This is the final part in a series of posts based on the content of the Query Optimizer Deep Dive presentations I have given over the last month or so at the Auckland SQL Users’ Group and the SQL Saturday events in Wellington, New Zealand and Adelaide, Australia. Links to other parts of this series: Part 1 Part 2 Part 3 Beating the Optimizer ...

This is the third part in a series of posts based on the content of the Query Optimizer Deep Dive presentations I have given over the last month or so at the Auckland SQL Users’ Group and the SQL Saturday events in Wellington, New Zealand and Adelaide, Australia. Links to other parts of this series: Part 1 Part 2 Part 4 Storage of Alternative ...

This is the second part in a series of posts based on the content of the Query Optimizer Deep Dive presentations I have given over the last month or so at the Auckland SQL Users’ Group and the SQL Saturday events in Wellington, New Zealand and Adelaide, Australia. Links to other parts of this series: Part 1 Part 3 Part 4 Cost-Based Optimization ...

This is the first in a series of posts based on the content of the Query Optimizer Deep Dive presentations I have given over the last month or so at the Auckland SQL Users’ Group and the SQL Saturday events in Wellington, New Zealand and Adelaide, Australia. Links to other parts of this series: Part 2 Part 3 Part 4 Introduction The motivation ...

There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT ...

There is much more to query tuning than reducing logical reads and adding covering nonclustered indexes.  Query tuning is not complete as soon as the query returns results quickly in the development or test environments.  In production, your query will compete for memory, CPU, locks, I/O and other resources on the server.  Today’s ...

If you look up Table Hints in Books Online, you’ll find the following statement: If a clustered index exists, INDEX(0) forces a clustered index scan and INDEX(1) forces a clustered index scan or seek. If no clustered index exists, INDEX(0) forces a table scan and INDEX(1) is interpreted as an error. The interesting thing there is ...