sql server data annotations nvarchar required inde

Sql server data annotations nvarchar required inde how to#

For deeper details about these types, check Working with different SQL Server indexes types.Īfter creating the index, we need also to monitor that index usage to make sure that it still efficient and useful for us.These indexes include the Unique index, Filtered index, Spatial Index, XML index, Clomunstore index, Full-Text index, and Hash index. SQL Server provides us also with other special purposes SQL indexes, derived from the clustered and non-clustered types, that can help in improving the performance of the T-SQL queries. For more information about the non-clustered index, check Designing effective SQL Server non-clustered indexes.The second main type of SQL Server indexes is the non-clustered index in which the leaf nodes of that index stores only the index key values with a pointer to the storage location of that rows in the main heap table or the clustered index, with the ability to create up to 99 non-clustered indexes per each table. For more information about the clustered index, check Designing effective SQL Server clustered indexes.The clustered index existence covert the table from an unsorted heap table to a sorted clustered table. The clustered index that is used to store the whole table data based on a select index key consists of one or multiple columns, with the ability to create only one clustered index per each table. SQL Server provides us with two main types of indexes. Tracing and tuning queries using SQL Server indexes.SQL Server Index Structure and Concepts.

Sql server data annotations nvarchar required inde how to#

In other words, the existence of that index will save time and resources.įor more information about the SQL index structure, different operations that can be performed on an index and how to take advantage of the index in tuning the T-SQL queries performance, check the following articles: It works similar to the book’s index that helps in identifying the location of each unique word, by providing the page where you can find that word, rather than spending the whole weekdays reading the book to check a specific subject or identifying that word. It helps in speeding up the queries by providing swift access to the requested data, called index seek operation, instead of scanning the whole table to retrieve a few records. SQL index is considered as one of the most important factors in the SQL Server performance tuning field. Note: To learn more about SQL Server indexes, please read SQL Server Indexes: Key Requirements, Performance Impacts and Considerations article. Before going through the index design procedure, let us revise the SQL Server index concept. In this article, we will discuss the most important points that we should consider when designing an optimal SQL index.