Ignores WHERE

Anon

Okay, I have a script that runs in cron every five minutes. The script queries the database and acts on the results. This script has been running non-stop since last June.

Today when the script ran at 9am, the database (MySQL) appeared to ignore the WHERE clause and returned all the rows. At 8:55 it ran without any problems. At 9:05 it ran without any problems. But this is the second time it has happened since last June.

Is this a bug in MySQL? I mean, it's obviously rare - the script has been executed around 83,000 times and the database has only ignored the WHERE twice. But I can't see why on Earth this is happening.

--Mike

[deleted]

MySQL is flakey, but I never had it ignore the where clause on me.

What's in the where clause? any vars from outside that could f*ck things up?

Anon

The WHERE is just "WHERE Sent = 1". That is all. There are no external vars, the WHERE is hard coded.

--Mike

[deleted]

And ofcourse there's no way to verify wether Sent was not really 1 for all records at that point in time (ie: some other script f*cked up)?

Anon

We looked through the binary log - there were no updates to the data in that table within an hour (either way) of the problem

[deleted]

Then it's probably a clitch in mysql. I could get very nasty and say 'mysql sucks' (which it does ofcourse) but that would be cheap.

Maybe you should send this in as a bugreport and see what mysql themselves think of it.

Anon

Hey vincent, hasn't someone else posted this exact same problem like a year ago? I seem to remember seeing this go by a while back.

Thank the gods I don't use mysql.

Anon

That was probably me posting about it last time it happened! :-)

I think I will see what MySQL think about it. I may seriously consider migrating the production servers to PostgreSQL. It's just replication issues that bother me - I make heavy use of MySQL's circular replication feature on our production servers.

--Mike

Anon

Well, I just pg_dumpall my database every night for backup, but I've NEVER had my mainline production postgresql server go down, EVER during the two years I've been using it.

I do keep a <1 week old live server ready to take over should anything ever go wrong, but it just sits there, testing new versions of postgresql and ugly SQL that might clog the arteries of the production box, but never gets "taken to the prom" so to speak.

In the replication versus stability environment, I'm reminded of my argument against lifetime warranties on tools, like those from Craftsman and Ace Hardware. I buy most of my tools from companies like Thorson, who make rock solid tools that never seem to break. Lifetime warranty? I don't know. But if you're in the middle of death valley, trying to get your car running, and you break your last 14mm wrench, how much good does it do ya to be able to get a new one WHEN YOU GET BACK TO CIVILIZATION? You need a tool that works now, in the desert, not that will be replaced for free after some wanderer takes it off your dessicated carcass while hiking death valley at night...
Same thing goes for replication. It's a nice security blanket, but it can't make up for an unreliable database.