The apr_dbd interface, as shipped with apr-util in RHEL5, explicitly excludes the mysql and postgres drivers. The mysql and pgsql drivers need to be provided in apr-util, or alternative apr-util packages need to be provided with the complete functionality. (This issue has been fixed in apr-util v1.3 by splitting out all dbd, ldap, and crypto(1.4) code into optional loadable modules in their own RPM packages).
The pgsql driver is included in the RHEL5 package - it is linked into libaprutil rather than built as a DSO, support for which postdates RHEL5 GA. The mysql driver is proposed to be added in 5.4, via bug 252073, but that's a private bug so I'll leave this one open for tracking purposes.
This request was evaluated by Red Hat Product Management for inclusion, but this component is not scheduled to be updated in the current Red Hat Enterprise Linux release. If you would like this request to be reviewed for the next minor release, ask your support representative to set the next rhel-x.y flag to "?".
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHEA-2010-0310.html