Column And Table Redefinition With Minimal Locking

TLDR: Note to future self… (1) Read this before you modify a table on a live PostgreSQL database. If you do it wrong then your app might totally hang. There is a right way to do it which avoids that. (2) Especially remember the lock_timeout step. Many blog posts around the ‘net are missing this and it’s very important.

Yesterday I was talking to some PostgreSQL users (who, BTW, were doing rather large-scale cool stuff (more...)

PASS Summit, Day 2 Keynote!

After a long night in a coma to restore my energy expel for the first day of Summit, (anyone else exhausted already???)  I showed up bright eyed and bushy tailed for the second day’s keynote and the blogger table.  

Me this week…


The awesome Wendy Pastrick started us out letting us know what goes on behind the scenes deciding how PASS makes decisions…and then broke into song.  She will survive…. (more...)

Where / Having

There’s a very old mantra about the use of the “having” clause that tells us that if it’s valid (i.e. will always give the same results) then any predicate that could be moved from the having clause to the where clause should be moved. In recent versions of Oracle the optimizer will do this for itself in some cases but (for reasons that I’m not going to mention) I came across a silly example (more...)

Goldengate ERROR OGG-02037 Failed to retrieve the name of a missing Oracle redo log.

One extract got abended and wasn't able to start in Oracle Goldengate Version 23194417_FBO. The redologs were present but extract was still abended and threw following error in the report file.


ERROR OGG-02037 Failed to retrieve the name of a missing Oracle redo log.


The solution for this error is to unregister, register and then start the extract as follows:

GGSCI (test) 6> unregister extract ext database 2018-11-07 17:07:03 (more...)

Pass Summit 2018 Keynote 11/7

So I made it to PASS Summit 2018.  After a flight from an airport with one gate-  yes, you heard me right, one gate.  No Wi-Fi, no connectivity and four employees at the airport.  It was a new level of disconnect.

After a number of parties last night, I’m at the bloggers table for the first keynote this morning.  The first keynote started with an energized talk from PASS president and (more...)

creating local repository yum install linux

Follow the below procedure

[root@ebs-app-xx-xx u01]# yum repolist

[root@ebs-app-xx-xx u01]# yum list installed | grep createrepo

createrepo.noarch                         0.9.9-28.el7             @anaconda/7.5

[root@ebs-app-xx-xx u01]# createrepo /u01/Packages/


[root@ebs-app-xx-xx u01]# cd /etc/yum.repos.d

[root@ebs-app-xx-xx yum.repos.d]# ls -tlr

total 4

-rw-r–r–. 1 root root 358 Nov  4 22:55 redhat.repo

Now, create custom repository

[root@ebs-app-xx-xx yum.repos.d]# cat custom.repo


name=Custom Repository





you can check how (more...)

Add ORDER BY to make ANY query faster

Yes it’s SCBT day here in Perth!

SCBT = Silly Click Bait Title Smile

This post is just a cautionary tale that it is easy to get caught up judging SQL performance solely on a few metrics rather than taking a more common sense approach of assessing performance based on the true requirements of the relevant component of the application.  I say “true requirements” because it may vary depending on what is important to the (more...)

Oracle 19c – Features We Know About

Oracle Open World was interesting like every year. This year, Oracle started talking about features that will probably be in Oracle 19c (which is the last 12.2 release). The rumor says that it will be out in the first half of 2019 (somewhere around April-May). As you might know, I didn’t attend a lot of … Continue reading "Oracle 19c – Features We Know About"

To or To Not Specify Thread# When Creating SRL?

Just quick and dirty notes on some references.

Notice that the Thread # is 0 for the SRL’s. Resist the temptation to explicitly assign the SRL to a specific thread. If you are using Oracle RAC, a SRL with with Thread # of 0 can be used by any primary instance, any thread from the primary.

Warning: standby redo logs not configured for thread <n> on <db_unique_name> (Doc ID 1956103.1)
Bug (more...)

Birmingham City University (BCU) Talk #7

Yesterday I went to Birmingham City University (BCU) to do a talk on “Graduate Employability” to a bunch of second year undergraduate IT students. I’ve done this a few times at BCU, and also at UKOUG for a session directed at students.

