[DRILL-2719] Behavior of ValueVector#getBuffers(clear) is inconsistent across VV types

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.0
• Fix Version/s: 0.9.0
• Component/s: Execution - Data Types
• Assignee: Hanifi Gunes
• Reporter: Hanifi Gunes
• Created: 08/Apr/15 06:58
• Updated: 16/Apr/15 21:16
• Resolved: 16/Apr/15 21:16

Description

The major cause of inconsistency here is that reference count does not change upon a call to BaseDataVV#getBuffers. However, it does change when the method is invoked on a composite vector type. See for instance VariableLengthVV[1] or a NullableVV[2].

The proposal is to make this behavior consistent first and later we can consider separating out the logic that clears a vector from the logic that returns underlying buffers.

[1]: https://github.com/apache/drill/blob/master/exec/java-exec/src/main/codegen/templates/VariableLengthVectors.java#L151
[2]: https://github.com/apache/drill/blob/master/exec/java-exec/src/main/codegen/templates/NullableValueVectors.java#L82

Issue Links

• is depended upon by: DRILL-2611 Value vectors report invalid value count
• is related to: DRILL-1942 Improve off-heap memory usage tracking
• links to: GitHub
• links to: ReviewBoard