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From:Simon J Mudd Date:March 17 1999 1:12pm
Subject:Re: beeing informed of changes in rows in a table (real-time prices)
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On Wed, 17 Mar 1999, Michael Widenius wrote:

> Note that in most cases with SQL the performance is depending on how
> many new disk blocks you are accessing.
> 
> If you have an timestamp on each row and only do selects based on
> recent timestamps, MySQL will only access the same disk buffers over
> and over again.  Most OS cache this very good and you have to do real
> many queries to get any significant load.

Ok, this may well help me initially.

> In MySQL 3.23 we will extend
> 
> SHOW TABLES
> 
> to include a lot of information about each table !
[snip]
> - Last changed    !

> I assume the above will help you with your problem!

Yes, using this will reduce the potential load on the server, and enable
me to do the real SELECTs once I know there have been changes.

In the meantime I think using a timestamp in the table, and keeping an eye
on the load will give me an idea of how frequently I can request the data.

Thanks for your comments,

Simon

Simon Mudd  ********  All Trading Brokers Europe  *********  Madrid, Spain
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Thread
Re: [spam 03.86/10.00 -pobox] beeing informed of changes in rows in a table (real-time prices)Ed Carp17 Mar
  • Re: beeing informed of changes in rows in a table (real-time prices)Simon J Mudd17 Mar
    • Re: beeing informed of changes in rows in a table (real-time prices)Michael Widenius17 Mar
      • Re: beeing informed of changes in rows in a table (real-time prices)Simon J Mudd17 Mar
Re: beeing informed of changes in rows in a table (real-time prices)Ed Carp17 Mar