Reducing registration overhead

alexstyler

Hi, I'm using the toolkit in a new project to compare a database with it's snapshot (a database identical in structure when taken).

I know that the databases are identical and I'm only interested in data differences. Is there any way to reduce the overhead associated with RegisterForDataCompare if I know the structure is identical and I'm only interested in the data?

I attempted enabling almost every ignore option possible, but a trace shows that you still query the server for the same information, presumably ignoring it on your end instead of not retrieving it to begin with.

Thanks,
Alex

Brian Donahue

Hi Alex,

I can't get a Data Compare to work without using the RegisterForDataCompare call first. Loading a snapshot saved with SQL Compare and comparing it to a database registered for data compare always results in a null-reference exception, so I'd have to say that using the RegisterForDataCompare method is mandatory.

alexstyler

Let me clarify,

I'm comparing a database with a "database snapshot" created by SQLServer 2005. These snapshots act as exact, read-only replicas of the original database when the snapshot was taken. They are stored as diffs of the original database, so the initial act of creating a snapshot is almost instantaneous.

I'm taking a snapshot, applying some modifications, then using DataCompare to verify the database behaves as expected. That is, certain operations yield the same effects on a database time after time.

My question was: are there any ways to reduce the overhead of RegisterForDataCompare? It takes some options, which don't seem to affect its number of roundtrips to the database.

In my situation, I only care about data, no triggers, schema, or functional comparisons; I know the structures of the databases will be identical.

I've done some more testing and indeed I cannot reduce the overhead. I moved towards registering once and handling the effects myself.

Thanks for your effort and response. Perhaps in a future version of the toolkit you may consider adding more options to the registration and only query the databases for the data you need.

Brian Donahue

Hi Alex,

There is a bit of ambiguous terminology going on here, so I apologise for any confusion. SQL Compare can save a structured file representation of your database schema, which is also called a snapshot. My thinking was that you could get around having to use RegisterForDataCompare by loading the snapshot file from disk using the database.loadfromdisk method. What I found was that this doesn't work for DataCompare.Engine.

I don't know of any way to speed up RegisterForDataCompare.