Bug #4743 ALTER TABLE should have option for myisam_sort_buffer_size for repl
Submitted: 25 Jul 2004 3:09 Modified: 25 Jul 2004 3:46
Reporter: Kevin Burton Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server Severity:S4 (Feature request)
Version: OS:
Assigned to: CPU Architecture:Any

[25 Jul 2004 3:09] Kevin Burton
Description:
I'm running a standard MASTER/SLAVE setup where we have a db1 box and db2 box.

Both machines have 4G of memory with plenty free for the key cache, etc.

I want to run an ALTER TABLE command on the master that will be replicated to the slave.

The problemis that I'm doing this on a table thats 4G of data with numerous indexes.

On MySQL 4.0 setting myisam_sort_buffer_size to a larger value will seriously speed up the ALTER TABLE but this isn't replicated to the slave.

The master will complete and now the slave won't have my buffer size increase so it will take FOREVER to run the query.

It seems that a bunch of queries could be extended to have SET var=value syntax.

For example I could have

ALTER SET myisam_sort_buffer_size=400000000 TABLE FOO ...

and then have this replicated to the slave.

Problem solved.

How to repeat:
Just setup a master slave architecture and then do an alter table.

Suggested fix:
Update syntax to support var setting.
[25 Jul 2004 3:46] Arjen Lentz
Added to internal server ideas list.