Re: LOCK TABLES on compressed tables...

[Paul Cadach]

Hi,

----- Original Message -----
From: "Michael Widenius" <monty@stripped>
To: "Paul Cadach" <paul@stripped>
Cc: <internals@stripped>
Sent: Friday, September 07, 2001 4:20 AM
Subject: Re: LOCK TABLES on compressed tables...


>
> Hi!
>
> >>>>> "Paul" == Paul Cadach <paul@stripped> writes:
>
> <cut>
>
> Paul> I needs to perform some sequential queries (select and updates) and
I must
> Paul> sure that noone writes to tables at this time. For single queries
I'm never
> Paul> uses locks...
>
> In this case you should lock tables that you only read from with a
> READ lock and other with a WRITE lock.
>
> Having a READ lock on a table will ensure that no one thread will
> write to it.

For my situation I don't want to block reads, but make sure other thread is
waiting until lock will be released. For this, I uses WRITE lock which
blocks other threads until lock exists but also blocks reads from locked
table(s) :((( I.e. its looks like to have READ lock with WAIT option which
blocks other threads when they tries to make READ WAIT lock until other READ
WAIT lock exists. Threads which not uses locks must works transparently.


WBR,
Paul.