Type: New Feature
Affects Version/s: None
Fix Version/s: 4.11.0
HBase support scanning over snapshots, with a SnapshotScanner that accesses the region directly in HDFS. We should make sure that Phoenix can support that.
Not sure how we'd want to decide when to run a query over a snapshot. Some ideas:
- if there's an SCN set (i.e. the query is running at a point in time in the past)
- if the memstore is empty
- if the query is being run at a timestamp earlier than any memstore data
- as a config option on the table
- as a query hint
- based on some kind of optimizer rule (i.e. based on estimated # of bytes that will be scanned)
Phoenix typically runs a query at the timestamp at which it was compiled. Any data committed after this time should not be seen while a query is running.