[Feature Request]: Datastore Beam connector to support readTime #22051
Description
What would you like to happen?
Datastore allows reads to specify a read_time. Without read_time, a read targets the most up to date state of the database. In a Beam workload with many reads issued at different times, this can mean the entire dataset read from Datastore is not necessarily a consistent copy of the database if there are writings also happening. We should allow the Datastore Beam connector to be configured with a read_time, and issue all the reads with that read_time, this will allow us to be able to read consistently from Datastore in a Beam workload.
Issue Priority
Priority: 2
Issue Component
Component: io-java-gcp