Just a little reminder – next week (10-11th June) I’ll be delivering my last training session before autumn – a short 1-day (2 x 0.5 days actually) seminar about Getting the Most Out of Oracle’s Active Session History. In the future it will act as sort of a prequel (or preparation) for my Advanced Oracle Troubleshooting class, as the latter one deliberately goes very deep.
One of the most common Exadata performance problems I see is that the direct path reads (and thus also Smart Scans) don’t sometimes kick in when running full scans in serial sessions.
About 5 years ago I wrote about the risks that connecting to Oracle processes via debuggers may cause and what are (in my opinion) the safer and less safer options for taking stack samples from running Oracle processes.
In the end of that article I listed different options for getting a stack traces and whether they were safe or not.
In the previous post I explained how to list Exadata disk layout and topology details with the exadisktopo scripts, in this post I’ll introduce one celldisk overview script, which I use to quickly see the celldisk configuration, specs and error statuses. The cellpd.sql script (Cell Physical Disk) will show the following output:
Here are two more Exadata scripts for listing the end-to-end ASM<->Exadata disk topology from V$ASM_ views and from V$CELL_CONFIG. These scripts see both the ASM level layout and the storage cell-level disk topology.
Did you know that there’s something like Active Session History also in the Exadata storage cells? ;-)
The V$CELL_THREAD_HISTORY view is somewhat like V$ACTIVE_SESSION_HISTORY, but it’s measuring thread activity in the Exadata Storage Cells:
Check out the extensive slide deck (over 500 slides) about upgrading techniques to Oracle 11.2, by Oracle Corp (Roy Swonger and Mike Dietrich):
It has lots of examples (from real customer upgrade cases) in it.
I’m writing this (unusual) post as I am a long time Gmail user and recently I’ve seen plenty of people & articles complain about the Gmail’s new compose window (the one that shows up as a small hovering window in the bottom right of your screen):
I will be doing a lot of (Exadata) talking and teaching in the coming months. Here’s a list of events where you’ll see me speaking, teaching, hacking, learning and hopefully also drinking beer:
You may have used the Oracle 11g V$SQL_HINT view already – it displays all the valid hints (both documented and undocumented ones) available in your Oracle version, for example: