External Article

Showplan Operator of the Week – BookMark/Key Lookup

Fabiano continues in his mission to describe the major Showplan Operators used by SQL Server's Query Optimiser. This week he meets a star, the Key Lookup, a stalwart performer, but most famous for its role in ill-performing queries where an index does not 'cover' the data required to execute the query. If you understand why, and in what circumstances, key lookups are slow, it helps greatly with optimising query performance.

Blogs

Monday Monitor Tips: Virtual Machine Usage and Cost

By

One of the things I’ve been requesting for a number of years is cost...

Advice I Like: Respect

By

“Don’t aim to have others like you; aim to have them respect you.” –...

Blue Sky Programming – The Optimism Trap

By

Many years ago, before I joined Oracle, I was working on a major modernisation...

Read the latest Blogs

Forums

SQL Art, Part 4: Happy 4th of July — A British DBA's Guide to Celebrating a War We Don't Talk About

By Terry Jago

Comments posted to this topic are about the item SQL Art, Part 4: Happy...

SQL Server Still Wins

By Steve Jones - SSC Editor

Comments posted to this topic are about the item SQL Server Still Wins

DBCC CHECKDB Limits I

By Steve Jones - SSC Editor

Comments posted to this topic are about the item DBCC CHECKDB Limits I

Visit the forum

Question of the Day

DBCC CHECKDB Limits I

When running DBCC CHECKDB on SQL Server 2025, can I include the Resource Database?

See possible answers