WOW: Tips and Tricks
.: WOW Operations Performance
Q: "I'm having performance issues selecting, grouping and sorting from logicals over multiple physical files?"
A: Typically, performance is nearly all outside of WOW’s control. What happens is:
1) WOW passes an SQL statement to the AS/400.
2) The AS/400 executes the statement using the best known optimization as determined by the OS/400. This includes such factors as file size, and database indexes.
3) After execution, WOW reads the data returned from OS/400, generates HTML, and sends to the browser. Nearly all performance is dependent on the AS/400.
To Check Relative Performance:
Take the SQL statement from WOW and use AS/400’s STRSQL and run the same statement and compare results or put the SQL into Client Access or operations navigator and run it to compare results. The results from each method can then be compared. Typically, the WOW results for non-cached data will be slightly slower because WOW is reading all the data and then generating HTML for a browser.