The best DBA of all time

[KP Lee]

I gave a suggestion to remove functions that produce a constant in the where clause. With an example that cut the query from 13 seconds to 30 milliseconds. The group proceeded to remove every function they could from where clauses. I asked about removing GETUTCDATE in the maintenance apps, since it didn't produce a constant value. "Since it was a daily cleanup job, the few remaining rows will be picked up the next day." That made emminent sense and since the idividual queries would run quicker, it went into production. Most of the jobs did run faster with no problem and all of them ran faster at first. Didn't pay attention to the jobs, as soon as one went over 24 hours, the next daily job didn't submit. The next job was 48 hours out of date and fairly quickly reached a running time of a week. Since the constant value query still made good sense, we analysed the queries, figured out the inefficiencies in the queries, fixed that as well. (In one case, the datetime field used to delete was indexed. Scratched my head, realized what was going on, forced the query to ignore that field for looking up records and increased loop speed 50 times.) Anyway, even good ideas can have bad consequences. The reason it worked OK with the slower query... If it ran for 16 hours, the next run only had 8 hours to fix. With daily and weekend slowdowns it remained stable.

[Dave Kerr]

It was that story that reminded me and made me post!!!

My Blog: www.dwmkerr.com My Charity: Children's Homes Nepal

[Sander Rossel]

That's great! :laugh:

It's an OO world.

public class Naerling : Lazy<Person>{
public void DoWork(){ throw new NotImplementedException(); }
}