE TABLE does not need the table data,
but only the table metadata.

How to repeat:
use test;

drop table if exists t1;
drop table if exists t2;

create table t1 (a int);
create table t2 (b int);

lock table t1 read;

# Fails with
# query 'show create table t2' failed: 1100:
# Table 't2' was not locked with LOCK TABLES

# This should pass :
show create table t2;
unlock tables;

drop table t1;
drop table t2;

Suggested fix:
N/A

[28 Jun 2007 0:21] MySQL Verification Team

Thank you for the bug report.

[28 Jun 2007 15:01] Sergei Golubchik

Well, it shows auto_increment value, which is not metadata

[6 Aug 2007 9:12] Konstantin Osipov

As Serg suggests, auto_increment value is currently stored in the storage engine.