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)! For example, my current employer is a large organization that has several thousand databases (set up at different time by different teams), and according to the studies I conducted on a sample of a few dozen databases, (more...)

HOWTO: Validate XML content against an XML Schema

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

Check out the new Oracle help web site

I found a broken link to an Oracle help document in one of my posts and when I went to the Oracle 12c database documentation to find the new URL to put in my post I found that Oracle had totally revamped their online manuals.

Here is a link to the new high level Oracle help site: url

I’ve only looked at it for a few minutes and can’t say whether I like it or (more...)

OT: Toad University at NoCOUG fall conference

The NoCOUG fall conference featuring Toad University will be held at the eBay Town Hall in San Jose, CA on Wednesday, November 19. If you have never attended a NoCOUG conference in the 28-year history of NoCOUG—yes, that’s how long NoCOUG has been around—you’re invited to attend the upcoming conference for free. Simply send your name, title, and company to contact_nocoug@nocoug.org.

Toad Overview and Roadmap for DBAs, Developers, and Data Analysts—Daniel Norwood & (more...)

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. Finally I updated the row but did not commit the change, thus setting up a lock:
 

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 11.1.0.7.0 version. Standby was lagging behind by 36 archives

SQL> @mrp

   INST_ID PROCESS   STATUS          THREAD#  SEQUENCE#     BLOCK# DELAY_MINS
---------- --------- ------------ ---------- ---------- ---------- ----------
         1 MRP0      WAIT_FOR_LOG          1     568330          0          0 


   INST_ID PROCESS   STATUS          THREAD#  SEQUENCE#     BLOCK# DELAY_MINS
---------- --------- ------------ ---------- ---------- ---------- ----------
         1 RFS       IDLE                   (more...)

Will the REAL Snap Clone functionality please stand up?

Every so often our competitors like to spread false information about our solutions so as to gain unfair advantage. I wanted to address this for the Enterprise Manager Snap Clone functionality, so this blog post describes the Snap Clone solution as it currently stands (November 2014).

Let’s start by introducing Snap Clone functionality. I blogged on that a few months back, but a few months can be an eternity in software development terms, so here’s (more...)

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:

This new column seems (more...)

Simple Query to Check if Your EM12c Plugins Are Uptodate

It’s recommended to use latest plugins with EM12c (to minimize bugs, better support for new releases of target etc), and you probably set notifications to get mails about plugin updates, but sometimes you just ignore them because you don’t have time. So you may want to check if any plugins you use have updates. It’s possible to do it using EM12c web interface. All you need is to go to “self update” page, click on (more...)

Active Data Guard 12c New Features – Oracle Day 2014

Sangam 2014

I am back from AIOUG meet “SANGAM 14 – Meeting of Minds” and it was a wonderful experience. Had really nice time meeting some old friends and making few new ones :). I think i should mention here, finally i met Amit Bansal , mind behind http://askdba.org/ . It was fun meeting him :)

It was 3 day conference with

1st day :- Optimizer Master Class by Tom Kyte. It was full day seminar. Learned (more...)

Parallel Fun

As I write, there’s an ongoing thread on Oracle-L that started with the (paraphrased) question: “I’ve got this query that returns 7 million rows; when I change it to ‘select count(*)’ it returns in 4 seconds but when we display the full result set on screen it takes hours, and every second or two the screen pauses; how do I make it go faster.”

The general rapid response was: “You shouldn’t be running 7M rows to a screen (more...)

Making Copies of Copies with Oracle RMAN

I recently had need to make a copy of an image copy in Oracle rman. Since it wasn't immediately obvious to me, I thought it was worth sharing once I had it sorted out. I was familiar with making a backup of a backup, but had never thought about making a copy of a copy.

First you need to create an image copy of your database or tablespace. For the sake of example, I'll make (more...)

Quick Links to Helpful Literature on Oracle Database In-Memory Column Store.

I’m surprised to find that Google is not cleanly ranking the helpful set of blog posts by Oracle’s Maria Colgan on the Oracle Database 12c In-Memory Column Store feature so I thought I’d put together this convenient set of links. Google search seems to only return a few of them in random order.

Over time I may add other helpful links regarding Oracle’s new, exciting caching technology.

Starter Information

Getting Started With Oracle Database In-Memory. (more...)

Audio semi-Visual Presentation on Clustering Data in Oracle

I suppose it had to happen eventually but one of my presentations has ended up on YouTube. It’s a recent presentation I did for the Oracle Midlands user group in September.

The topic is (as the title of this blog post hints at!)Boosting select performance by clustering data. The video consists of the slides I presented, changing as the presentation progresses, with my audio over the top. It goes on for a bit, (more...)

EM12c, Rel. 4, OMS and OMR Health, Part II

There are a large number of “moving parts” when performance tuning or trouble shooting an Enterprise Manager environment.  The new EM performance features, (available in release 12.1.0.4) are there to assist you in understanding the source of the issue and can really make the difference for those that are unfamiliar with the challenges of Weblogic, java, network or other complexities that make up EM12c and aren’t commonly thought of as part (more...)

Why do you need to gather CBO Statistics?

As I help a peer with a SQL Tuning engagement, I face the frequent case of: “We do not want to gather CBO schema object statistics because we don’t want our Execution Plans to change”. Well, the bad news is that: not gathering stats only gives you a false sense of safety because your Execution Plans can change anyways. The reason has to do with Predicates referencing values out of range. Typical cases include range (more...)

GoldenGate not keeping up? Use GoldenGate Range function to split up the process

In most of the environments, one set of OGG processes (1 Extract & 1 Replicat process) is sufficient for change data synchronization. But if your source database generates a huge volume of data then a single process may not be sufficient to handle the data volume. In such a scenario there may be need to […]

The post GoldenGate not keeping up? Use GoldenGate Range function to split up the process appeared first on VitalSoftTech.

Is Oracle Database 12c (12.1.0.2.0) Faster Than Previous Releases?

Is Oracle Database 12c (12.1.0.2.0) Faster Than Previous Releases?


I was wondering if the new Oracle Database 12c version 12.1.0.2.0 in-memory column store feature

will SLOW performance when it is NOT being used. I think this is a fair question because most Oracle Database systems will NOT be using this feature.

While the new in-memory column store feature is significant, with each new Oracle feature there is (more...)