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From:Baron Schwartz Date:June 24 2010 7:18am
Subject:Re: Should FLUSH TABLES WITH READ LOCK wait for updating
transactions?
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Monty,

> To answer this one, we should consider what FLUSH TABLES is used for.
>
> It's main (only?) purposes are
>
> - 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.
Thread
Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Konstantin Osipov21 Jun
  • re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Michael Widenius22 Jun
    • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Konstantin Osipov23 Jun
      • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Michael Widenius24 Jun
    • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Baron Schwartz24 Jun
      • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Konstantin Osipov24 Jun
        • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Baron Schwartz24 Jun
        • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Rob Wultsch24 Jun
          • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Konstantin Osipov24 Jun
            • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?Rob Wultsch24 Jun
  • Re: Should FLUSH TABLES WITH READ LOCK wait for updating transactions?MARK CALLAGHAN23 Jun