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MySQL: SQLSTATE[HY000]: General error: 3 Error writing file '/tmp/xyz' (Errcode: 28)

If you run MySQL and this error occurs:

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 SQLSTATE[HY000]: General error: 3 Error writing file '/tmp/MYh0VgDS' (Errcode: 28)

then check if your server isn’t using the famous “overflow” filesystem for /tmp, limited to 1 MB space.

The MySQL error message is - as usual - misleading and non-descriptive.

There are many other possible causes for this error code, so this one here might just be a hint.


MySQL creates rows out of nothing

After running a REPAIR TABLE:


MySQL Kundenkonferenz aka Sun Roadshow 2008

Am 21. Oktober 2008 war ich auf der MySQL Kundenkonferenz 2008 in München.

Es ist schon erstaunlich wie man aus einer anscheinend guten Konferenz (Aussage mehrerer Teilnehmer über die vorherige Veranstaltung) eine reine Werbeveranstaltung machen kann. Gleich zu Beginn gab es eine lange Warteschlange im Foyer des Hilton Hotels, die Damen am Empfang waren mit den über 200 Teilnehmern anscheinend etwas überfordert. Kommt halt nicht jeden Tag vor das alle Teilnehmer kurz vor Konferenzbeginn ankommen. Das Frühstück bzw. das Essen überhaupt war gut, aber für jemanden der keinen Kaffee trinkt blieb dann nur Wasser oder ein paar Sorten Tee zum selbst zubereiten übrig.


Performance issues

Last year, tweakers.net did some performance tests with MySQL and PostgreSQL and they found out that MySQL did not scale very well with many concurrent connections.


Double primary key in MySQL

Got a nice MySQL problem: a table, which has the following primary key: id, id.


Community relations

I decided to have a second talk before my main talk and prepared some slides from the community day in Prato, which took place yesterday. The talk was named “Community relations” and got some attention ;-)


Talks for PGDay accepted

Just got two mails, the PGDay.it staff accepted both talks I had submitted. One talk will be about my table_log, the other about migrating web platforms from Mysql to PostgreSQL.


Pitfalls of missing transactions when handling multiple inserts in MySQL

Imagine, you have a table and a colum is defined NOT NULL. You (and I) expect, that NULL arguments will not go into the table, but instead get rejected.


This years april fool

Too pity, this news is only an april fool:


NULL handling in MySQL

Here is an interesting article about the NULL (mis)handling in MySQL: