[FLINK-573] Clean-up MapOperators in optimizer

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Done
• Fix Version/s: 1.0.0
• Labels: github-import
• Assignee: Unassigned
• Reporter: GitHub Import
• Created: 09/Jun/14 12:32
• Updated: 30/Nov/15 19:48
• Resolved: 30/Nov/15 19:48

Description

This issue continues a discussion started by @aljoscha in PR (#544 | FLINK-544).

MapNode is responsible for PlainMapOperatorBase and not for
MapOperatorBase, but this is a mess right now.

Maybe we should think about cleaning the situation a bit. CollectorMap is the same as FlatMap, only the function in the interface is called map instead of flatMap. I know that this is because of historic reasons but it is still a mess because we handle all three types through the layers. For example, some code in PactCompiler looks like this:

```java
else if (c instanceof MapOperatorBase) {
n = new CollectorMapNode((MapOperatorBase<?>) c);
}
else if (c instanceof PlainMapOperatorBase) {
n = new MapNode((PlainMapOperatorBase<?>) c);
}
else if (c instanceof FlatMapOperatorBase) {
n = new FlatMapNode((FlatMapOperatorBase<?>) c);
}
```

---------------- Imported from GitHub ----------------
Url: https://github.com/stratosphere/stratosphere/issues/573
Created by: fhueske
Labels: enhancement, optimizer,
Created at: Fri Mar 14 02:11:22 CET 2014
State: open