How to Checksum Downloads

As a DBA, in your time, you will need to download files such as Oracle binaries, patches, etc.  As a rule of thumb, you should always checksum you downloads, to ensure they are free of corruption.  In my example, I needed to download:

This is the Quarterly Full Stack Download Patch for Exadata, which is 10 zip files that (more...)

Choosing a password scheme for the database

In the Security Guide there is a section to assist you with the decisions about what rules you might want to have in place when users choose passwords, namely attributes like the minimum length of a password, the types of characters it must (and must not) contain, re-use of old passwords etc etc. The documentation refers to a number of pre-supplied routines that are now available in 12c to assist administrators.  This is just (more...)

How to obtain the Historical Database Total Used and Allocated Size from OEM Repository

From time to time, it’s useful to know the total allocated size of a database at OS level, how much of it has been used and what the maximum total size the database can grow to at OS level, see blog post:
How to obtain the Database Total Used, Allocated and Max Size

However, it’s also goo to know the historical size.  The below query will give you this from the Oracle Enterprise Manager (OEM) repository:


SQL Server 2012 and Changes to the Backup Operator Permissions

I’m off to Columbus, Ohio tomorrow for a full day of sessions on Friday for the Ohio Oracle User Group.  The wonderful Mary E. Brown and her group has set up a great venue and a fantastic schedule.  Next week, I’m off to SQL Saturday Vancouver to present on DevOps for the DBA to a lovely group of SQL Server attendees.  It’s my first time to Vancouver, (more...)

How to obtain the Database Current, Total and Max Size

From time to time, it’s useful to know the total current size of a database at OS level, how much of it has been used and what the maximum total size the database can grow to at OS level.

The below query will give you this:

SELECT round(sum(used_ts_size)/1024/1024, 2) total_used_db_size_tb,
 round(sum(curr_ts_size)/1024/1024, 2) total_current_db_size_tb,
 round(sum(max_ts_size)/1024/1024, 2) total_max_allocated_db_size_tb
(SELECT df.tablespace_name, (df.bytes - sum(fs.bytes)) / (1024 * 1024) used_ts_size,
df.bytes / (1024 *  (more...)

Managing the WINDOW_ID in Goldengate V11.

When we import data into the landing schema on a Dat Warehouse via Goldengate, we add 3 fields to each record detailing when and how the record got loaded. This can be found in the *.inc files under $GG_HOME/dirinc on the target GG installation. An example of this is:

AskTOM–more experts to help you!

I’m thrilled to announce the “formal” addition of globalization and characterset guru Sergiusz Wolicki to the AskTOM team. I say “formal” addition because the team was already getting guidance from Sergiusz whenever we had tough question on charactersets, but just like his enthusiasm to help customers on the forums, Sergiusz was keen to help our AskTOM visitors as well.

Sergiusz is a 20+ year veteran of Oracle Corporation, with over half that time specializing in (more...)

Oracle Code … Not for database people ?

Jump over to the Oracle Code home page and you will see the “mission statement” of the Oracle Code conference series:

“Learn from technical experts in sessions for developing software in Java, Node.js, and other languages and frameworks.”

You might hence be thinking that “old school” stuff like (relational) database technology has no place at such a conference, and certainly the agenda looks slanted away from database technologies.  But I think you’re (more...)

Words I Don’t Use, Part 5: “Wait”

The fifth “word I do not use” is the Oracle technical term wait.

The Oracle Wait Interface

In 1991, Oracle Corporation released some of the most important software instrumentation of all time: the wait statistics that were implemented in Oracle 7.0. Here’s part of the story, in Juan Loaiza’s words, as told in Nørgaard et. al (2004), Oracle Insights: Tales of the Oak Table.
This stuff was developed because we were running a benchmark (more...)

Storage Server: datasets, snapshots and performance

Storage Server: datasets, snapshots and performance This is a long post, but with lots of pictures. Kind of a management overview ;) Datasets and snapshots Datasets As may have become clear from a previous post, I have one volume, with a (a -to date- single) dataset (ds1). This was not the result of experience, of deep thought, it was just copied from Benjamin Bryan who did an entry on ZFS

Chart Your Course With sar

The sar (system activity reporter) is a Linux utility that actually started life long ago in System V Unix.

