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,
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