RAC 12.2, part 2

Well, today was an interesting day. My ASM, configured with so much effort, stopped working:

root@rac1 grid]# . ~grid/.bashrc
[root@rac1 grid]# crsctl start ohasd
CRS-4640: Oracle High Availability Services is already active
CRS-4000: Command Start failed, or completed with errors.
[root@rac1 grid]# crsctl start cluster
CRS-2672: Attempting to start 'ora.crf' on 'rac1'
CRS-2672: Attempting to start 'ora.storage' on 'rac1'
CRS-2676: Start of 'ora.crf' on 'rac1' succeeded
ORA-27140: attach to post/wait facility failed

Adding flexibility to your PostgreSQL clusters – Using EDB Failover Manager

Using PostgreSQL in enterprise environments gets more and more popular. And why not? This extremely stable and performant database can compete with ease with almost all enterprise database installations out there today.

Competing technically? Sure!
Competing from a business perspective? Absolutely!!

Making sure your database systems stay up during planned maintenance? Absolutely yes, no discussion about that!
Ensuring your systems stay up during a catastrophic failure of your master? Yes! We need to ensure 99. (more...)

RAC 12.2

I am in the process of installing RAC 12.2. The installation procedure has undergone a significant change, for the better. It’s now much easier to install it. However, memory and disk requirements have skyrocketed. I needed to allocate 10GB of memory for each of my nodes, 12 GB for OCR and 64GB for the management database. My computer will be barely large enough to run both Commserve and those two nodes together:


I am (more...)

12.2 New Feature: the FLEX ASM disk group part 3

In the previous 2 parts of this mini series I introduced the Flex ASM disk group and two related concepts, the Quota Group and File Group. In what should have become the final part (but isn’t) I am interested in checking whether quotas are enforced.

(Un)fortunately I have uncovered a few more things that are worth investigating and blogging about, which is why a) this isn’t the last post and b) it got a bit (more...)

Optimistic ORA_ROWSCN 2: the SCN

In my previous post, I covered lost updates. Before saying how ORA_ROWSCN can help avoid them, I need to talk about the SCN. It's hard to be simple and correct about such a fundamental element of the Oracle database, but I'll try.

Set-based processing

Last week I participated in Oracle’s Real World Performance event — four days of lectures, quizzes, live demos and hands-on exercises. It was quite interesting, even more so than I expected it to be.

Understandably, a lot of time was spent discussing the perils of row-by-row processing. After all, it was Real World Performance, so it was based on performance problems that the authors of the course faced most often. And many, if not most, (more...)

Optimistic ORA_ROWSCN 1: Lost Updates

I've gotten lots of feedback about my proposal to use ORA_ROWSCN for optimistic locking. I'm going to start over in more detail and try to leave less scope for misinterpretation. Thanks to all for your comments, especially Jonathan Lewis who saved me from some technical doubts. "Optimistic locking" is a type of solution to the problem of "lost updates". So what do we mean by "lost update", anyway?

The Eagerly Awaited Internet Trends Report 2017

Mary MeekerEvery year, Mary Meeker – partner at Kleiner Perkins Caufield & Byers – releases her ‘Internet Trends Report’. It is probably the most eagerly awaited slide deck of the year (alongside Stacey Harris’ HR Systems Survey and Research report – which if you haven’t yet filled it in, you can do so here). Mary’s Internet Trends report gives a facts and figures based summary of the current state of the marketplace, and predicts how (more...)

SQL Logic Overkill, again …

It’s interesting to watch people try to solve problems. For example, in a lab exercise that I wrote the simple fix is to replace an external file value with a scalar subquery in an INSERT statement. There’s even a hint about how to fix the external file value in the CSV file.

The approach here was interesting and worked. However, it’s wrong on two levels:

INSERT INTO transaction
(SELECT   transaction_s1.nextval
 ,        tr.transaction_account
 ,         (more...)

Free Oracle HCM Cloud backgrounds

It’s a common practice to change the background colour of your environments to give a visual clue which is which. This helps reduce confusion and lessens the risk of entering test data into Production.

Whilst the core project team might easily remember which colour corresponds to which environment (e.g. blue=Prod, red=Dev, green=Test) it’s not so easy for more occasional users. There is a solution for this.

We’ve created some semi-transparent backgrounds that prominently feature (more...)

CSV parsing and tokenizing strings

Most of you will be familiar with the “Comma Separated Values” data format. It is used in spreadsheets and other places to store ordered lists of character data. The delimiter is typically a comma and if a comma is in a list item the item as a whole needs to be quoted, typically with double quotes.



is actually just three items


Also, if we wish to include a double-quote in (more...)

Optimistic Locking with one Timestamp?

A reader called chris asked me a good question about optimistic locking: why not use a “user-defined” scn (e.g. timestamp) as an extra column to achieve the same goal as ORA_ROWSCN? Well, chris, you'd have to use one per row, not one per transaction.

More on Optimistic Locking with ORA_ROWSCN

Thanks to comments by Tony Hasler and pingbacks from Jeff Kemp, here's more detail on how optimistic locking works with SCNs, especially with respect to "restarts" during update.

I Am Speaking at OTN Yathra 2017

RSS content

The Oracle ACE directors and Oracle Volunteers  in the region are organizing their third evangelist event called ‘OTNYathra 2017’ during the month of June 2017 in a time period of 3 weeks. This yathra, managed by ACE directors and Oracle Volunteers of the region, is to travel across the country covering over six major IT focused cities (Chennai, Bangalore, Hyderabad,  Pune, Mumbai and Gurgaon) . It aims  to bring the Oracle community together, giving them awareness (more...)

EBS 12.1.3 Data masking issue with

I tried to data mask the EBS 12.1.3 data with database version but After i masked, I can’t open the application because of SYSADMIN and Guest user was missed. So I raised SR, As per support we need to upgrade database version to otherwise we need to do backport activity. If your database version is, you need to check with Oracle (more...)



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Cedar’s Oracle Talent Acquisition Cloud Event / Team

Earlier this week Cedar held its Oracle Talent Acquisition Cloud event in Oracle’s London City office. We have a really strong team of UK-based Talent Acquisition specialists within our ranks:

Taleo Team 2 (plain background)

Jo, Prachi, Marc and Mel are all experts in the various aspects of Oracle Talent Aquisition Cloud – Taleo Recruit, Sourcing and Onboarding – and Cedar has multiple implementations under our belt covering all of the above products, so we were able to put on (more...)

Question: Table names singular or plural?

Yesterday I put a question on twitter, to find out what others prefer: table names using singular or plural form. I expected one or two replies, not an avalanche :-)

As expected there were all kind of replies going either singular or plural. Some (more...)

toad and oracle client are getting ora-12560 tns protocol adapter error after upgraded windows 10

Yesterday morning I came to office, One of my colleague complaint, My toad not working , I am getting “ora-12560 tns protocol adapter error” while connecting to target database through toad.

I asked him when was this issue started , He said, After upgraded my pc to windows 10. I am getting this issue. I told him, My pc also upgraded to windows 10 but I am not getting this issue. I can able to (more...)

benchmarking your disks


While at Delphix, we did a lot of storage benchmarking. The I/O response times of Delphix depends, as one would logically imagine, heavily on the underlying disks. Sure Delphix can cache a lot ( with 1 TB of ram and 3x compression that’s 3TB and that 3TB can be shared by 10 or a 100 copies being the equivalent to 30TB or 300TB of databases) but really there will always be important I/O coming (more...)