Here are the slides of a presentation I did at the IOUG Virtual Exadata conference in February. I’m explaining the basics of some new Oracle 12c things related to Exadata, plus current latest cellsrv improvements like Columnar Flash Cache and IO skipping for Min/Max retrieval using Storage Indexes:
Note that Christian Antognini and Roger MacNicol have written separate articles about some new features:
Here’s where I’ll hang out in the following months:
11-12 Feb 2015: IOUG Exadata SIG Virtual Conference (free online event)
- Presentation: Exadata Performance: Latest Improvements and Less Known Features
- It’s a free online event, so sign up here
18-19 Feb 2015: RMOUG Training Days (in Denver)
- I won’t speak there this year, but plan to hang out on Wednesday evening and drink beer
- More info here
1-5 March 2015: Hotsos Symposium 2015
This is the first entry in a series of random articles about some useful internals-to-know of the awesome Oracle Database In-Memory column store. I intend to write about Oracle’s IM stuff that’s not already covered somewhere else and also about some general CPU topics (that are well covered elsewhere, but not always so well known in the Oracle DBA/developer world).
Before going into further details, you might want to review the Part 0 of this series and also our (more...)
Here’s where I will hang out (and in some cases speak) during the OOW:
Sunday, Sep 28 3:30pm – Moscone South – 310
Monday, Sep 29 8:30am – 4:00pm (more...)
Despite the title, this is actually a technical post about Oracle, disk I/O and Exadata & Oracle In-Memory Database Option performance. Read on :)
If a car dealer tells you that this fancy new car on display goes 10 times (or 100 or 1000) faster than any of your previous ones, then either the salesman is lying or this new car is doing something radically different from all the old ones. You don’t just get orders of magnitude (more...)
Enkitec folks have been beta testing the Oracle Database 12c In-Memory Option over the past months and recently the Oracle guys interviewed Kerry Osborne, Cary Millsap and me to get our opinions. In short, this thing rocks!
We can’t talk much about the technical details before Oracle 126.96.36.199 is officially out in July, but here’s the recorded interview that got published at Oracle website as part of the In-Memory launch today:
Here’s a little known feature of Exadata – you can use a Bloom filter computed from a join column of a table to skip disk I/Os against another table it is joined to. This not the same as the Bloom filtering of the datablock contents in Exadata storage cells, but rather avoiding reading in some storage regions from the disks completely.
So, you can use storage indexes to skip I/Os against your large fact table, based on a (more...)
Enkitec is the best consulting firm for hands on implementation, running and troubleshooting your Oracle based systems, especially the engineered systems like Exadata. We have a truly awesome group of people here; many are the best in their field (just look at the list!!!).
This is why I am here.
This is also why Accenture approached us some time ago – and you may already have seen today’s announcement that Enkitec got bought!
There was an interesting question in Oracle-L about the JOXSHM_EXT_* files in /dev/shm directory on Linux. Basically something like this:
$ ls -l /dev/shm/* | head
-rwxrwx--- 1 oracle dba 4096 Apr 18 10:16 /dev/shm/JOXSHM_EXT_0_LIN112_1409029
-rwxrwx--- 1 oracle dba 4096 Apr 18 10:16 /dev/shm/JOXSHM_EXT_100_LIN112_1409029
-rwxrwx--- 1 oracle dba 4096 Apr 18 10:16 /dev/shm/JOXSHM_EXT_101_LIN112_1409029
-rwxrwx--- 1 oracle dba 4096 Apr 18 10:23 /dev/shm/JOXSHM_EXT_102_LIN112_1409029
-rwxrwx--- 1 oracle dba 4096 Apr 18 10:23 /dev/shm/JOXSHM_EXT_103_LIN112_1409029
-rwxrwx--- 1 (more...)
If you haven’t read them – here are the previous articles in Oracle memory troubleshooting series: Part 1, Part 2, Part 3.
Let’s say you have noticed that one of your Oracle processes is consuming a lot of private memory. The V$PROCESS has PGA_USED_MEM / PGA_ALLOC_MEM columns for this. Note that this view will tell you what Oracle thinks it’s using – how much of allocated/freed bytes it has kept track of. While (more...)