Author Archives: Bobby

About Bobby

I live in Chandler, Arizona with my wife and three daughters. I work for US Foods, the second largest food distribution company in the United States. I have worked in the Information Technology field since 1989. I have a passion for Oracle database performance tuning because I enjoy challenging technical problems that require an understanding of computer science. I enjoy communicating with people about my work.

DBMS_UTILITY.FORMAT_CALL_STACK Change in 12.2 and later

Quick note. During my 11.2.0.4 to 19c upgrade that I have been writing about we found a difference in behavior of DBMS_UTILITY.FORMAT_CALL_STACK. I tested it on several versions, and it switched in 12.2. Now it puts the procedure name within … Continue reading

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Python 3.8.1 Linux Install Without Root

I wanted to install the latest Python on Linux in a low powered user’s home directory and not have the install interfere with the Python that comes with Linux. I wanted my own local copy of Python that I could … Continue reading

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AZORA with Viscosity lunch and learn Thursday 2/13/20

Quick note. The next AZORA meetup will be next Thursday, 2/13/2020. Be sure to RSVP on Viscosity’s web site: https://tips.viscosityna.com/modernize2020-phoenix/ (DOES NOT EXIST) I don’t know about you but we are busy moving to or implementing on 19c so these … Continue reading

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Query Plan Change Diagnosis Example

This week I investigated an issue with a query that was suddenly a lot slower in one test environment than another. It runs about 2 seconds in the good case as well as in production. But it was now running … Continue reading

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Datapump Import Partitioned Tables ORA-00600 qesmaGetPamR-NullCtx

I have not yet had time to build a test case and prove this out, but I wanted to document one last bug that we found so far in our 11.2.0.4 to 19c upgrade. We tried copying a bunch of … Continue reading

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db_securefile PREFERRED results in ORA-60019 with small uniform extents

Last 19c upgrade issue. Working on our new 19c database, several things died off with errors like this: Our tablespaces had small uniform extents and our 19c database had defaulted the parameter db_securefile to PREFERRED. We bumped our uniform extent … Continue reading

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Datapump Import Fails on Tables With Extended Statistics

Quick post before I leave on vacation. We used Datapump to import a schema from an 11.2 HP-UX database to a 19c Linux database and got errors on a few tables like these: Workaround was to create the table first … Continue reading

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Merge Always Updates Sequence Number

This is nothing new, but I wanted to throw out a quick post to document it. If you have a sequence.nextval in the insert part of a merge statement the merge calls nextval for all the updated rows as well. … Continue reading

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Database Link to 9.2 Database from 19c

I have mentioned in previous posts that I am working on migrating a large 11.2 database on HP Unix to 19c on Linux. I ran across a database link to an older 9.2 database in the current 11.2 database. That … Continue reading

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So Far So Good with Force Logging

I mentioned in my previous two posts that I had tried to figure out if it would be safe to turn on force logging on a production database that does a bunch of batch processing on the weekend: post1, post2. … Continue reading

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