[HBASE-5523] Fix Delete Timerange logic for KEEP_DELETED_CELLS

• Type: Sub-task
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.94.0, 0.95.0
• Component/s: regionserver
• Hadoop Flags: Reviewed
• Assignee: Lars Hofhansl
• Reporter: Lars Hofhansl
• Created: 05/Mar/12 22:43
• Updated: 26/Feb/13 08:12
• Resolved: 06/Mar/12 06:22

Description

A Delete at time T marks a Put at time T as deleted.
In parent I invented special logic that insert a virtual millisecond into the tr if the encountered KV is a delete marker.
This was so that there is a way to specify a timerange that would allow to see the put but not the delete:

if (kv.isDelete()) {
  if (!keepDeletedCells) {
    // first ignore delete markers if the scanner can do so, and the
    // range does not include the marker
    boolean includeDeleteMarker = seePastDeleteMarkers ?
    // +1, to allow a range between a delete and put of same TS
    tr.withinTimeRange(timestamp+1) :
    tr.withinOrAfterTimeRange(timestamp);

Discussed this today with a coworker and he convinced me that this is very confusing and also not needed.
When we have a Delete and Put at the same time T, there is not timerange that can include the Put but not the Delete.

So I will change the code to this (and fix the tests):

if (kv.isDelete()) {
  if (!keepDeletedCells) {
    // first ignore delete markers if the scanner can do so, and the
    // range does not include the marker
    boolean includeDeleteMarker = seePastDeleteMarkers ?
    tr.withinTimeRange(timestamp) :
    tr.withinOrAfterTimeRange(timestamp);

It's easier to understand, and does not lead to strange scenarios when the TS is used as a controlled counter.

Needs to be done before 0.94 goes out.