20 simultaneous cartesian products on large tables would be expected to make
any sql server busy, not to mention use a lot of temporary disk space.
Are you sure you are not running out of disk space?
Andrea Carpani wrote:
>Here's my problem:
>I've just installed mysql version 3.23.51 (before this one I tried
>3.23.49) compiled from scratch with:
>CFLAGS="-fomit-frame-pointer -O3 -fPIC" ./configure --prefix=/opt/mysql
> --disable-shared --with-mysqld-user=mysql --with-debug
>It compiles and runs fine, but fails as soon as I use a script to load
>it up a bit.
>The script itself just opens a database connection, than does a
>"select * FROM $table1 s,$table2 t"
>where the two tables are choosen randomly (some of the tables are quite
>big), then repeats this with another (not cached) connection. The script
>runs on another machine. If I leave the script running it hangs mysql db
>in , say, 20 minutes. If I launch simultaneously 20 such scripts 3
>minutes are enough.
>By "mysql hangs" I mean that there's no way to connect to get a
>"processlist" or a "debug", and the scripts remain blocked.
>If I stop the scripts and I wait some time (2 minutes) everything seems
>to come back to normality.
>Is there anyone who uses mysql on HP-UX under heavy load that can give
>me a hint?