Search

Top 60 Oracle Blogs

Recent comments

July 2014

Impugn My Character Over Technical Points–But You Should Probably Be Correct When You Do So. Oracle 12c In-Memory Feature Snare? You Be The Judge ‘Cause Here’s The Proof.

Press Coverage at The Register: Click here.

Executive Summary

This blog post offers proof that you can trigger In-Memory Column Store feature usage with the default INMEMORY_* parameter settings. These parameters are documented as the approach to ensure In-Memory functionality is not used inadvertently–or at least they are documented as the “enabling” parameters.

Oracle Database 12c In-Memory Feature. Enabled, Used or Confused? Don’t Be.

Enabled By Default. Not Usable By Default.

Series Links: Part I, Part II.

It was my intention to only write 2 installments on my short series about Oracle Database 12c In-Memory Column Store feature usage. My hopes were quickly dashed when the following developments occurred:

1. A quote from an Oracle spokesman cited on informationweek.com was pulled because (I assume) it corroborated my assertion that the feature is enabled by default. It is, enabled by default.

To subset or not to subset

There was a problem at a customer in application development where using full copies for developers and QA was causing excessive storage usage and they wanted to reduce costs , so they decided to use subsets of the production development and QA
  • Data growing, storage costs too high, decided to roll out subsetting
  • App teams and IT Ops teams had to coordinate and manage the complexity of the  shift to subsets in dev/test
  • Scripts had to be written to extract the correct and coherent data, such as correct date ranges and respect referential integrity
  • It’s difficult to get 50% of data 100% of skew instead of  50% of data 50% of skew
  • Scripts were constantly breaking as production data evolved requiring more work on the subsetting scripts
  • QA teams had to rewrite automated test scripts to run correctly on subsets
  • Time lost in ADLC, SDLC to enable subsets to work (converting CapEx into higher OpEx) put pressure

Remote Cloning of PDBs and Non-CDBs (12.1.0.2)

I mentioned in a previous post that I would be revisiting some of my existing multitenant articles to include some of the features introduced in the 12.1.0.2 patch. Here’s one of them.

Analogy

So 12.1.0.2 is out with a number of interesting new features, of which the most noisily touted is the “in-memory columnar storage” feature. As ever the key to making best use of a feature is to have an intuitive grasp of what it gives you, and it’s often the case that a good analogy helps you reach that level of understanding; so here’s the first thought I had about the feature during one of the briefing days run by Maria Colgan.

“In-memory columnar storage gives you bitmap indexes on OLTP systems without the usual disastrous locking side effects.”

Oracle Licensing : It’s Your Responsibility to Comply

This little moan was inspired by some posts by Kevin Closson.

Beauty of command line - OEM 12c

Why all software should have a command line and automation plugin ? Answer is simple - if you have to repeat number of operation for different targets - scripts can help you save your precious time.

I really enjoy a fact that Oracle added a command line to Oracle Enterprise Manager line, and now you can script lot of boring tasks like adding new administrator to list of users who can access Named Credentials.

To add new admin (przepiorom) it's enough to run the following script
 

add_privs.sh przepiorom

Beauty of command line - OEM 12c

Why all software should have a command line and automation plugin ? Answer is simple - if you have to repeat number of operation for different targets - scripts can help you save your precious time.

I really enjoy a fact that Oracle added a command line to Oracle Enterprise Manager line, and now you can script lot of boring tasks like adding new administrator to list of users who can access Named Credentials.

To add new admin (przepiorom) it's enough to run the following script
 

add_privs.sh przepiorom

Oracle Database 12c Release 12.1.0.2 – My First Observations. Licensed Features Usage Concerns – Part II.

Preface

In this post you’ll see that I provide an scenario of accidental paid-feature “use.”  The key elements of the scenario are: 1) I enabled the feature (by “accident”) but 2) I didn’t actually use the feature because I neither created nor altered any tables.

Finding the blocking SQL in a lock wait

#555555;">One of my pet peeves on Oracle is the inability to find out what SQL took out a lock that another user is waiting. It’s easy to find the waiting user and their SQL with v$session by looking at v$session.event where the event is an “enqueue” (v8 and v9) or “enq: TX – row lock contention” and then looking up their SQL via the v$session.sql_hash_value which joins to v$sql.hash_value for the v$sql.sql_text.