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...)
This is a panel where Andy Colvin, Kerry Osborne and I will discuss what has changed in Exadata since writing the 1st edition of the Expert Oracle Exadata book (yes, we are working on the 2nd edition, stay tuned!)
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 18.104.22.168 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!!!).
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...)