Concurrency

Do single commands (or stored procedures) execute concurrently, or they are executed one by one. How do you perform a lock during the execution of a command (or stored procedure).

Single commands are 'implied' transactions, that is the command executes completely, or nothing is done.

For multiple commands, where there is a need to make sure the several statements execute in a 'all or nothing' scenario, use TRANSACTIONS.

Refer to Books Online, Topic: Transactions

|||

Other good topics in the BOL are "Isolation mode" and locking hints.

Jens K. Suessmeyer.

http://www.sqlserver2005.de