OraNA :: Oracle News Aggregator

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) (more...)

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.

The exadisktopo.sql script shows all disks starting from the ASM diskgroup layer, going deeper and deeper (more...)

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:

SQL> @desc v$cell_thread_history
           Name                            Null?    Type
           ------------------------------- -------- ----------------------------
    1      CELL_NAME                                VARCHAR2(1024)
    2      SNAPSHOT_ID                              NUMBER
    3       (more...)

Check out the extensive slide deck (over 500 slides) about upgrading techniques to Oracle 11.2, by Oracle Corp (Roy Swonger and Mike Dietrich):

• https://blogs.oracle.com/UPGRADE/entry/new_version_of_the_huge

It has lots of examples (from real customer upgrade cases) in it.

Thanks to Randolf Geist for telling me about this.

You can (more...)

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):

The top google hits (more...)

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:

• 16 April 2013 – UKOUG Engineered Systems Summit
  • London, UK
  • I will talk about the common Exadata (more...)

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:

SQL> @hint merge

NAME                                                             VERSION                   VERSION_OUTLINE           INVERSE
---------------------------------------------------------------- ------------------------- ------------------------- ----------------------------------------------------------------
MERGE_CONST_ON                                                   8.0.0
MERGE_AJ                                                         8.1.0                     8. (more...)

If you attended my Exadata hacking session today, you saw me using the cellver.sql script which lists some basic configuration info about the currently connected storage cells:

SQL> @exadata/cellver
Show Exadata cell versions from V$CELL_CONFIG....

CELLNAME             CELLSRV_VERSION      FLASH_CACHE_MODE     CPU_COUNT  UPTIME               KERNEL_VERSION                 MAKE_MODEL
-------------------- -------------------- -------------------- ----------  (more...)

Jonathan Lewis has already written about this behavior from the angle of PARALLEL hints.

I’m writing a similar article just because the word FORCE in the ALTER SESSION FORCE PARALLEL QUERY syntax. Force should mean that some behavior would always happen (when possible), right? Let’s test:

SQL> CREATE TABLE t  (more...)

I don’t have much time for a thorough blog post, so I’ll just paste in an example output of my asqlmon.sql script, which uses ASH sql_plan_line columns for displaying where inside your execution plan response time has been spent. Why not just use Oracle’s own SQL Monitoring reports? Well, SQL monitoring is meant for “long running” queries, which are not executed very frequently. In other words, you can’t use SQL Monitoring for drilling down into your frequently executed OLTP-style SQL. I am copying my recent post to Oracle-L mailing list here too:

The main performance impact of the old (more...)