Author Archives: Bobby

So,  I play one computer game – Nethack.  I have a page on the blog if you want some information about it.  I just finished building a 32 bit Linux virtual machine running on VMware player for the purpose of … Continue reading →

I wasn’t sure if people would find a post on a bug that interesting.  If you don’t have the same bug I’m not sure what you would get out of it.  But, it is what I’m working on. Here are … Continue reading →

I’m on call this week so I didn’t plan to do any blog posting but I had an interesting performance issue this morning that I thought would be helpful to document.  This is somewhat redundant to earlier posts but maybe … Continue reading →

Another simple script: zip. This is like an AWR report where you see a difference in v$ view values over time.  But, it is for  one wait event over a single interval.  Simple but possibly useful. drop table waitdiff; create … Continue reading →

I’ve taken a script I use to show a particular wait event over time and parameterized it a bit to make it more general. Here is a zip of the script: zip(updated). This is the same sort of information you … Continue reading →

I modified the example from my previous post to see if on Exadata I could denormalize two tables and get the same performance without an index on the denormalized table that I get with the index on the normalized ones. … Continue reading →

I was working on the example from an earlier blog post that showed how the optimizer could not correctly estimate the number of rows accessed on a table if the non-join condition was on a different table.  Number of rows … Continue reading →

I have a table with interval partitioning and subpartitions and I want to extract the DDL including all the system generated partitions and subpartitions which get created as new rows with dates beyond the last partition’s high value get inserted. … Continue reading →

Just found out that all the good documentation for the DBMS_METADATA package is in the Utilities manual.  I’ve just been looking at the “PL/SQL Packages and Types Reference” manual for the details of how to use DBMS_METADATA.  I’ve been handcuffing … Continue reading →

I thought I would do a fun “day in the life” blog post about the work I’m doing today.  And then chaos ensues! 8:22 AM MST  After starting this blog post and reading my email I updated my time card … Continue reading →