Category Archives: Uncategorized

Two New ASH FORCE_MATCHING_SIGNATURE scripts

I just put two new scripts on my OracleDatabaseTuningSQL GitHub repository. These came out of a PeopleSoft Financials performance problem I was working on that involved a lot of similar SQL statements that used constants instead of bind variables, so … Continue reading

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Plan Change Due to Index Partition Names Mismatch

I want to document a bug I ran across in Oracle 11.2.0.3 on HP-UX Itanium and how it caused unexpected plan changes that would bring the database to its knees with many long running queries running the bad plan. I … Continue reading

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MongoDB test server on Oracle Linux

I use Oracle Enterprise Linux on VirtualBox running on my Windows 10 laptop for test servers (virtual machines) of various types of software. I just setup a MongoDB VM yesterday and thought I would document some of the things I … Continue reading

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Real World Index Example

This is a follow up to my previous post with a real world example of how much difference indexes can make on tables that do not have them. I looked at an AWR report of a peak hour on a … Continue reading

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Simple Index Example

There is a lot to be said about when to add indexes on Oracle tables, but I wanted to show a simple example. In this case we have a table with no indexes and a query with two equal conditions … Continue reading

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Fixed Broken Links

I had a couple of new comments on older blog pages and I noticed that some links pointed to things which no longer exist. I fixed a few things that I knew were wrong. Finally, this week I decided to … Continue reading

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SymPy Tutorial Repository

I have been playing with the Python SymPy package and created a repository with my test scripts and notes: https://github.com/bobbydurrett/sympytutorial Might be helpful to someone. I just got started. I had used Maxima before. SymPy and Maxima are both what … Continue reading

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ORA-14767 when day of month > 28 with interval partitioning month interval

Creating a range partitioned table with a date type partitioning column and a month interval must have a starting partition that has a day < 29 or it gets an ORA-14767 error. The error message “Cannot specify this interval with … Continue reading

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Free Machine Learning Class from MIT

I noticed this new class from MIT: https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-036-introduction-to-machine-learning-fall-2020/ It is about machine learning and is free. I think it has some built in exercises with automatic grading but no instructor to interact with. Since ML is such a hot topic … Continue reading

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60,000 sessions in 64 gigabyte VM using shared servers

Just a quick note. I have an application that is generating thousands of inactive sessions and with the default dedicated server configuration we are having to add more and more memory to our virtual host to support the connections. We … Continue reading

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