We have 4 tables with field types like NVARCHAR and SMALLINT and we have 4 tables in the same database with VARCHAR and SMALLINT. The all reside i the same MSSQL2008R2 database with a database collationtype LATIN_GENERAL_BIN.
If we run a simple query on the VARCHAR tables it comes with results in a few seconds. But if we run the same query on the tables with the NVARCHAR tables it takes more then 7 minutes. CPU is skyhigh during the query on NVARCHAR tables.
This is a huge performance issue and till now we don't have any idea what causes this performance flaw.
Does anyone have an idea?