Project

General

Profile

Actions

Feature #4385

closed

Unify empty arrays and NULLs

Added by Pavel Kácha over 5 years ago. Updated over 5 years ago.

Status:
Rejected
Priority:
Normal
Assignee:
Category:
Design
Target version:
Start date:
10/19/2018
Due date:
% Done:

0%

Estimated time:
To be discussed:

Description

Arrays in metadata table are not consistent in usage of NULLs and empty arrays. We might benefit from unification (as we don't differentiate nonexistent and empty arrays). Question is is which is "better":

  • Empty array may have space overhead, however the column then does not need to be NULL. Also, some queries might be simpler with no need for NULL special case.
  • NULL value may have overhead for the whole column, on the other side, seems like NULLs are stored as bitmap per row, so additional bit if there are already another NULL columns is negligible. How about query specialcasing?

Partially stems from #4348.


Related issues

Related to Mentat - Feature #4348: Better support for sparse columnsClosedRadko Krkoš10/05/2018

Actions
Actions

Also available in: Atom PDF