Bug #69948 Please ensure that innodb_temp_data_file_path defaults to tmpdir if not set
Submitted: 7 Aug 2013 8:25 Modified: 26 Aug 2013 8:01
Reporter: Simon Mudd (OCA) Email Updates:
Status: Not a Bug Impact on me:
None 
Category:MySQL Server: Options Severity:S3 (Non-critical)
Version:5.7.X OS:Any
Assigned to: CPU Architecture:Any

[7 Aug 2013 8:25] Simon Mudd
Description:
A new variable has been created in 5.7: http://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_temp_data_file...

This must be set explicitly if you want to change it from it's default. Yet there's already a mysql parameter for specifying the default temporary location: tmpdir.

It should not be necessary to have to explicitly configure both settings on 5.7 as that is an extra maintenance/configuration effort.

How to repeat:
Look at the documentation.

Suggested fix:
Make innodb_temp_data_file_path use the value from tmpdir if not defined.

It can still be modified to be different from this default, but reduces extra configuration settings when you start to use 5.7.
[7 Aug 2013 8:32] Simon Mudd
Partly related to: Bug#69123 (location of default directory to use).
[8 Aug 2013 10:18] MySQL Verification Team
Hello Simon,

Thank you for the report.

Thanks,
Umesh
[21 Aug 2013 9:49] Krunal Bauskar
- Defaulting innodb-temp-data-file-path to use tmpdir will restrict use of 
  multiple instances of mysql-server on same machine.

- As pointed in bug-report too it is possible to change the default location
  of temp-tablespace if specific configuration of mysql-server would like to explore it.

- After considering all the feedback comments related to usability + easy of operation we decided to default it to data-directory.
[26 Aug 2013 8:01] Simon Mudd
Groan.

You said:

"- Defaulting innodb-temp-data-file-path to use tmpdir will restrict use of 
  multiple instances of mysql-server on same machine."

Multi-instance setups are not the normal setup of the server, so why use this as an argument for my suggestion being restrictive?  As you suggest if special setups are needed then by all means allow this setting to be different on different instances.

You said: "
- As pointed in bug-report too it is possible to change the default location
  of temp-tablespace if specific configuration of mysql-server would like to explore it.
"

Again: KISS - keep the default configuration as simple as possible. The current configuration does not seem to do that and thus requires a specific configuration setting in MySQL 5.7 and later possibly in many setups.  That is not ideal.