Posts Categorized: Pythian
Recently, I was asked to take a look at a query processing part of a client’s application which had started to perform slowly after the application had a maintenance downtime. The idea behind the processing was quite simple.The trick was to add a (redundant) CASE PROCESSED WHEN 0 THEN MOD(SUBS_ID, 7) end expression into ORDER BY clause..In this post I show you how I came to this solution.
The 58th edition of Log Buffer, the weekly review of database blogs, has been published by Jay Pipes (a.k.a J.Pipes) of MySQL AB on Design, Develop, Discover, Define.
For those of you expecting your weekly dose of Log Buffer in this space, it has been unavoidably delayed. It will appear around 3PM Eastern Time today. Hang tight!
So what is SQL Performance Analyzer (SQLPA)? The DBMS_SQLPA package enables you to register and compare the statistics of several SQL query executions stored in an SQL Tuning Set (STS). With SQL Performance Analyzer, you can compare the executions of queries before and after you make some changes to your database. As you might guess, I’m going to illustrate this new feature in Oracle 11g with a simple example.
So Management chooses to review the documentation generated from your database failover test and see that the time to switchover is slow and that there is still a possibility of losing some data. Enter standby redo logs. Rather than regurgitate the documentation, I have attached the links to the specific parts of the documentation. Since I’m focused on providing ways for you to “get the job done”, I have also included some SQL that uses dynamic SQL to generate a series of ALTER DATABASE ADD STANDBY LOGFILE commands to run on both the primary and standby databases. Have a look.
Wouldn’t “Automatic SQL Plan Management” be the 11g “killer app”? I’m just wondering… be careful it is part of Oracle Tuning Pack 11g! Before you answer this question, lets illustrate with an example how the “non-automatic”, “no tuning Pack” SQL Plan Management works.
About six weeks ago, I wrote, with my colleagues here at Pythian, an open letter to Larry Ellison, imploring him and Oracle to free API-level access to Automated Workload Repository (AWR) and Active Session History (ASH). This letter has received amazing support from the community, with 158 “signatories” at last count, and many other positive comments.
We received an informal but cordial response from Oracle two or three days after we couriered the letter to them, which said we could expect a formal reply soon.
“Real Time SQL Monitoring” is a 11g Tuning Pack new feature. You can easily access it when the Tuning Pack is set. Anyway, It’s very impressive even if it doesn’t look to be fully functional (Is it me ?). I guess Enterprise Manager provides a fantastic GUI for this feature. This post is for you if you don’t always use it…
I just read a fascinating article on clustering architectures for databases from Kevin Closson of Polyserve (now HP). All I can say is that he has one of the most informed and incisive views and insights on clustering, SMP, high-availability and high-performance environments in the industry. I thought I would share this with the broader community because I think a lot of MySQL, SQL Server and EnterpriseDB folks who need to read this and think about this subject might otherwise miss it, simply because they may not be regular readers of Kevin’s blog.
Hubert Depesz Lubaczewski has published the 57th edition of Log Buffer, the weekly review of database blogs, on .