Re: [Slashcode-development] MySQL observations

[Eric D. <eri...@ja...>]

Well, you might want to check
http://www.mysql.com/doc/L/O/LOCK_TABLES.html

for lock tables

Stephen Clouse wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> While doing the Oracle conversion I noticed a few rather quirky things in the
> MySQL code that didn't make much sense to me.  I just wanted to run these by
> someone more knowledgable, to see if I was correct in porting/emulating/removing
> them.
>
> 1.  LOCK TABLES.  This is called in a number of places, but I don't understand
>     why.  Because MySQL lacks row-level locking?  To ensure a consistent
>     read/write due to the lack of transactions?  Some explanation is necessary
>     so I can determine what's best for Oracle to do in those spots.  For the
>     time being I substituted LOCK TABLE IN EXCLUSIVE MODE, but this is not the
>     most (read: least) efficient thing to do in Oracle.
>
> 2.  1=1.  This pops up in several where clauses.  It looks like a noop to me,
>     but something mentioned it was some sort of optimization.  MySQL specific,
>     perhaps?  Oracle just ignores it, from what SQL traces have told me.
>
> The other thing I'm wondering is, where is Slash's "main" loop?  AutoCommit is a
> pretty major loss on Oracle, so it would be desirable to turn it off and perform
> a single commit after each client request, both for performance and to avoid
> partial writes.  I'm looking into doing this but can't determine where it should
> be done at.
>
> If anyone knows the answers, please clue me in.
>
> - --
> Stephen Clouse <the...@wa...>
> warpcore.org Founder, Chief Megalomaniac, and Evil Overlord
>
> -----BEGIN PGP SIGNATURE-----
> Version: PGP 6.5.8
>
> iQA/AwUBOuT9Td1EXk7JbKbMEQLPWgCcDkMVtkzMnGh5SU6T/tPtpeCT72AAnRcf
> EdvSiBS8aUJmAIDXLbxuqxn5
> =Uubj
> -----END PGP SIGNATURE-----
>
> _______________________________________________
> Slashcode-development mailing list
> Sla...@li...
> http://lists.sourceforge.net/lists/listinfo/slashcode-development

--
Back up my hard disk? I can't find the reverse switch!

Eric Dannewitz - Adventurer, saxophonist, good-timer (crook? quite possibly),
clarinetist, manic self-publicist, part-time flautist(flutist?), macintosher, and
often thought to be completely out to lunch. http://www.jazz-sax.com