SQL Indexing and SQL Performance Part 4: Design Considerations

2016-10-19T13:11:16+02:00Wednesday, 12 January, 2011|Categories: Technical|Tags: , , , , , , , , , |

In the previous part of the blog post series you’ve seen that the query optimizer examines query predicates in order to analyze statistics for useful indexes in the execution plan decision process. Since indexes are quite important to the query optimization process, the first design tip is to consider WHERE, JOIN, MERGE, ORDER BY and [...]

SQL Indexing and SQL Performance Part 3: Queries, indexes and the query optimizer

2016-10-19T13:11:17+02:00Monday, 20 December, 2010|Categories: Technical|Tags: , , , , , , , , , |

Which columns should you choose for indexing? To decide on the columns of an index you have to consider the most frequent queries running against your tables. You have to examine the WHERE and JOIN clauses (ORDER BY and GROUP BY also benefit from indexes), since SQL query optimizer will try to find the best [...]

SQL Indexing and SQL Performance Part 2: Clustered and Non-Clustered

2015-06-09T11:34:07+02:00Tuesday, 30 November, 2010|Categories: Technical|Tags: , , , , , , , , , |

So, why do you need to index your tables? Because without an index the SQL server has to scan the entire table to return the requested data. It is like the index page in a book. You check within the index for the keyword you want to learn about. From that point forward, you jump directly to [...]