Bug #68849 Wrong changelog entry about mysqldump and events in 5.5.30?
Submitted: 3 Apr 2013 8:52 Modified: 10 Apr 2013 19:22
Reporter: Hartmut Holzgraefe Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Documentation Severity:S3 (Non-critical)
Version:mysql-5.5.30 OS:Any
Assigned to: Paul Dubois CPU Architecture:Any

[3 Apr 2013 8:52] Hartmut Holzgraefe
Description:
The 5.5.30 changelog says 
 
  For dumps of the mysql database, mysqldump skipped the event table
  unless the --events option was given. To skip this table if that is 
  desired, use the --ignore-table option instead (Bug #55587, Bug #11762933)

What actually seems to have happened though is that mysqldump from 5.5.30 behaves exactly like the 5.5.29 version when it comes to dumping events, with the only difference being an extra warning on stderr:

  -- Warning: Skipping the data of table mysql.event. Specify the --events option explicitly.

The result of "mysqldump mysql" with an actual EVENT existing in mysql.event only differs by the version string at the beginning and the timestamp at the end though, both versions produce a dump that contains the CREATE TABLE statement for the events table but no INSERT statements for the existing event data.

How to repeat:
Run "mysqldump mysql" against a server that has at least one EVENT created, e.g.

  USE test; 
  CREATE EVENT myevent ON SCHEDULE AT CURRENT_TIMESTAMP + INTERVAL 1 HOUR DO FLUSH TABLES;

Create dumps with the mysqldump binary from 5.5.30 and with a binary from a previous version:

  mysql-5.5.30/bin/mysqldump mysql > dump.30
  mysql-5.5.29/bin/mysqldump mysql > dump.29

Compare the dump files:

  diff -u dump.29 dump.30

and see that they only differ by version string and timestamp
[10 Apr 2013 19:22] Paul Dubois
Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly, and will be included in the next release of the relevant products.

Updated the changelog entries. There were two different patches for this bug.

For 5.1.68, 5.5.30:

For dumps of the mysql database, mysqldump skips the event table
unless the --events option is given. mysqldump now prints a warning
if invoked without --events that the mysql.event table is not dumped
without that option.

For 5.6.9, 5.7.0:

For dumps of the mysql database, mysqldump skipped the event table
unless the --events option was given. This no longer occurs. To skip
the event table if that is desired, use the --ignore-table option
instead