2
votes
1answer
116 views

Is there a negative effect if I place an index on every column in a wide table?

We have a wide dataset that isn't very tall (say 250K rows, 90 columns). We will be providing users with an interface that allows them to generate arbitrary queries against this dataset. They can ...
5
votes
1answer
344 views

Optimize where clause using dates

I'm trying to optimize several queries that all use a similar pattern on one of the WHERE clauses: AND (DATEADD(DAY , ISNULL(a.[due_days], 30) + 30 , [dbo].[CalcDate]([type], ...
0
votes
2answers
400 views

How can I speed up this query on table with 65 million records

select hash_id, hash_value, substring(T.cri, 1, 7), substring(T.cri, 9, D2.Pos-9), substring(T.cri, D2.Pos + 1, D3.Pos - D2.Pos - 1), ...
2
votes
1answer
125 views

Optimizing query on a partitioned table

Tried to find an answer for this, but couldn't. So bear with me and apologies if this has been answered elsewhere. It may be just me not being able to find it. Here's the setup: SQL 2008 R2 EE. Table ...
1
vote
1answer
274 views

Optimising a query of an SSRS dataset

Consider the query given below: SELECT * FROM ((SELECT c.cust_id , c.username , REPLACE(qs.seg_type_ref_key_02, 'N/A', 'Non Vip') casino_group, ...
9
votes
5answers
1k views

Force sql server to run query conditions as written?

Im using Sql server 2008 R2 And I have this pseudo query (SP) : select ... from ... WHERE @LinkMode IS NULL AND (myColumn IN (...very long time exeted query...)) ... ... The ...
5
votes
2answers
917 views

Bulk Data Loading and Transaction Log

im currently working on a project which bulk import data from flat files(csv) about 18 differents files each linking to a specific table through some store procedure. I followed the steps as advised ...
7
votes
2answers
4k views

Why is this query not using my nonclustered index, and how can I make it?

As follow up to this question about increasing query performance, I'd like to know if there is a way to make my index used by default. This query runs in about 2.5 seconds: SELECT TOP 1000 * FROM ...
3
votes
1answer
108 views

can sql generate a good plan for this procedure?

I have read that procs that do not always do the same thing per se, will not always have a good plan generated. That is (correct me if I'm wrong), if I have a proc that if the day is even it reads ...
5
votes
2answers
3k views

REBUILD - Clustered Index, TABLE, or both?

I'm having trouble finding a definitive resource on this anywhere, so hopefully a guru can give me an answer here. I have a very large table that we had to add a column to. The clustered index is ...
10
votes
2answers
785 views

Optimization: Moving variable declarations to the top of your procedure

While working on optimizing some stored procedures, I sat down with the DBA and went through some sprocs with high blocking and/or high read/write activity. One thing the DBA mentioned was I should ...
4
votes
4answers
895 views

Where to look for a bottleneck after elimitating CPU, memory, and disk

I have a database job that runs each night to create a warehouse table. Using my new database server and SAN I have gotten the process down from 4 1/2 hours to 35 minutes. I have optimized it to run ...