sql-statement blocks maschine

Hello,

 

we are using PostgreSQL 8.0.3 under SuSE Linux 9.2 and SCO OpenServer 6.0 and have some perfomance problems. We are working with telnet-clients, which controlls our application on the server. The application does the sql-statements

 

If we have sql-statements e.g. SELECT or UPDATE which takes some minutes to be executed, then this statement blocks the whole maschine. This has the affect, that the telnet-clients work very very slowly, e.g. it takes several seconds from one keystroke to the next one. So you can`t work with the application in a reasonable way.

 

These sql-statments are so variable, that we can`t create a index for each combination.

 

How can we solve that problem?

 

Greeting

Michaela