This tip is a follow-up to both of the tips I published last week. Like Bypassing a Locked Record, Take Two, it has to do with locked records. Like Be Specific When Updating With SQL Cursors, it deals with SQL updates.

You may remember that there are two ways to update in SQL. The positioned update uses a cursor to update one row at a time, as we talked about last week. Updating through a cursor is similar to updating with native I/O.

The searched update, the easier and more powerful of the two, does not work through

Does anyone have any knowledge or references related to the difference in performance between doing a put to a journaled data queue vs. doing an open and a put (no connect) to an MQSeries queue?

–James

In MQSeries, opens are expensive, so if you keep the queue open and do multiple puts, you will get very good performance. Using a data queue, you will get better performance as long as there are not too many entries in the data queue. If the data queue overflows (no telling where this might occur, but I have seen it around 100 messages), then

Last week, I discussed the best ways to automatically monitor iSeries, System i, and Power i systems for hidden signs of trouble, and I focused on monitoring the QSYSMSG and QSYSOPR message queues for developing problems. This week, I’m changing direction to discuss several specific i5/OS monitoring situations that can also help you detect system problems as they occur.

Trouble-Finding Tools

As I mentioned last week, the following are the best places to look for trouble in your OS/400, i5/OS, and i operating systems:

• The QSYSMSG message queue
• The System Operator (QSYSOPR) message queue
• Disk drive statistics
• Active job