[FLINK-629] Add support for null values to the java api

• Type: Improvement
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: pre-apache
• Labels: github-import
• Assignee: Gyula Fora
• Reporter: Stephan Ewen
• Created: 09/Jun/14 12:38
• Updated: 28/Feb/19 14:29
• Resolved: 06/Sep/14 23:06

Description

Currently, many runtime operations fail when encountering a null value. Tuple serialization should allow null fields.

I suggest to add a method to the tuples called `getFieldNotNull()` which throws a meaningful exception when the accessed field is null. That way, we simplify the logic of operators that should not dead with null fields, like key grouping or aggregations.

Even though SQL allows grouping and aggregating of null values, I suggest to exclude this from the java api, because the SQL semantics of aggregating null fields are messy.

---------------- Imported from GitHub ----------------
Url: https://github.com/stratosphere/stratosphere/issues/629
Created by: StephanEwen
Labels: enhancement, java api,
Milestone: Release 0.5.1
Created at: Wed Mar 26 00:27:49 CET 2014
State: open

Issue Links

• is duplicated by: FLINK-1033 Serializers Cannot Handle Null Values
• relates to: FLINK-1446 Make KryoSerializer.createInstance() return new instances instead of null