[HyperDB] dbDeltas with HyperDB

Andy Skelton skeltoac at gmail.com
Wed Oct 19 17:43:44 UTC 2011

Why does dbDelta bother with SHOW TABLES at all? Why not just loop
over the table names and do DESCRIBE TABLE on each one?

foreach ( $cqueries as $table => $qry ) {
    $tablefields = $wpdb->get_results( "DESCRIBE $table" );
    if ( $tablefields ) {
        // Generate ALTER TABLE statements
    } else {
        // Use CREATE TABLE statement


On Wed, Oct 19, 2011 at 12:23 PM, Chris Morrell <chris at cmorrell.com> wrote:
> Hey everyone,
> I'm having an issue with HyperDB and the dbDelta function.  dbDelta runs the
> following code:
> $tables = $wpdb->get_col('SHOW TABLES;')
> And then loops through the results.  Well, this can be a real issue with
> sharding, where each table can be located on a different database server.
>  It seems to me that the only way to solve this problem would be to patch
> Wordpress core (have dbDelta check each table's existence individually) and
> also patch HyperDB to properly parse the table name from the individual SHOW
> TABLES query.  There's an existing core
> ticket<http://core.trac.wordpress.org/ticket/17998>that begins to
> address a similar issue, but it won't work with HyperDB.
> Right now I'm just trying to figure out how to approach the issue.  It seems
> like it would affect just about any plugin that uses dbDelta to upgrade
> their database tables.  Has anyone else run into this problem?  Any good
> solutions?
> Thanks!
>  <http://cmorrell.com/> *Chris Morrell*  Web: http://cmorrell.com  Twitter:
> @inxilpro <http://twitter.com/inxilpro>
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