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Database Feed

Oracle Database, Oracle 10g, Oracle 11g, Oracle XE, Oracle RAC, Oracle Instant Client, Oracle Data Guard and Oracle Exadata resources, news, and support articles.

In Deference

An interesting ‘problem’ surfaced a while ago, one where a user with zero quota on every tablespace could successfully create tables. Of course once it was time to insert data the inserts failed, but this was confusing the user creating the tables. The ‘problem’ stems from enabling deferred segment creation in the database. Let’s see how that can create a confusing situation,

Log parallelism bug now has a number

A few weeks ago I wrote a post about log parallelism causing excessive log file sync waits. Ever since, I’m finding more and more examples how this bug affects OLTP and hybrid databases (and even some data warehouses)!

HOWTO: Validate XML content against an XML Schema

Somewhere on this site is a post regarding how to validate against an XML schema…


If we are dealing with large amounts of data and have to use queries to find count of distinct values of some particular column or group of columns, the new feature APPROX_COUNT_DISTINCT function can be significantly faster than using the traditional COUNT (DISTINCT expr) function with marginal differences in the exact result.

The examples below also show less optimizer cost overhead as well as temporary tablespace space usage as well.

Sample TAPI Apex Application

If you attended my presentation at AUSOUG Perth earlier this month, or if you’ve had a peek at the slides, you may be interested in a more concrete demonstration of the ideas presented. So if you’d like to install and play with a sample application that includes a TAPI generator, feel free to download this.

Rollback to Savepoint Does Not Release Locks

I read that rolling back to a savepoint releases locks. This sounded reasonable so I decided to check it out in an Oracle 11.2 database. I logged in as user John (in blue) and noted my SID for future reference. Then I created a table, inserted a row, committed the change and created a savepoint.

NoCOUG watchers protest despicable tactics being used by NoCOUG management

FOR IMMEDIATE RELEASE NoCOUG watchers protest despicable tactics being used by NoCOUG management SILICON VALLEY (NOVEMBER 13, 2014) – Veteran NoCOUG watchers all over Northern California have been protesting the despicable tactics being used by NoCOUG management to lure Oracle Database professionals to the NoCOUG conference at the beautiful eBay Town Hall next week. Instead […]

ORA-00600 – [kfnsInstanceReg00]

An interesting case of ORA-600 :)

I was paged for standby lag and started looking into the issue. The db version was version. Standby was lagging behind by 36 archives

ORA-64359: INMEMORY clause may not be specified for virtual columns

The title above gives you immediate knowledge of the end result of this post. If you want to know the whys and wherefores then by all means read on.

I was on a call yesterday listening to a presentation on Database 12c new features. The In-Memory Column Store received a lot of interest, as did the new JSON functionality.

12c metadata only default values for NULL columns part 2

Yesterday I attended #cluboracle event in London (I highly recommend this event! ... but I don't recommend Thameslink train service :) ). In this event one interesting discussion popped up regarding 12c. I've already written about this feature, so in this post I'll clarify some points as I understand them and test out a few more things.

Here is a quote from my last post summing up my findings so far:

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