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To: "'Ard Biesheuvel'" <a.k.biesheuvel@ewi.tudelft.nl>,
	<internals@lists.php.net>
Date: Sat, 22 May 2004 16:50:52 +0100
Organization: The Brain Room Ltd.
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Subject: RE: pdo design
From: wez@thebrainroom.com ("Wez Furlong")
References: <40AF7400.7040909@ewi.tudelft.nl>

Hey Ard,

When you say database, do you mean separate database connection, or separate
named databases on the same connection?

PDO::beginTransaction() initiates a transaction for a given connection ($dbh)
in a more or less portable way. You're not always guaranteed to be able to do
that; extending it for multiple database handles seems a bit optimistic :)

Could you expand on what Firebird does here?  Are there other DB's that
support this too?

--Wez.

> -----Original Message-----
> From: Ard Biesheuvel [mailto:a.k.biesheuvel@ewi.tudelft.nl] 
> Sent: 22 May 2004 16:39
> To: internals@lists.php.net
> Cc: helly@php.net; ilia@prohost.org; wez@thebrainroom.net; 
> george@omniti.com
> Subject: pdo design
> 
> Guys,
> 
> I saw the alpha of PDO on pecl. I was wondering if we could 
> discuss the 
> design of it a bit more before putting too much work into it.
> 
> In particular, the way transactions are represented is not very 
> practical. Generally, databases that support transactions 
> will support 
> multiple concurrent transactions against the same database. Firebird 
> also supports transactions against multiple databases. [which 
> does *not* 
> mean you can join tables from different DBs, it just means ACID over 
> multiple DBs]
> 
> This means that in some cases you must specify both the 
> connection and 
> the transaction when generating a statement. [I'm not sure if others 
> RDBMSs support this, but it might be something we will see 
> more in the 
> future.]
> 
> In short:
> 
> In addition to $db->startTransaction(), maybe we could add
> PDO::startTransaction($db1 [,$db2 [,$db3]]).
> 
> In addition to $db->prepare(), maybe we could add a Transaction 
> interface whose instances would allow being called as
> 
> $trans->prepare($query)
> 
> and maybe even
> 
> $trans->prepare($db, $query)
> 
> 
> Your thoughts please ?
> 
> -- 
> Ard
> 
> 
>