Author Archives: Bobby

I got a Kindle for Christmas.  I thought I would enter the 21st century and try reading books on a Kindle, though I kind of like the feel of a real book.  One use I had in mind when I … Continue reading →

I have a large sub-partitioned table on our Exadata system that I need to backup prior to a change.  In the past we have done backups of this large table to another table using inserts and parallel DML,  but it … Continue reading →

This is simple, but fun.  I have studied the regular expression features in Oracle but haven’t really used them.  I needed a list of all the tables in a particular schema that started with a certain string and ended with … Continue reading →

I’ve done a little research to figure out what a “soft parse” is because I’m working on a system that is experiencing performance issues doing soft parses.  My own translation is that a “soft parse” occurs whenever the Oracle optimizer … Continue reading →

The SHARED_CONTEXT_SENSITIVE VPD policy type seems like a good option for VPD predicates that don’t need to change during a user’s session. I’m working on a system with VPD policies in place to cause users to see only certain parts … Continue reading →

I’ve been working for hours on a performance issue the past week and this one and found a strange situation:  A new function based index sped up the queries that used it, but slowed down other queries that didn’t use … Continue reading →

I thought that an invisible index was never queried, but that it was only maintained as the table was modified.  But, when you use the dbms_stats package to gather statistics on a table, including its indexes, the invisible indexes are … Continue reading →

We ran into a performance issue where all of the top queries in our AWR report were doing a LIKE comparison of a NUMBER column against a character literal like this: customer_number LIKE ‘123456%’ customer_number is a selective predicate and … Continue reading →

I’m still doing state dumps as described in my previous post. I wanted to collect the state dumps (diag process trace files) from all nodes of my Exadata database and decided to write a couple of scripts to automate it … Continue reading →

One of my favorite children’s books when my children were younger was one about the Berenstain Bears where Father Bear tries to teach his son how to ride a bike and keeps making all these dumb mistakes.  “Let that be … Continue reading →