How to do performance tuning ?

[prathip]

We are runnig a online transaction processing application on informix 4gl. The application has become very slow now after using it for about six month. Can you help me how we can improve the performance ?

 

[olded]

Hi:

Let's start with the basics; Have you performed update statistics on the database?

Regards,

Ed

 

[prathip]

Hi,
Sorry to come back late.
No. I don’t know much about Informix. I referred the web and found some command like “onstat” for (Informix dynamic server) but these commands I can not find in our system. Is there a different between Informix 4GL and dynamic server?

Thank you in advance
prathip.

 

[olded]

Hi:

Yes, there's a big difference. Informix Dynamic Servier, IDS, is the database while, Informix 4GL is the application language that speaks to the database. onstat is an informix utility for monitoring the database.

The UPDATE STATISTICS command recalculates the data in the system tables, and, generally, speeds up queries. It's common to run UPDATE STATISTICS, US, daily, especially, if you have a database with a lot of transactions.

US is valid 4GL syntax, so a program like this works:


main

DATABASE testdb
update statistics

end main

However, most of the time, US is executed manually using the query language from Informix's dbaccess or isql utilities. For automatiing this process, check out the software archive for the Internation Informix User's group,

http://www.iiug.org.

I recommend reading the Update Statistics docs. If your database is very large, running US with no options may take a long time. For example, you can run it against single tables in the database and even single columns.

Regards,


Ed

 

[prathip]

Hi Ed,

Do we need to have IDS and 4GL if we want to run the 4GL application?
The onstat command in not in the server. Is that mean the IDS is not installed ?

Many thnks.
prathip

 

[olded]

Prathip:

Your 4GL application is communicating with a database. It doesn't have to be IDS; It could be version 5 or even standard engine, SE.

You can't find onstat. If it's version 5, all the database utilities start with "tb".

Also, is your 4GL application on the same server as the database? It doesn't have to be. In that case, you won't find any of the database related commands on the 4GL server.

Is shell variable INFORMIXSERVER set? If you are running IDS, it'll be set to the unix server where your database resides.

change to $INFORMIXDIR/bin directory. What commands do you see here?

Regards,

Ed