Oracle

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Video : Online Conversion of a Non-Partitioned Table to a Partitioned Table in Oracle 12.2 Onward

Today’s video demonstrates the online conversion of a non-partitioned table to a partitioned table. This functionality was introduced in Oracle 12.2.

The examples in the video are taken from this article.

Franck Pachot's picture

“Segment Maintenance Online Compress” feature usage

By Franck Pachot

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On Twitter, Ludovico Caldara mentioned the #licensing #pitfall when using the Online Partition Move with Basic Compression. Those two features are available in Enterprise Edition without additional option, but when used together (moving online a compressed partition) they enable the usage of Advance Compression Option:

Franck Pachot's picture

Find the SQL Plan Baseline for a plan operation

By Franck Pachot

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If you decide to capture SQL Plan Baselines, you achieve plan stability by being conservative: if the optimizer comes with a new execution plan, it is loaded into the SQL Plan Management base, but not accepted. One day, you may add an index to improve some queries. Then you should check if there is any SQL Plan Baseline for queries with the same access predicate. Because the optimizer will probably find this index attractive, and add the new plan in the SPM base, but it will not be used unless you evolve it to accept it. Or you may remove the SQL Plan Baseline for these queries now that you know you provided a very efficient access path.

But how do you find all SQL Plan Baselines that are concerned? Here is an example.

I start with the SCOTT schema where I capture the SQL Plan Baselines for the following queries:

fritshoogland's picture

What’s new with Oracle database 11.2.0.4.200114 versus 11.2.0.4.200414

This blogpost takes a look at the technical differences between Oracle database 11.2.0.4 PSU 200114 (january 2020) and 200414 (april 2020). This gives technical specialists an idea of the differences, and gives them the ability to assess if the PSU impacts anything.

Functions

oraclebase's picture

VirtualBox 6.1.6

Along with all the other Oracle quarterly patches comes VirtualBox 6.1.6.

The downloads and changelog are in the usual places.

I’ve done the installation on Windows 10, macOS Catalina, and Oracle Linux 7 hosts. All worked fine.

I’ve done some Vagrant builds with it and they worked too.

oraclebase's picture

Video : Invisible Columns in Oracle 12.1 Onward

In today’s video we demonstrate the invisible columns feature introduced in Oracle 12.1.

The video is run through of the examples in this article.

oraclebase's picture

Video : Online Table Move Operations in Oracle 12.2 Onward

In today’s video we demonstrate how to move, or rebuild, a table as an online operation.

This video was done as a response to some questions about the previous video on shrink operations. As usual, the video is based on some stuff I’ve written previously.

fritshoogland's picture

Oracle library cache cursor child generation

This post is about library cache SQL cursors, and how these are managed by the database instance.

fritshoogland's picture

Oracle multi-tenant and library cache isolation

This post is the result of a question that I got after presenting a session about Oracle database mutexes organised by ITOUG, as a response to the conference cancellations because of COVID-19. Thank Gianni Ceresa for asking me!

The library cache provides shared cursors and execution plans. Because they are shared, sessions can take advantage of the work of previous sessions of creating these. However, by having these shared, access needs to be regulated not to have sessions overwrite each other’s work. This is done by mutexes.

The question I got was (this is a paraphrased from my memory): ‘when using pluggable databases, could a session in one pluggable database influence performance of a session in another pluggable database’?

oraclebase's picture

The Oracle ACE Program : My 14 Year Anniversary

I was checking my calendar, thinking I was about to jack it in for the day, and I noticed it’s April 1st, which means it’s my 14th year anniversary of being an Oracle ACE. Can’t believe I nearly missed that!

As usual I’ll mention some of the other anniversaries that will happen throughout this year.

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