[PHOENIX-2179] Trace output contains extremely large number of readBlock rows

• Type: Sub-task
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Labels: tracing
• Assignee: Unassigned
• Reporter: Mujtaba Chohan
• Created: 13/Aug/15 00:23
• Updated: 20/Feb/16 22:28

Description

As an example, trace over a 10M row table using count * query produces over 250K rows for HFileReaderV2.readBlock.

select count(*), description from SYSTEM.TRACING_STATS WHERE TRACE_ID=X group by description;
+------------------------------------------+------------------------------------------+
|                 COUNT(1)                 |               DESCRIPTION                |
+------------------------------------------+------------------------------------------+
| 3                                        | ClientService.Scan                       |
| 253879                                   | HFileReaderV2.readBlock                  |
| 1                                        | Scanner opened on server                 |
+------------------------------------------+------------------------------------------+