How column COLLATION can affect SQL Server query performance. Problem. Most DBAs, myself included, install SQL Server with the default server collation SQL. This tip will look at the performance impacts of querying data with this setting as it compares to querying columns with the collation set to SQL. One of the varchar columns will have the collation set to SQL.
For installation or setup questions, refer to the Setup Forum. And I guess Microsoft made the US English default to be a SQL collation because that's the what SQL Setup did in prior. Microsoft probably chose to make the SQL
2005 on to a Windows 7 machine it installs properly but the collation installed is sql. 2005 collation issue during installation. Help All my USER DB have been created using the following collationL SQL. Hello, I hope someone can help, I am trying to install a collation of SQL. I understand that the OS regional settings have an influence on this an at setup I choose the SQL.
We'll also create an index on both columns. If we don't have an index on the column it would have to do a table scan in both cases and we would not see any difference in performance. Also, in the real world, any heavily queried column would be indexed so it makes sense to do the same for our performance test. Below is the query to create this table and indexes as well the T- SQL to load some random string data into the table. CREATE TABLE . In this scenario, for the query on the column defined with SQL.
Here are examples of each query. E'. select * from test where UPPER(col. NPE'. select * from test where col. COLLATE SQL. The first query uses an index seek which will most likely execute much faster using fewer resources. We can confirm the performance by looking at the SQL Trace results. From the chart below we can see that the first query outperforms the other two in every category.
CPUReads. Writes. Duration. Rows. CI Query - CI Column. CI Query - CS Column with Function. CI Query - CS Column with Collation. Test Scenario 2 - Case sensitive query. Now let's take a look at the results when performing a case sensitive search on each of our columns. In this scenario the query of the SQL.
Here are examples of each query. COLLATE SQL. The later query uses an index seek which will most likely execute much faster using fewer resources. We'll again confirm the performance by looking at the SQL Trace results. From the chart below we can see that the second query which uses an index seek outperforms the other query in every category as was the case in our previous scenario. CPUReads. Writes. Duration. Rows. CS Query - CI Column with Collation.
CS Query - CS Column. Summary. These simple test scenarios above illustrate how we need to be aware of how our data is being queried by the application.
Cannot resolve the collation conflict between 'SQL.
Once we know this we can then design the schema correctly so we can avoid any of these unnecessary index scans. Next Steps. Last Update: 4/2. About the author. Ben Snaidero has been a SQL Server and Oracle DBA for over 1.