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Message Posted: Thu, 04 Sep 2003 @ 22:47:05 GMT

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Hi Bob,

Could you expand on your comments. I do a lot of work in this area so I'm very interested in hearing about possible problems or limitations with DBQL.

I've worked with several customers in the past 18 months where we have captured the vast majority of the SQL that we felt was important for analysis using AccessLog (V2R4). In some cases, we logged all SQL. In other cases, we logged all SQL except for things like; high volume OLTP queries that were very predictable and controlled, predictable batch processes like TPUMP, MLOAD, etc. The SQL captured has been extremely valuable for analysis, even with the limitations of AccessLog, such as; the limit to the length of SQL captured, no logging of Dynamic SQL executed from Stored Procedures, no logging of queries that only access a volatile temp table, etc.

I know that SBC has a huge system and huge volumes, so perhaps your experiences are different than most. The largest client I have worked with had a 40 node system that logged about 65,000 queries every business day, on average, using AccessLog. Over the past twelve months, there were 51 days when over 100,000 queries were logged in a day, peaking at 287,000. This did not excluded some of the production batch IDs because we felt that the queries were predictable and well understood so logging seemed unnecessary, at least for the types of analysis that we were trying to do. We also did not log queries from a high query volume reporting application because the application generated its own query log table, which was updated at time of query execution.

Although I have not yet worked on a production V2R5 system with DBQL, I'm anticipating that DBQL will be more robust and more valuable (based on limited demo system use, documentation and Partners presentations) than AccessLog. Since you have some experience with DBQL, it would be great if you could share your experiences and what problems or limitations you might be seeing that would be valuable for the list to know.

Thanks,

Thomas F. Stanek
TFS Consulting, Inc.

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