Sql updating table
For example, changing an nchar or nvarchar column to char or varchar may cause the conversion of extended characters.
As with the SQL Profiler results of the INSERT statement this is probably due to the fact that an extra index has to be updated.
We will also break up the statements so that each operation will test referencing primary key columns as well as non-key columns that are both indexed and not indexed.
This will allow us to see how much benefit if any we get from having indexes on a column.
When the data set is small the difference in performance is almost negligible.
In my opinion if you are doing a lot of data manipulation with the temporary object after it has been created and the data set is fairly large a temporary table is the best option.