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2 posts tagged with "sql"

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MediaWiki 1.13.0

· One min read

I just upgraded Winiki to MediaWiki 1.13.0. But once I had done so, the site failed with following error message:

SQL failed ... column "rev_parent_id" does not exist.

Now, it turns out that the revision table was added to MediaWiki in version 1.10.0, so it seems this was something broken since the upgrade to 1.10.0 back in November last year, but was only now being exposed. No doubt the issue has arisen because I insist on using PostgreSQL.

DB2 Net Search Extender with optional CONTAINS search parameters

· 8 min read
IBM DB2

I have a number of DB2 stored procedures that must use the NSE CONTAINS scalar function with optional search parameters. It turns out, that if you write such stored procedures in the most obvious way, then the performance is terrible. However, with a little insight, and some resulting tweaks, such stored procedures can be sped up immensely - eg more than 1,000 times!!

But first, let me explain what I mean by "optional search parameters". Basically, what I mean is stored procedures that return a result set based on a number of potential filter parameters, where the an NSE search string is just one of many possible filters.