I have two tables with same structure I need to copy over all tables from table A to table B, the problem is that some records from table A already exist in table B so that made the Import Fail.
So I made a query to do the import (Also using the build in Import tool) like that
SELECT * from TransactionEntryN WHERE TransactionEntryN.TransactionEntryID NOT IN (select TransactionEntryID FROM TransactionEntry)
The problem is that this operation takes 13 min. to copy just 50K records and I have 16 Million records there, it would take me a week to finish that...
Is there any faster way to do it?
btw the primary key TransactionEntryID is a uniqueidentifier that may slow it down? (I can't change it I'm just wondering if that the issue.