In spite of its ancient origins, sar is still quite useful, and has even been enhanced in recent versions of Linux.

The use of sar is not limited to root – any user can run sar and its utilities.  Most Linux systems have sar installed and enabled by default to collect sar data at 10 (more...)

A Different Cause for enq: TM – contention

Doc ID 1905174.1 on My Oracle Support looks at how to resolve this wait event.
It says:
If contention is occurring, then the most common reason is missing Foreign Key (FK) index on the FK constraint columns in the Child tables.
In my experience until very recently, this has always been true. However, I have now found another possible cause, which I have recreated below in an Oracle 11.2.0. (more...)

Oracle New Version Numbering

Oracle is using the same numbering scheme since I’ve started working with it (7.2). The 5 number scheme with the release number, patchset and PSU is quite confusing and the post I wrote about that (here) is still very popular. But now, Oracle is changing that. They’ve decided to come up with a new and … Continue reading Oracle New Version Numbering

Join Elimination Bug

A few years ago a bug relating to join elimination showed up in a comment to a post I’d done about the need to keep on testing and learining. The bug was visible in version and, with a script to replay it, I’d found that it had disappeared by

Today I had a reason to rediscover the script, and decided to test it against 12.2.0. (more...)

Amazon Web Services (AWS) : That’s Customer Service!

If you were reading my Twitter stream about 11 days ago you will have seen me tweet the following message.

That feeling when your reserved instance ran out and you didn’t realise. 🙁

The story was I logged into AWS and noticed the reserved instance for my website had expired about a month and a half before. For those that don’t know, buying reserved instances reduces your compute costs because you are committing to (more...)

Goodbye Oracle (Modern Love)

  It’s with a mixture of excitement, trepidation and a touch of sorrow that I today handed in my resignation after 6 years at Oracle Corporation. My plans at this stage are to take a bit of time-off initially, before going back to providing Oracle Database consulting and training services as I’ve done in the […]

Database Smart Flash Cache on which OS (OL5, OL6, OL7)?

I got a DM from someone a couple of days ago asking me to try the Database Smart Flash Cache (DSFC) feature on a few combinations of DB version and OS version.

You are probably thinking, why bother? Both Oracle 12.1 and Oracle 12.2 are supported on a variety of Oracle Linux versions, so it works on all of them right? Wrong…

  • Oracle 12.1 : DSFC works on OL5 and OL6, but (more...)

Friday Philosophy – Are Leaving Presentations A Quaint British Tradition?

A few days ago a friend, Robert Lockard, started a discussion on Facebook about bad bosses and the strange things they did. I mentioned how one of my first bosses had refused to do my leaving presentation, arguing with his boss (very loudly so all could hear, despite it being in “an office” – a plastic box in the corner) that he did not want to be nice to me and do the presentation. (more...)

KBHS-00600: Internal Error, Arguments [1] [kbhshtCreateDataBucket] Error During Backup To Oracle Cloud

When setting up Oracle Cloud Backup Service for first time and the Oracle Database Cloud Backup Module has been installed successfully using:
Installing the Oracle Database Cloud Backup Module

Your RMAN session will hang and eventually give the following error:

Starting backup at 2017/08/10 12:56:58 
current log archived 
RMAN-00571: =========================================================== 
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== 
RMAN-00571: =========================================================== 
RMAN-03002: failure of backup plus archivelog command at 08/10/2017 16:20:05 
ORA-19554: error allocating device, device type: SBT_TAPE,  (more...)

Latest Delphix Blog Post and Upcoming Webinars

In my latest blog post on the Delphix site, I continue my conversation with why DevOps is the next step for DBAs and how DBAs can embrace this next step in their evolution.

This is an extensive series of blog posts, (four so far) to be followed by an ebook, a podcast and two webinars.  One is to be announced soon from Oracle called, “The DBA Diaries” and (more...)