Wednesday, January 18, 2012

AWR snapshot creation hangs

Oracle 10g R1

I encountered a problem with the AWR snapshot in which the creation would hang. This phenomenon is due to an Oracle bug #7284976. The Metalink bug report indicates that it is applicable to DB version Enterprise Edition and doesn't list any other affected versions, however I seem to be encountering this on DB version Standard Edition running on IBM AIX platform.

Tuesday, January 17, 2012

Great tools for identifying a font

I recently wanted to use a font I has seen used on a business card. I spent hours trawling through massive lists of fonts when it occurred to me that there are probably tools on the web that can help me find it faster.

A quick google search provided many really good resources. Two stood out immediately:
  • If you are lucky enough to have an image of the text, then WhatTheFont is without a doubt the place you want to be. Simply upload an image of the font and the site will provide you with a list of closest matches.
  • In my case, I had a business card on my desk and didn't feel like hassling with the scanner. So my choice was Identifont. The Identifont engine asks a number of questions about the look of the font and provides a list of matching fonts based on your response. A great feature is that it provides an updated list of fonts after each question.

Thursday, January 12, 2012

Workaround for ORA-24347: Warning of a NULL column in an aggregate function

Oracle 10g R2
ORA-24347: Warning of a NULL column in anaggregate function

I encountered this error while using DBMS_XMLGEN to generate someXML output. And if you're reading this, it's most likely because you encountering the same problem.

Well, it turns out there is an Oracle bug (#5911073,consult metalink) that throws this error when an aggregate function (such as SUM, COUNT or AVG) receives a NULL input value and is used in conjunction with DBMS_XMLGEN.

The following script demonstrates the problem: