Blog Aggregator - Amardeep Sidhu

So, Paul’s blog post pointing to Todd’s blog post got me thinking.
The main point Paul summarized was that duplicating data was a great way to scale, and used Todd’s reference to Flickr and how in their partition-by-user scheme, they put a comment in the commenter’s shard as well as in the commentee’s shard.
In my recent […]

Here’s a code snipped for identifying current tracefile name using SQL. Yep I know there are many such examples online, but I haven’t found any so far which also account for TRACEFILE_IDENTIFIER variable.
Luckily the value of this variable is accessible from V$PROCESS, so we can write a query which constructs us the full tracefile name, […]

Welcome the the 99th edition of Log Buffer, the weekly review of database blogs.
Since PGCon recently happened right here in Ottawa, let’s start with some posts about it, and about PostgreSQL. Josh Berkus came to the conference with his Database Soup. It sounds like he enjoyed himself: “So, that’s pgCon. It was exciting and […]

I’ve recently dug up an old presentation I did for the local Oracle User Group a number of years ago:
Yet Another Presentation On Extended Tracing
It’s slightly dated but has some useful general information on the subject of diagnosing performance issues and Extended SQL Tracing in Oracle that some may find useful, so I thought it might be worth […]

My friend asked today a question that how to identify why his Oracle 9.2 database has suddenly started generating loads more redo than usual.
So obviously I recommended him Snapper as first thing, it’s perfect for ad-hoc analysis like that! ( I know I sound biased but if you haven’t used Snapper yet, then now is […]

My friend asked today a question that how to identify why his Oracle 9.2 database has suddenly started generating loads more redo than usual.
So obviously I recommended him Snapper as first thing, it’s perfect for ad-hoc analysis like that! ( I know I sound biased but if you haven’t used Snapper yet, then now is […]

The following request appeared on the Oracle Forum a few days ago:
I have a select query
select col1,col2,col3 from table1 order by col1,col3
This table contains 4.5 million records initially and the select was returning records in less than 2 minutes .
This query has been running for the last year with out any issues, but from last […]

The following request appeared on the Oracle Forum a few days ago:
I have a select query
select col1,col2,col3 from table1 order by col1,col3
This table contains 4.5 million records initially and the select was returning records in less than 2 minutes .
This query has been running for the last year with out any issues, but from last […]

Twitter has had many outages recently. On May 17th, 2008 http://blog.twitter.com/2007/05/devils-in-details.html was posted and says:
What went wrong? We checked in code to provide more accurate pagination, to better distribute and optimize our messaging system—basically we just kept tweaking when we should have called it a day. Details are great but getting too caught up […]

In my previous post, I described the most common cause for unstable plans due to bind peeking — histograms. It is now time to move forward and take a look at another case, namely range-based predicates. Strictly speaking, the cases I’m going to describe can appear without range-based predicates as well, you just need to […]