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From:Steve Staples Date:February 8 2010 3:21pm
Subject:RE: MyISAM no table lock
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Wow... maybe i should have re-evaluated my php script that does all this... 

It is VERY in-efficient, ever look back at your code/script and think...
WHAT WAS I THINKING?  Well, this is one of those occasions... 

Basically, what i was doing, was running though my freeradius radius
accounting table, looking for duplicate IP addresses, from if i didn't get a
stop packet, and then what I would do, is simulate a stop record to denote
that user isn't online anymore....   

The way i was/am doing it, is so ridiculous, i mean... it works, but when
there are multiple inserts and queries going on at the same time, it was
locking the tables, preventing writes, and it was just being dumb.

I am re-writing it now, so it will be much faster :)

Thanks Johan ;)

On a side note, i am currently looking to switch to InnoDB tables now... 

-----Original Message-----
From: vegivamp@stripped [mailto:vegivamp@stripped] On Behalf Of Johan De
Meersman
Sent: February 8, 2010 10:01 AM
To: mysql@stripped
Subject: Re: MyISAM no table lock

On Mon, Feb 8, 2010 at 3:37 PM, Steve Staples <sstaples@stripped> wrote:

> Hi there.
>
> I was reading last week (and of course, i can't find it now) something
> about
> 'nicifying' a query, so taht it doesn't lock the table...
>
> How is this done?   I've read so much stuff lately, that i can't find it
> for
> the life of me, and google is not being my friend :(
>

Maybe Google feels that you haven't been a partiicularly good friend to
them, of late ? :-)

"Nicifying" a query is not something you can write a manual for, alas.

EXPLAIN your queries.

If you need little data, see if you can pad it to the index you use -
that'll prevent additional disk reads.

InnoDB will help your inserts not block.

Avoid full table scans. Avoid outer joins, they cause full table scans.

et cetera ad nauseam.




-- 
Bier met grenadyn
Is als mosterd by den wyn
Sy die't drinkt, is eene kwezel
Hy die't drinkt, is ras een ezel

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Thread
MyISAM no table lockSteve Staples8 Feb
  • Re: MyISAM no table lockJohan De Meersman8 Feb
    • RE: MyISAM no table lockSteve Staples8 Feb