The session is what originally inspired the my series of blog posts called What Employers Want.

I’ve mentioned before, these sessions are a little different to your typical conference sessions. Perhaps you should (more...)

Arbeitsgruppen Treffen „Engineered Systems“ in Nürnberg

Wie jedes Jahr trifft sich die Arbeitsgruppe „Engineered Systems“

am Vorabend der Konferenz.

Termin: Montag, den 19.11.2018, um 17:00 Uhr

Ort: Nürnberg, ConventionCenter Ost Messezentrum, 90471 Nürnberg

Der Raum befindet sich im Zwischengeschoss

Wir haben spannende Themen auf der Tagesordnung und das Oracle Exadata und ODA Product-Management ist ebenfalls vor Ort.

Es wird wie immer interessant mit vielen Neuigkeiten rund um die Engineered Systems

Das Networking kommt natürlich auch nicht zu kurz

Wir sehen (more...)

Interval versus Range partitions

One of the nice things about partitioning in the database is that partition pruning can quickly eliminate the requirement to read large amounts of data when the partitioning key(s) are appropriately provided in your queries (and DML). This also extends to queries where the values provided do not map to any partitions.

Here’s a simple example of a range partitioned table which only cover the values from (less than) 1 to a ceiling of 6.

Oracle 18c and 12c on Fedora 29

Danger, Will Robinson! Obligatory warning below.

So here we go…

Fedora 29 has been out for a bit over a week now. Over the weekend I had a play with it and noticed a couple of differences between Fedora 28 and Fedora 29 as far as Oracle installations are concerned. There are some extra packages that need to be installed. Also, one of the two symbolic (more...)

FIRST_ROWS_10 CBO Is Hopeless, It’s Using The Wrong Index !! (Weeping Wall)

There’s an organisation I had been dealing with on and off  obeer the years who were having all sorts of issues with their Siebel System and who were totally convinced their performance issues were due directly to being forced to use the FIRST_ROWS_10 optimizer. I’ve attempted on a number of occasions to explain that their […]

UKOUG Tech 18

One month to go before the big event in Liverpool. so I’ve been browsing the agenda to get some idea of the talks I’ll probably go to. At present this is what my list looksl like:


14:00	Database block checking - the unknown truth
15:00	TBD
16:10	Oracle Database 12c consolidation: why and how to manage CPU resources
17:10	Securefiles - the hidden storage organisation inside LOB segments


 9:00	The Optimizer & the  (more...)

PASS Summit 2018- Times up!

I’ve had my nose to the grindstone for almost four months now investing my brain in new technology, reinvesting fully in performing technical work and prioritizing it all to ensure that I’ll be successful.  I stepped back from many speaking events to make sure my private and professional life would succeed in this transition, but that doesn’t mean I would skip PASS Summit.  What I didn’t expect was the event would arrive so quickly and (more...)

MobaXTerm 11.0

Looks like MobaXTerm 11.0 was released yesterday

The downloads and changelog are in the usual places.

This version comes with a log list of bug fixes and improvements in the changelog.



MobaXTerm 11.0 was first posted on November 2, 2018 at 6:27 pm.
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Why Automation Matters : Keep Your Auditors Happy

We were having some of our systems audited recently. I’ve been part of this sort of things a few times over the years, but I was pleasantly surprised by a number of the questions that were being asked during this most recent session. I’ll paraphrasing some of their questions and my answers.

  • How do you document your build processes? We have silent build scripts (where possible). The same build scripts are used for each build, (more...)

The Openworld Mega-Download!

If you are sad and pathetic enthusiastic and interested in content like me, once a large conference like OpenWorld is over, I like to have the content (slides etc ) from not just the sessions I attended, but all of the sessions I could not attend. In fact, I typically would like to have any and all available content, because that is probably the next best thing to attending the conference.

In particular, now that (more...)

Open World 2019 Dates

In the past, during OOW Oracle published the official dates of OOW of the following year, but in the last few years they stopped doing this, so we can’t be sure when OOW19 will be. There was a lot of unknown about OOW18 until the official dates were released (and 2018 is the first year … Continue reading "Open World 2019 Dates"