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Row_number() slow on large datasets

Thread by: Steph2004, May 7, 2009, 1 replies, in forum: SQL Server 2005 T-SQL Performance Tuning

Hi, I have this query going like this: select * from ( select id, row_number()over(partition by fk_tbl_visits_id order by id desc) as rn...

Query is slow because of TOP and Order By Count(*)

Thread by: Steph2004, Sep 28, 2008, 1 replies, in forum: SQL Server 2005 General Developer Questions

Hi, I have a log table that saves web visits. And I have this query which is pretty slow : select top 500 count(1) as nbCount, currentPage as...

What's the best way to create à clustered index?

Thread by: Steph2004, Aug 20, 2008, 1 replies, in forum: SQL Server 2005 Performance Tuning for DBAs

Hi, I keep wondering what's the best way to create a clustered index. I tried many ways. Some make the query fast even though I think it could be...

Getting unique ids affected by a group by clause

Thread by: Steph2004, Jul 31, 2008, 1 replies, in forum: SQL Server 2005 General Developer Questions

Hi, Let's say I have a customer table and an order table. In the order table, I have the customer name. So if I want to select the orders grouped by...

Optimizing index for select count(distinct)

Thread by: Steph2004, Jun 12, 2008, 6 replies, in forum: SQL Server 2005 T-SQL Performance Tuning

Hi, I have a table logging our website activity with about 60 M of rows. One user has for itself more than 1 M rows. When I do a count(distinct), it...

How to segment data like Google Analytics

Thread by: Steph2004, Apr 8, 2008, 4 replies, in forum: SQL Server 2005 General Developer Questions

Hi, I'm trying to build my own web stats tool like Google Analytics. And like them, I'd like to implement a drill down function to segment data on...

Slow clustered index seek

Thread by: Steph2004, Jan 22, 2008, 9 replies, in forum: SQL Server 2005 Performance Tuning for DBAs

Hi, I have a table with 100 M+ rows. As the table grows, the select queries are getting slower. In the execution plan, everything looks fine since...