[PHOENIX-3604] Support partial drop column on immutable tables with encoded data

• Type: Task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Samarth Jain
• Created: 17/Jan/17 22:30
• Updated: 21/Jan/17 00:03

Description

We need to support dropping a column from an encoded immutable table. For v1, we should support dropping the column only from the metadata. This way users won't be able to access that column anymore through regular phoenix queries. They still would be able to access the data through hbase until we support version v2.

To support v2 (see PHOENIX-3605 ), we would need to add a "DROPPED" metadata column in SYSTEM.CATALOG. The compaction hook can then look for this attribute in the metadata row for the column and decide whether or not it should be replacing the contents with null. Our code in MetadataEndPointImpl too would then conditionally add this column to PTable so that any queries accessing the dropped column would fail.