There are already a lot of blogposts and presentations done about Hybrid Columnar Compression and i am adding one more blogpost to that list. Recently i was doing some small tests one HCC and noticed that that inserts on a HCC row didn’t got compressed and yes i was using direct path loads:
DBA@TEST1> create table hcc_me (text1 varchar2(4000)) compress for archive high;
KJJ@TEST1> insert /*+ append */ into hcc_me select dbms_random.string('x',100) (more...)
We have migrated a number of our databases from non-Exadata servers to the Exadata Database Machine using the “RMAN 11g Duplicate standby from Active database” method. After creating a Dataguard Database, during a narrow maintenance window, we performed a failover of the database to the one Exadata Database Machines in the cluster. Below are the […]
The post The Step-by-Step Guide to Migrating to an Exadata Database Machine appeared first on VitalSoftTech.
I noticed something for the first time tonight when I was playing around in the Enkitec lab – something that I have been doing wrong for a while. When working in the lab, I often rely on the crsctl command to shut down the entire cluster stack for me. It’s really easy to use “crsctl stop cluster -all” followed by “dcli -l root -g ~/dbs_group /u01/app/126.96.36.199/grid/bin/crsctl stop crs” to get everything down (more...)
Yes that is true, i said it, cellcli can lie to you there are some special cases were the output of cellcli is not the reality and you should double check it’s output with your standard OS tools. So this the output if dcli calling cellcli on an Exadata rack from an client:
[root@dm01db01 ~]# dcli -g cell_group -l root cellcli -e list cell attributes cellsrvStatus,msStatus,rsStatus
dm01cel01: running running running
dm01cel02: running running running
We had a client that was running into a strange issue on their Exadata where new connections coming in through the SCAN were failing. After doing some troubleshooting, it was discovered that it was related to one of the SCAN listeners not properly accepting requests from new sessions. The VIP and listener were running, and everything looked normal.
We had the following SCAN setup:
I’ve previously written about a problem I encountered when kdump is configured to write to an NFS location with UEK (in Exadata software version 188.8.131.52.1). I’m please to report that the root cause of the problem has been identified and there is a very simple workaround.
There were some frustrating times working this particular SR, the most notable being a response that was effectively, “It works for me (and so I’ll (more...)
Exadata Maximum Availability Architecture from Yunus Emre Baransel
There were problems that affected UEK and NFS when 184.108.40.206.1 was initially released (as covered by Andy Colvin). As mentioned in the comments of Andy’s post: Oracle released an updated ISO with fixes for this problem (patch 16432033).
There were also problems with kdump not (more...)
Recently we noticed that imageinfo was displaying the following information at a customers site. Imageinfo was not displaying data i suspected, so a quick little blogpost about what was going on there.
[root@dm01db01 ~]# dcli -g /opt/oracle.SupportTools/onecommand/dbs_group -l root "imageinfo | grep 'Image version'"
dm01db01: Image version: 11.2. (more...)
With cellcli you can run the calibrate command, this will measure the performance of your harddisks and flashcards. It will eventually report to you the throughput and amount of IOPS that was measured during the calibrate, it will also report to you which luns are not performing up to par.
An Oracle Exadata Full Rack consists of 8 DB compute nodes. Oracle has shifted the strategy to patching the exadata in 220.127.116.11.0 onwards to using Yum as the method of patching. the Quarterly Full Stack does not include the DB Compute nodes patches anymore. So that (more...)
I’ll be co-speaking with Tyler Muth at E4 and we will be talking about Performance Visualization… some of you may already know that I’m really a big fan of Tableau and just to give you an example on what the tool can do I’ve consolidated all the different viz that (more...)
I have announced my webinar on Oracle ZFS Storage Appliance for Exadata Backup & Recovery in NYOUG DBA webinar series. You can download webinar slides and voice recod from NYOUG web site
In Friday December 14, 2012 at 12:00 PM -1:00 PM EDT I will be giving a webinar for NYOUG SIG with the following abstract
When it comes to the backup and recovery infrastructure of the Exadata Database Machine, conventional solutions often have only limited performance to keep up with Exadata throughput, whereas Oracle ZFS Storage Appliance can be configured as a very fast, capable, and easy-to-manage backup and recovery solution for any Exadata environment. In this session Husnu Sensoy will describe some of the configuration possibilities of the ZFS Storage Appliance to create a flexible backup and recovery environment for Exadata, (more...)
I’ve been working a lot with graphing DB and OS metrics in R. I find it especially useful in Exadata POVs (proof of value) to gather and graph the oswatcher vmstat files for the compute nodes and iostat for the cells. For an example, take a look at this graph (PDF, 168 KB) of what [...]
With the announcement Exadata X3, Oracle has introduced a new feature called “FlashCache Writeback” to allow writes to cell Flash Cache (aka Exadata Smart FlashCache) in WriteBack mode. Earlier with WriteThrough mode, writes were not written to FlashCache, instead they were written directly to cell disks. Exadata software used to decide whether to cache these writes back into FlashCache or not. In WriteBack mode, writes are written to cell FlashCache and acknowledgement is given back to calling process as soon as data is written to flashcache. Exadata Server software de-stages the dirty writes in flashcache to spinning disks in the (more...)
I’ll be speaking at the Enkitec Extreme Exadata Expo (E4), August 13-14 in Dallas Texas (you can also attend virtually). They’ve recruited some of the top names from community including keynote speaker Andrew Mendelsohn, Arup Nanda, Cary Millsap, Jonathan Lewis, Karen Morton, Maria Colgan, Kerry Osborne and Tanel Põder. I left a lot of names off the list, many of which you probably [...]
I’ll be co-speaking with Randy Johnson (one of the authors of Expert Oracle Exadata) at E4 to share about the war stories and detail on a bunch of technical stuff on a Peoplesoft and BIEE consolidation project we had on one of our clients. See the abstract below:
Randy Johnson & Karl Arao
A PeopleSoft & OBIEE Consolidation Success Story
In today’s competitive business climate companies are under constant pressure to reduce costs without sacrificing quality. Many companies see database and server consolidation as the key to meeting this goal. Since its introduction, Exadata has become the obvious choice for (more...)
Last week I had a lengthy post at oracle-l that tackles Calibrate IO, Short Stroking, Stripe size, UEK kernel, and ASM redundancy effect on IOPS Exadata which you can read here
followed by interesting exchange of tweets with Kevin Closson here (see 06/21-22 tweets) which I was replying in between games at UnderwaterHockey US Nationals 2012 which we won the championship for the B division I have my awesome photo with the medal here
This post will detail on the ASM redundancy/parity effect on IOPS… if… by changing the ASM redundancy (external, normal, and high) will it decrease the workload (more...)