[drupal-devel] MySQL 3, MySQL 4 and MySQL 5

[Dries Buytaert]

On 01 May 2005, at 18:55, Gerhard Killesreiter wrote:
> Generally, it will cause the same problem for me as switching to PHP 
> 4.3
> did. I run Debian and Debian stable does only provide MySQL 3. I 
> haven't
> checked if there is a .deb for MySQL 4 on backports.org yet.
>
> However, since our database abstraction layer is very modular, I could
> even continue to use mysql 3 if I wrote an appropriate include file and
> would be willing to live without some of the more advanced features.
>
> The question is if we should ship a database.mysql3.inc file with
> Drupal 4.7 or not.

Well, the syntax for row-level locking is this:

  SELECT * FROM cache WHERE cid = %s FOR UPDATE
  UPDATE cache SET ... WHERE ...

A "SELECT ... FOR UPDATE" reads the data and sets exclusive locks on 
each row it reads.  AFAIK, this is valid ANSI SQL, yet it might give 
errors on either MySQL 3 or PostgreSQL.  I don't have a MySQL 3 
installation to test with these days but clearly, this is not something 
that is easily fixed using the database layer (unless you want to 
rewrite queries of course).

--
Dries Buytaert  ::  http://www.buytaert.net/