Reducing update conflicts when maintaining views

摘要

Aspects of the subject matter described herein relate to reducing update conflicts when maintaining views. In aspects, a transaction in snapshot isolation may update a materialized view. Instead of being able to view the update within the transaction, the update is hidden to prevent the transaction from obtaining inconsistent data. When a transaction is not supposed to see an update to a materialized view that occurs within the transaction, additional information associated with the materialized view may indicate this. When a query of the materialized view is made within the transaction, the query engine may use the additional information to exclude data from the update in the result.

主权项

1. A computer storage medium having computer-executable instructions, which when executed perform actions, comprising:
within a transaction, making an update to a materialized view in response to a data modification that occurs after a snapshot time of the transaction, the transaction having a view of data that existed as of the snapshot time together with any changes the transaction has made to the data after the snapshot time, the update occurring before the transaction completes; and before the transaction completes, without aborting the transaction, in order to prevent the transaction from obtaining inconsistent data, excluding the update from the transaction such that a query of the materialized view within the transaction does not return the update made by the transaction, returning a result in response to the query based on data that existed before the snapshot time.