Category Archives: Uncategorized

Table Statistics With Histograms procedure – TSWH

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

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Testing maximum number of Oracle sessions supported by shared servers

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

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Lessons from RMAN restore and recovery

I was on call last week and had to recover a production database to a particular point in time to recover some data that was lost.  I had to leave the production database intact but use a development server to … Continue reading

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Renaming files for RMAN restore

Here is a script I hacked together Tuesday night to figure out how to fit all my production data files and temp files on a development server for a RMAN restore of a production backup onto a new server: DECLARE … Continue reading

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Craig Shallahamer

I’ve been thinking about how to use my blog to describe different individuals who have helped me learn about Oracle performance tuning.  I was thinking about having a single blog entry or page describing several people but have decided that … Continue reading

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Comparing Characters and Numbers in Oracle

In Oracle when you compare a character and a number in a SQL WHERE clause Oracle converts the character value to a number rather than the other way around.  I built a simple example to help me understand how this … Continue reading

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Yet Another Bind Variable Type Mismatch (YABVTM)

Hopefully this isn’t too redundant.  Saw another performance issue today caused by a type mismatch between a bind variable and the column it was compared to in a SQL statement.  I saw this in some real code and then built … Continue reading

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How to figure out disk network latency using cached blocks

I was working on some disk performance problems and came across a simple way to test the latency or delay built into the networks that connect my database servers to their disk storage.  All I have to do is read … Continue reading

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Subscribing to Oak Table blogs feed

I’ve seen some very good information posted in this feed which combines blog postings from many different Oracle performance experts who are part of what is called the “Oak Table” http://www.oaktable.net/feed/blog-rss.xml (NO LONGER EXISTS) I’ve been using Internet Explorer to … Continue reading

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inode lock contention

In my forum discussion about free buffer waits I came across a term that I didn’t understand: “inode lock contention”.  I’m pretty sure I had seen this same term years ago on one of Steve Adams’ pages on IO.  But, … Continue reading

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