Author Archives: Bobby

One of our senior developers found a way to greatly improve the performance of a query by adding a dynamic sampling hint for a table that had multiple correlated conditions in its where clause.  This led me to try to … Continue reading →

So, this isn’t really Oracle related except that I got a new Windows 7 laptop to support Oracle and I’m getting an annoying popup message every time I try to run putty to access a database server. I looked up … Continue reading →

So, I had to get a new work laptop to install Oracle 12c.  I was on Windows XP and even though I knew my company would have paid for me to get a new one a long time ago I … Continue reading →

We are running the Oracle delivered automatic optimizer stats job on some of our 11.2 Oracle databases and the job is not completing for some of our tables.  But, the list of these tables is buried in a trace file … Continue reading →

In two previous posts I’ve discussed the possibility of switching from the default dedicated server configuration to shared servers to support a large web farm. The original post I decribed how Tom Kyte recommended a Youtube video that champions reducing … Continue reading →

I wanted to download the new version of the Oracle database software to test it out but I have an old laptop running Windows XP, a 32-bit OS.  So far Oracle hasn’t released a 32-bit Windows or Linux version on … Continue reading →

Sunday night we worked with Oracle Support on a performance issue with a query that had been running for over 14 hours even though it ran the previous weekend in five minutes.  Oracle Support showed us how to use coe_xfr_sql_profile.sql … Continue reading →

We have been discussing query tuning at work and I’ve come back to an example of the Oracle optimizer choosing the wrong plan due to an error in its calculation of the number of rows returned by a query.  I … Continue reading →

I’ve uploaded the most recent version of a stored procedure that I use for gathering optimizer statistics on a table in Oracle.  You can download a zip here.  See the file buildandtest.bat to see how to build the needed tables … Continue reading →

I’ve been testing a shared servers configuration and I was asked to push a test database to its limits to see how many sessions it would support.  It was really just a test of how many could login, not how … Continue reading →