Hi Ingo,
Thanks again. I'll probably file a bug report after what you said. But I'm still not sure if the problem happens inside MySQL or outside (OS). And as it happens only on big tables (speaking of well above a gigabyte) it's not something you can easily test many times to generate a test case, as every run will take about an hour... and it possibly happens only under full load on the production server. ;-)
Do you have an answer to my question on myisam_max_sort_file_size?
> The manual says on myisam_max_sort_file_size: "Don't use the fast sort index
> method to create an index if the temporary file would become larger than this."
> What's meant by temporary file? MYI or MYI+MYD?
It could save me from some additional tests and thus from some hours of work (and would allow me to concentrate on the real cause more quickly).
Best regards,
Beat
Beat Vontobel
http://www.futhark.ch/mysql