Can SQL Server EXEC Statements Truly Run in Parallel?

Parallel EXEC Statements in SQL Server: Is It Feasible?

In SQL Server 2008 R2, executing multiple EXEC statements in parallel can be a perplexing challenge. Consider the following example:

EXECUTE sp_executesql N'PRINT ''1st '' + convert(varchar, getdate(), 126) WAITFOR DELAY ''000:00:10'''
EXECUTE sp_executesql N'PRINT ''2nd '' + convert(varchar, getdate(), 126)'

While the first statement delays execution for 10 seconds, the expected immediate execution of the second statement is halted until the first statement completes. This sequencing is a fundamental aspect of T-SQL's behavior.

The underlying objective is to retrieve a record, lock it temporarily, and concurrently execute other operations involving that record and its table. Executing statements asynchronously could potentially address this challenge.

BEGIN TRY
   EXEC sp_OASetProperty N'Is Network Packet Size Limited', 1
   EXEC sp_OAGetProperty N'Is Network Packet Size Limited'
END TRY

However, it's crucial to note that T-SQL is primarily intended for data manipulation, and its transactional nature, coupled with locks and commit/rollback mechanisms, makes true parallelism virtually impossible. Parallelism is more suitable for independent operations in request queues, such as in ETL processes.

Therefore, while asynchronous execution may provide a partial solution, it's essential to evaluate whether your specific scenario is truly amenable to parallelization. Data integrity and transactional semantics should be paramount considerations when exploring such approaches.

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