Kevin Kempf's Blog

May 11, 2010

Advanced Compression and Interface Tables

Filed under: 11g, 11i, advanced compression — kkempf @ 2:57 pm

Advanced Compression – More Stories from the Front Lines

We’re several months into advanced compression, after the Dataguard bug/debacle, and we’re really quite happy with the product.  Practically speaking, the ERP runs from the buffer cache, and thus our I/O is down to a trickle.  As a matter of course, I began to compress tables, in mass, during the evening in an effort to just “get everything compressed”.  Not that the gain is so good (most of the big tables are done) but in the interest of standardization.  I don’t want to have to go look and see “is it compressed?”.  Recently, however, I arrived one morning to a standard email report I have delivered which told of dozens and dozens of lines stuck in the INV.MTL_TRANSACTIONS_INTERFACE table.  For those not familiar with discrete manufacturing, this is the table where material moves and completions are processed among other things (due at least in part to Highjump, a bolt on application which allows workers to use wireless hand held terminals to do their job).  In other words, in a manufacturing environment, it’s a busy place and it needs to work correctly.

Hello, ORA-00600

The alert log doesn’t lie.  This entry corresponded to the failure times of the material transactions:

Errors in file /u01/appprod/oracle/proddb/diag/rdbms/prod/PROD/trace/PROD_ora_8556.trc  (incident=9989):
ORA-00600: internal error code, arguments: [kdsgrp1], [], [], [], [], [], [], [], [], [], [], []
Incident details in: /u01/appprod/oracle/proddb/diag/rdbms/prod/PROD/incident/incdir_9989/PROD_ora_8556_i9989.trc

The trace file revealed the RDBMS file# and block#; running that to ground confirmed that it was the INV.MTL_TRANSACTIONS_INTERFACE table.   Searching Metalink/MOS on the term KDSGRP1-1 (and changing the default search so it included bugs) , I found bug 9072813.  This was for an HP environment, but was such a similar hit that I pursued the “base bug” 8771916 which, although you couldn’t see the bug, had a patch corresponding to it.  A very, very recent patch, entitled “8771916: ORA-00600 [KDSGRP1] WHEN DOING AN UPDATE”.

Summing it all up

The first thing I did was to uncompress the MTL_TRANSACTIONS_INTERFACE table.  It went from 16 blocks back to 800, and .13 Mb back to 6.25 Mb.  That fixed the issue, but there’s more to the story.  The bug in question appears to pop when there’s massive write contention to a table (read: block).  I had just reduced the number of blocks in this table 50 fold; that’s bound to cause more contention.  In the end my fix was to also apply patch 8771916 to my production environment, knowing there could be other tables where this could occur.  If you’re running Advanced Compression, I’d urge you to at least look into the bug/patches.  If you’re running 11i and compression, I’d definitely avoid compressing interface tables.


Am I compatible with Windows 7 in the Workplace?

Filed under: Windows 7 — kkempf @ 2:14 pm

Resistance is futile


I use 64-bit Windows 7 at home, on my primary PC.  It has a lot of memory, 4 CPUs and in general does everything I could ever ask of it, and it does it well.  So I can say from the onset, I don’t have any dislike for Windows 7 (Vista was iffier).  Because of an IT initiative, all new PCs at work are being purchased with Windows 7, and I figured it was time to try it on the desktop.  I did the unfathomable, I wiped CentOS and installed 64-bit Windows 7 on my Dell D820.

There’s something really nice about having a PC which just “works”, in so many ways.   Most notably, this is in regards to hardware.  I was happily running installs of all my old favorite software… but the honeymoon is over.  Now I’m really debating, what have I done and which operating system is truly more suited for the way I work?

I have to warn in advance, this will likely be a living entry, as I find things that amaze or annoy me with Win 7.

The Terminal

I spend most of my (working) day in a terminal session.  There’s almost never not at least one open on my PC somewhere.  It’s critically important that I like it.

  • I tried Cygwin, but when I couldn’t figure out how to get an ssh session going after 5 minutes, I gave up.
  • I tried Powershell, but I was stuck in a crummy Windows command prompt.
  • I grudgingly use Putty, but it’s so GUIfied that it annoys me.
  • I’ve installed Sun Virtual Box, running Ubuntu in seamless mode on my Windows 7 desktop.  Yes, I effectively have a whole VM and kernel dedicated to running a terminal session at the moment.

The Matrix

I decided I’d just set up a matrix here, of the things each OS did right, and wrong.  Empirical evidence, if you will.

Windows 7 – The Good

  • Wireless
  • VPN
  • Office 2007 docx’s finally open!  Open Office could do this, but not on the version CentOS delivered
  • Outlook is about a million times better than Evolution, in every way from stability to features
  • Windows Clipping tool for screenshots
  • I can run my favorite editor ever, Codewright again!
  • Chrome for Windows is great.  It’s superior to IE in every way. Don’t tell Oracle, but unofficially and unsupported it runs 11i, with no tweaks on AD.I.6/ATG PF H RUP 6.  It looks like the Linux version might be out now..
  • Verizon Access Manager software for using my Blackberry as a Bluetooth tethered modem.  Wow that’s easy.

Windows 7 – The Bad

  • No native screen or page manager (WinPager works OK)
  • Always nagging me about updates

Windows 7 – The Ugly

  • Java must run 4x slower under Windows than under Linux.  I think SQL Developer takes 4 days to launch.
  • There is not a single terminal program I’ve found that I like
  • I have to run an sftp GUI to move files I download and land onto servers – it’s called Filezilla and it’s awful
  • IE 8 is the clumsiest,  slowest-launching, most bloated browser I’ve ever seen.  I believe if I had to use it to get to the maddeningly slow “My Oracle Support”, it might never come back.   And it has the nerve to default my searchbar to Bing??

CentOS – The Good

  • Oh, the simplicity of right clicking on your desktop and having a feature rich terminal session open!
  • Highlighting text and having it automatically on your clipboard, then right clicking to past.  No ctrl-c, ctrl-v or right click copy, right click paste.  This is perhaps the most frustrating loss.
  • X server automatically!
  • Security.  I can lock my terminal and pretty much nobody in the company can get into my PC.  Including IT folks unless they’re REALLY determined.  No viruses.  No 100mb McAfee antivirus updates.

CentOS – The Bad

  • Using GIMP for cropping screenshots
  • Wine is a hit and miss proposition; so, too, is Crossover Office, no matter what they claim.

CentOS – The Ugly

  • Wireless is a nightmare

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