Vishal Desai systematically troubleshooted an interesting case where the initial symptoms of the problem showed a spike of enq: SQ – contention waits, but he dug deeper – and found the root cause to be quite different.
I’ve updated some of my ASH scripts to use these 4 arguments in a standard way:
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)
18-19 Feb 2015: RMOUG Training Days (in Denver)
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).
Here’s where I will hang out (and in some cases speak) during the OOW:
Sunday, Sep 28 3:30pm – Moscone South – 310
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 performance improvements by making small changes.
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.
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.