I'm new to sql server 2005 and was reviewing the execution plan on one of my queries.
I have a query that selects about 62,000 rows from a table of about 20 million
I see there is a index seek indicated but further down the execution plan I see that a large percent is being assigned to a RID LOOKUP on the same table.
Should I be concerned with this and if so, what would you recommend I do to correct it?
Indexes are like sorted miniature tables. They contain the indexed columns, any included columns, and lastly the primary key (or the internal row ID if a primary key does not exist).
If you see a lot of time lost to RID lookups, you have two options to correct it:
1) Change the clustered index to cover the column(s) that's being seeked upon. If the table has a primary key, the clustered index is created on it by default.
2) Modify your index to "include" the other columns needed by the query. If you're using SELECT *, change the * to a column list.
-Ryan / Kardax
