Addressing a DB Bytes Read performance alert (PEGA0004)
This presentation is part of the Designing and Building for Performance Self-Study Course.
The DB Bytes Read (PEGA0004) alert (aka the "byte governor") is triggered whenever an interaction with PRPC causes more than 50mb of data, which is a large amount of data for a single request, to be read from the PegaRULES database. Typically, these happen when working with lists of data via ListView, SummaryView, and Obj-List rules.
When this alert is generated, it is essential to locate the rules that cause this much data to be read and limit them by adding more criteria, capping the rows returned, and/or reducing the number of data columns returned. This alert is often triggered when a rule requires reading of the BLOB or pzPvStream, which can also be quite large.
- Since the 50mb threshold is high, consider asking the PRPC administrator to reduce (alert) this threshold to 20mb or less.
- You can terminate the PRPC task when this threshold is encountered. It is highly recommended that this is enabled to prevent runaway, unbounded queries from consuming all available memory and crashing the system.