,NET SQLDatareader isolated read

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I have a SQL database which stores accounts with credits (about 200.000 records), and a separate table which stores the transactions (about 20.000.000).

Whenever a transaction is added to the database the credits are updated.

What I need to do is update client programs (using a webservice) to store the credits locally, and whenever new transactions are added to the server they are sent to the clients as well (using timestamps for the delta). My main problem is creating the first data set for the client. I need to supply the list of all accounts and the last timestamp on the transaction table.

This would mean I have to create this list and the last timestamp within a snapshot, because any updates during creating this list would mean a mismatch in credits total and last transaction timestamp.

I've researched the ALLOW_SNAPSHOT_ISOLATION setting and using Snapshot isolation on the sqlcommand transaction, but from what I've read this will induce a significant performance penalty. Is this true, and can this problem be solved using other means ?

asked 5 secs ago

user3575631

1