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Which is better, select from openquery or select from linked server?
When we run SELECT * FROM OPENQUERY (LINKEDSERVER, ‘SELECT * FROM DB.TABLE’) the performance flies as we would expect. At first we thought that the former method was operating locally and the latter on the linked server so obviously better performance.
Which is SQL Server instance does openquery apply to?
Applies to: SQL Server (all supported versions) Azure SQL Managed Instance. Executes the specified pass-through query on the specified linked server. This server is an OLE DB data source. OPENQUERY can be referenced in the FROM clause of a query as if it were a table name.
How is openquery referenced in a SQL query?
OPENQUERY (Transact-SQL) Executes the specified pass-through query on the specified linked server. This server is an OLE DB data source. OPENQUERY can be referenced in the FROM clause of a query as if it were a table name. OPENQUERY can also be referenced as the target table of an INSERT, UPDATE, or DELETE statement.
Is the linked Server ( Pervasive database ) failing?
After all these users are able to login, databases are accessible, reports are running and the server (ServerB) is performing well, users are able to SELECT tables from Pervasive database using linked server. But the problem is, “users are not able to execute update on pervasive database using the linked server on ServerB.
What are the performance implications of using openquery?
WHERE T1.foo = ‘bar’ SELECT * FROM OPENQUERY ( , ‘SELECT FROM MyTable WHERE foo = ”bar”’) JOIN SomeLocalTable T2 ON A limitation of OPENQUERY is that you can’t parametrise: so you need dynamic SQL to add WHERE clauses etc.
When to run select * from linkedserver.db.table?
When running a query using standard SELECT * FROM LINKEDSERVER.DB.TABLE the performance is terrible. When we run SELECT * FROM OPENQUERY (LINKEDSERVER, ‘SELECT * FROM DB.TABLE’) the performance flies as we would expect.
How to use linked server in SQL Server?
You want SQL Server to allow the linked server to do as much filtering as possible to reduce the size of the data coming over the network. For example, the 2nd case here should be more efficient. SELECT * FROM OPENQUERY ( , ‘SELECT FROM MyTable’) T1 JOIN SomeLocalTable T2 ON