Overloaded Database - Batch Updates vs Atomic/Single Updates We have on overloaded database which is now receiving failed transactions consequently. The proposed solution is to create a 2nd database that taskes all the (ecommerce) transactions initially and processes &amp; persists them.  Then, eventually, the current/old database will be updated. That's the simple overview. 

The question I have is - when I do the batch update from newDBServer -> OldDBServer every x minutes, won't it slow operations down on the old server during that update (assuming this isn't done overnight, etc...)?  

The server is under a heavy load, so that's why I'm not certain it will really help minus the time in between updates. Is there a better way to do this?
I agree with @gbn, can you share more details about what constitutes "load". 

First take a look at your server level wait types to get a feel for where your resource crunch points are. 

Also identify your poorest performing queries and those that are most frequently executed. These are where you should target your performance tuning efforts.

To get you started quickly, grab a copy of Glenn Berry's SQL Server Diagnostic Queries which contain a number of useful scripts that you can use.