Posts by Marc Fielding

Disabling Triggers in Oracle

Yes you can still disable triggers per-session in Oracle, but you have to have a GoldenGate license, set the enable_goldengate_replication parameter, use a program name that starts with replicat, and set your module to OGG.

Oracle RAC on the Cloud, Part 3

This is part 3 of a multipart series of getting oracle RAC running on a cloud environment. In part 1, we set up a NFS server for shared storage. In part 2, we set up OS components for each RAC server. Now we finish up the OS configuration and move to Oracle grid infrastructure.

Oracle RAC on the Cloud, Part 2

In part 1 of this series, we talked about some of the challenges of setting up Oracle RAC on a public cloud provider, and went on to order some VMs from provider Gandi, and finally configuring a NFS server for shared storage. In this post, we move on to configuring the rac servers themselves, rac01 and rac02.

Oracle RAC on the Cloud, Part 1

I’ve been working on moving a lot of the testing and R&D work I do away from local virtual machines and onto cloud environments, for a few reasons: I can avoid carrying around a laptop all the time, and rather log onto the cloud wherever I happen to be It’s easy to scale down and…

Sleuthing for Temporary Space Spendthrifts

I was recently looking at an issue where a large database server was running out of temp space. The issue had happened in the past, so the goal was to identify what had been causing the system to run out of temp. Although ORA-1555 messages will appear in the database alert log (with query text) when a query runs out of temporary space, they only talk about the query that was “unlucky” enough to be attempting to get space when the tablespace was full, not who was using the temp space.

Revealing the Hints Behind the Automatic SQL Tuning Advisor

A client recently supplied a list of 50+ SQL IDs that should receive SQL profiles, and I’ve been working with Gwen Shapira to review the list. Further discussion showed that this list had come from the Automatic SQL Tuning feature, installed by default in Oracle 11g. The report includes a list of recommended SQL profiles ordered by “Maximum Benefit”, and in our case it included several hundred statements. The expected workflow, as far as I can gather, is to see the recommendations, look at the before- and after- execution plans, and accept the recommendations. Before blindly accepting recommendations, though, I like to see what exact changes are being proposed. They aren’t listed anywhere in the report, and require some extra work to uncover. The first step is to get the automatic SQL tuning advisor report. (

Temporary Tablespaces: to BIGFILE or Not to BIGFILE

The environment was an Exadata environment undergoing pre-production stress testing. We used Real Application Testing to take a highly-concurrent OLTP workload, and replayed the workload with the synchronization parameter set to FALSE, effectively increasing concurrency beyond the original test system. AWR showed a large volume of buffer busy activity.

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