SQL Server简单的WHERE子句极其慢

Question

My SQL Server query is something like

Select * 
from mytable 
where mycolum = X

The table only has about 8000 records, and this query used to run extremely fast.

Now all of a sudden it's running super slow. Any thoughts? Here's what I've tried

• Updating the statistics for that table
• Shrinking the database
• Updating stats for the entire database via sp_updatestats
• Restarting the db server

None of these are working.

Any ideas or things I could try?

Answer 1

You should create an index for the column. If you are using a production DB that needs to remain active during the building of the index then you want to use ONLINE = ON in my sample below.

CREATE INDEX mytable_indx1 ON dbo.mytable (mycolum) WITH (ONLINE = ON);