Do you know the difference between exp/imp and expdp/impdp when it comes to importing HCC compressed data in Exadata?
If not, then follow me through two examples. This is on 220.127.116.11/18.104.22.168.1 but applies to all database releases you can have on Exadata. The task at hand is to export a table (which happens to be non-partitioned and HCC compressed for query high) and import it into a different user’s (more...)
I think I’ll create this as a sticky post as soon as I found out how this works in WordPress :) This is going to be a list of my public appearances in 2015.
Paris Oracle Meetup
The next time I’ll be speaking publicly is on April 15 in Paris at the Paris Oracle Meetup. Many thanks go to @Ycolin and @BertrandDrouvot for inviting me to my first ever presentation in France! I am very (more...)
In part 1 of the series I tried to explain (probably a bit too verbose when it came to session statistics) what the effect is of delayed block cleanout and buffered I/O. In the final example the “dirty” blocks on disk have been cleaned out in the buffer cache, greatly reducing the amount of work to be done when reading them.
Catching up with now, and direct path reads. You probably noticed that the migration (more...)
Travel time is writing time and I have the perfect setting for a techie post. Actually I got quite excited about the subject causing the article to get a bit longer than initially anticipated. In this part you can read about block cleanouts when using buffered I/O. The next part will show how this works using direct path reads and Smart Scans.
The article ultimately aims at describing the enhancements Exadata brings to the table (more...)
Having read the excellent post “Demystifying ASM REQUIRED_MIRROR_FREE_MB and USABLE_FILE_MB” again by Harald von Breederode I wanted to see what happens if you create a setup where your usable_file_mb is negative and you actually have to rebalance after a fatal failgroup error. I am using 22.214.171.124.0 on Oracle Linux 6.6/UEK3 in a KVM in case anyone is interested. I/O times aren’t stellar on that environment. It’s Oracle Restart, (more...)
This is a common problem I have and I never write it down (except now). For example, today I wanted to know what the valid parameters for _serial_direct_read were:
SQL> select * from v$parameter_valid_values where name ='_serial_direct_read';
no rows selected
OK so if Oracle doesn’t tell me then maybe I can work it out? Getting the view_text has worked in the past:
SQL> select view_name, text_vc from dba_views where view_name like '%PARAMETER_VALID_VALUES'
Adaptive plans are one of the coolest new optimiser features in Oracle 12c. If you haven’t seen or heard about them in detail I recommend the following resources:
There is a caveat with this though: if your tuning script relies on (more...)
In the first part of the article series you could read how a kickstart file made the installation of Oracle Linux 7 a lot more bearable. In this part of the series it’s all about configuring the operating system. The installation of Grid Infrastructure and the Oracle database is for another set of posts.
There are quite some differences between Oracle Linux 6 and 7
To me the transition from Oracle Linux 6 to 7 (more...)
Now that 126.96.36.199 is certified on RedHat Linux 7 and spin-off environments it’s time to test the installation of RAC on such a system.
The installation of the OS is different from Oracle Linux 5 and 6-with these distributions was very straight forward how to install the operating system the method has changed significantly in release 7. I won’t cover the complete installation here, as always Tim Hall was quicker than me, (more...)
Thanks to Andy Colvin (@acolvin) and the Enkitec lab I have been able to get my hands on an ODA X4-2. And since that’s a lot quieter than turning on my own lab server, and also a lot faster I used the environment to test RAC One Node in 188.8.131.52.1. I recently had a question from a customer about the usefulness of the solution and what it brings to the HA (more...)