Updating a view mssql
These are not considered ‘user created’ even though our user query was the cause of them being auto-generated.(“User created” means someone ran a CREATE STATISTICS command.) SQL Server can now use the statistic on Gender and the statistic on First Name Id for future queries that run. First Name By Year table has a clustered primary key, and here is the statistic that was created along with that index: If columns are important enough to index, SQL Server assumes that it’s also important to estimate how many rows would be returned by that index when you query it.With default database settings, the SQL Server optimizer looks at how many changes have occurred for a given column statistic as part of query optimization.If it looks like a significant amount of rows in the column have changed, SQL Server updates the statistic, then optimizes the query.The SQL Server query optimizer uses statistics to estimate how many rows will be returned by parts of your query. By default, the SQL Server optimizer will see that no statistics exists, and wait while two column statistics are created on the First Name Id and Gender columns.Statistics are small, and are created super fast– my query isn’t measurably any faster when I run it a second time.In these type of situations it is ideal to use a Update Cursor, than using the default read only one.
(I think we know which team really felt some pain and wanted this trace flag to exist, because the trace flag was announced on their blog! So if you’re using SQL Server 2016, you don’t need to decide.A view is stored as a SELECT statement in the database.DML operations on a view like INSERT, UPDATE, DELETE affects the data in the original table upon which the view is based.If you’re managing lots of SQL Server instances and want ultimate customization, there is a free version of Minion Reindex. The answers to both of these questions impact what it does to GROUP those rows and SUM the Name Count column.
Statistics are small, lightweight objects that describe the distribution of data in a SQL Server table. First Name By Year and you run this query: SQL Server needs to estimate how many rows will come back for First Name Id=74846. Statistics are lightweight little pieces of information that SQL Server keeps on tables and indexes to help the optimizer do a good job. First Name By Year table was freshly created when we ran our query, it would have no column statistics.I’ve been asked a lot of questions about updating statistics in SQL Server over the years. Here’s a rundown of all the practical questions that I tend to get about how to maintain these in SQL Server.