[PHOENIX-2565] Store data for immutable tables in single KeyValue

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.10.0
• Assignee: Thomas D'Silva
• Reporter: James R. Taylor
• Created: 05/Jan/16 06:06
• Updated: 21/Nov/17 19:39
• Resolved: 07/Mar/17 22:18

Description

Since an immutable table (i.e. declared with IMMUTABLE_ROWS=true) will never update a column value, it'd be more efficient to store all column values for a row in a single KeyValue. We could use the existing format we have for variable length arrays.

For backward compatibility, we'd need to support the current mechanism. Also, you'd no longer be allowed to transition an existing table to/from being immutable. I think the best approach would be to introduce a new IMMUTABLE keyword and use it like this:

CREATE IMMUTABLE TABLE ...

Issue Links

• is related to: PHOENIX-3295 Remove ReplaceArrayColumnWithKeyValueColumnExpressionVisitor

Sub-Tasks

• Remove ReplaceArrayColumnWithKeyValueColumnExpressionVisitor: Resolved
• Add StorageScheme table property to allow users to specify their custom storage schemes: Resolved
• Aggregate query is not blocked when projected columns are not part of group by: Resolved
• Empty array element returned with immutable encoding scheme: Resolved
• Do not issue delete markers when dropping a column from an immutable encoded table: Resolved