Parallel Costs

While creating a POC of a SQL rewrite recently I received a little surprise as I switched my query from serial execution to parallel execution and saw the optimizer’s estimated cost increase dramatically. I’ll explain why in a moment, but it made me think it might be worth setting up a very simple demonstration of the anomaly. I created a table t1 by copying view all_source – which happened to give me a table with about 100,000 rows and 1117 (more...)

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APPEND and PARALLEL

APPEND hint in oracle is very useful, there are many benefits

Fragmented data loading – data will clustered above the HWM so that similar data will be together. Otherwise Oracle will place the records in blocks using PCT_FREE rule

  • No undo will be generated – in large direct path insert will free up large amount of data blocks
  • Less CBC latches (because of no UNDO blocks), less CPU usage
  • Readers need not undo the records, (more...)

Upcoming Webinar: Innovation in Managing the Chaos of Everyday Project Management

On Thursday, December 4th from 1 PM-2 PM CST, Fishbowl Solutions will hold a webinar in conjunction with Oracle about our new solution for enterprise project management. This solution transforms how project-based tools, like Oracle Primavera, and project assets, such as documents and diagrams, are accessed and shared.

With this solution:

  • Project teams will have access to the most accurate and up to date project assets based on their role within a specific project
  • Through (more...)

Upgrading to 11.2.0.4 – Dictionary View Performing Poor

Just a quick blog post on things you might see after upgrading to 11.2.0.4. We recently upgraded database from 11.2.0.3 to 11.2.0.4 and query on some data dictionary views ran too slow.

1. Performace of query on dba_free_space degraded
2. Performance of query involving dba_segments is slow

DEV01> select ceil(sum(b.bytes)/1024/1024) b from sys.dba_free_space b;

Elapsed: 01:31:45.78

Searching MOS pointed to these Doc Ids (more...)

Christmas Masterclass Oracle SOA Suite 12c

On Friday, December 19, AMIS organises a special XMas-terclass on SOA Suite 12.

SOA Suite 12c (June 2014) was a major release for Oracle’s flagship integration product. This release introduces new functionality, higher developer productivity, more robust run-time scalability and performance. 12c brings together development and administration of Service Bus and SOA composite applications, it ships new technology adapters as well as a SDK to develop custom adapters and provides across the stack support for REST-style (more...)

Progress update on my AWR repository

I received an email from a team member yesterday

Have you seen this? https://docs.oracle.com/database/121/TDPPT/tdppt_awr_warehouse.htm

Interesting idea – ever thought of implementing it?

Well of course I have implemented a AWR data repository and I thought I would catch-up on where I am with it and how it is being used.

The database started out on HPUX on 11.2.0.1 about 2 years ago and is now on Linux on 11. (more...)

MAF 2.0 : Loading Images in a Background Process – Part I

Images are heavily used in Mobile apps. For instance a list that contains employees usually shows the images of these employees. This works well when you have a WIFI connection, but what if you are using slower connections ? If you look at a mobile twitter app you will see that, depending on connectivity, images are loaded instantaneously or delayed. In this post I explain how you can load the images of a List in a (more...)

Oracle Big Data Appliance X4-2: First impressions

The last 2 weeks we are lucky enough to have the Big Data Appliance (BDA) from Oracle in our lab/demo environment at VX Company and iRent. In this blog post i am trying to share my first experiences and some general observations. I am coming from an Oracle (Exadata) RDBMS background so i will probably reflect some of that experience on the BDA. The BDA we got here at is a starters rack which consists (more...)

Removing Redundant Startup/Restart for the OMS Service in Windows

I’ve been told many times that the OMS for EM12c can take quite some time to start on Windows.  Some told me it took anywhere from three to up to fifteen minutes and wanted to know why.  I’ve done some research on the challenge and it is a complex one.

Let’s start this post by stating that even though I’m focusing on the OMS service that is part of the Windows installation of EM12c from (more...)

Running Oracle Repository Creation Utility on 64-bit Ubuntu.

Today I needed the Oracle Repository Creation Utility (RCU) on a 64-bit Ubuntu VM. However, if you search the Oracle website, you can only find a 32-bit version of the RCU. I decided to download the 32-bit version instead.

We start the process of running the RCU by unzipping the downloaded file.  Navigate to the folder where the downloaded file is placed and execute the following command:

Running Oracle Repository Creation Utility on 64-bit Ubuntu.

(more...)

rdbms-subsetter

I've never had a tool I really liked that would extract a chunk of a large production database for testing purposes while respecting the database's foreign keys. This past week I finally got to write one: rdbms-subsetter.

rdbms-subsetter postgresql://user:passwd@host/source_db postgresql://user:passwd@host/excerpted_db 0.001

Getting it to respect referential integrity "upward" - guaranteeing every needed parent record would be included for each child row - took less than a day. Trying to get it to also guarantee (more...)

HOWTO: Validate XML content against an XML Schema

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

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...)

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...)

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...)

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...)

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...)

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...)