Friday, June 11, 2010

SQL Profiler EventClass & EventSubClass Column Descriptions

http://blogs.msdn.com/b/danhardan/archive/2008/09/10/sql-profiler-eventclass-eventsubclass-column-descriptions.aspx

Algebrizer

Generally In SQL Server, When You submit a query the following activities taken place Internally:

1. Parser

2. Algebrizer (Normalizer)

3. Optimizer -

In SQL Server upto 2000, The term is 'Normalizer', But in 2005/2008 is called as 'Algebrizer' not 'Normalizer'( The tern replaced as 'Algebrizer') - There is some internal changes are there between the two as follows..

A) The 'Normalizer' will not maintain any Optimization History, It will maintain only the replaced final value alone.

b) But, The 'Algebrizer' will maintain Optimization History.

We can view the optimization history by

SELECT * FROM SYS.DM_EXEC_QUERY_OPTIMIZER_INFO -

The DMV will have three columns Counter, Occurrence & Value.

Algebrizer is a new component in SQL server 2005, which replaces the Normalizer in SQL Server 2000. It takes the output of Parser and binds. Binding and Algebrizer are both same.

Joins

Hash joins parallelize and scale better than any other join and are great at minimizing response times for data warehouse queries.