NOCACHE sequences come at a cost

by | May 27, 2018 | Uncategorized

Every so often I will look at an AWR report for a slow system, and updates to the data dictionary table SEQ$ will show up as a top resource consumer.  This is usually because sequences are defined using NOCACHE.  In this post we show why this matters and how to avoid...

Oracle undo, blocks read, and performance

by | May 13, 2018 | Uncategorized

Today we talk about the purpose of Oracle undo and give a demonstration of its use and little bit of what Oracle is doing under the covers.  We also show how query performance can be affected by what else is going on in the database. In the last post on transactions,...