SQL Server linked server performance

Question

I am using SQL Server 2008 Enterprise. And I am using Linked Server technologies to link another SQL Server 2008 Enterprise instance from another server. I write TSQL to manipul

Answer 1

@George2,

Sam Saffron is correct in this case. When a join is performed locally then SQL Server uses indexes to perform a join and then does lookups for the columns not included into an index definition.

With linked server to do a join all table needs to be transferred from a remote server first, then join is performed. This is a bottle neck. If you can pre-filter all remoted tables before joining them to local tables it will considerably improve performance (e.g. select into #temp tables with good filter to reduce number of rows), then if you need to perform multiple operations against that table you are better off creating an index right away.