Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?

[Baron Schwartz]

Hi,

On Thu, Jun 24, 2010 at 3:37 AM, Konstantin Osipov <kostja@stripped> wrote:
> * Baron Schwartz <baron@stripped> [10/06/24 11:35]:
>> > - To allow easy file system level backups of the databases
>> > - To prepare a database for a snapshot
>> > - (Optional) Flush things to disk, so that a restart is faster.
>> I have seen many people use it as a general-purpose write barrier.
>> For example, in Alex Davies's new High Availability Cookbook, he
>> suggests using it before SET GLOBAL read_only = 1, to be sure the
>> change has really taken effect for all connections when performing a
>> failover.
>
> Starting from 5.0, a useless suggestion.
> SET GLOBAL read_only is implemented by means of FTWRL.

Yes.  My point in citing this specific example was to not be like
those people on Wikipedia who write "many people say..." as a way to
sound credible ;-)