Performance

Analyzing easily the blocked process report

Which DBA has not yet face a performance problem issued by several blocked processes? In reality, I’m sure a very little number of them. Troubleshooting a blocked issue scenario is not always easy and may require to use some useful(…)

Generic query for multicriteria search – part II: BIND_AWARE (Adaptive Cursor Sharing)

By Franck Pachot . In the previous post I explained the performance issue encountered when using a generic query to deal with optional search criteria on multiple columns. The statement was shared by all executions, was marked as(…)

Never gather WORKLOAD stats on Exadata…

By Franck Pachot . For Exadata, oracle has introduced an ‘EXADATA’ mode which sets a high transfer rate (with IOTFRSPEED as in NOWORKLOAD statistics) and set a MBRC (as in WORKLOAD statistics). Those values are set rather than gathered(…)

IOUG Collaborate #C15LV

By Franck Pachot . The IOUG – Independant Oracle User Group – has a great event each year: the COLLABORATE. This year it’s in April 12-16, 2015 at The Mandalay Bay Resort & Casino in Las Vegas. I’ll be(…)

When to gather workload system statistics?

By Franck Pachot . This month we started to give our Oracle Tuning Workshop. And with a new workshop comes new questions. We advise to give to the optimizer the most accurate statsistics that we can have. That(…)

Don’t forget to configure Power Management settings on Hyper-V

Recently I had the opportunity to audit a SQL Server database hosted on a Hyper-V 2012 cluster. I noticed that the guest operating system had the Power Plan configured to High performance. This is great thing but when I talked to(…)

MySQL versions performance comparison

This blog aims to make a performance comparison between the different MySQL versions/editions and also comparing the differents MySQL forks such as Percona Server and MariaDB.  Indeed number of improvements as been done to innodb storage engine in the last(…)

SQL Server & memory leak: Are you sure?

I have recently come across an issue with one of my customer that told me that their SQL Server 2008 R2 instance had a memory leak. These are strong words! The server has 64 GB of RAM and the(…)

What about ALTER INDEX … SHRINK SPACE ?

By Franck Pachot . I have recently published a script to check index fragmentation. But then, do you COALESCE or REBUILD? Well, there also is another option: ALTER INDEX SHRINK SPACE. Let’s compare all those index defragmentation operations.

SQL Patch: Another way to change the plan without changing the code

Recently, at a customer site, I faced a performance issue. However, as often the statement is embedded in the application so it’s not possible to rewrite the query. In this blog post, we’ll change the execution plan to solve the(…)