[IMPALA-384] In the profile the DecompressionTime is always 0ns for RCfile format

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Impala 1.0
• Fix Version/s: Impala 1.1
• Labels: profile rcfile
• Assignee: Nong Li
• Reporter: Jordan Lee
• Created: 02/Jun/13 19:51
• Updated: 20/Dec/15 00:05
• Resolved: 11/Jun/13 20:09

Description

In the query profile the DecompressionTime is always 0ns for RCfile format.
There is no variable named decompress_timer_ in hdfs-rcfile-scanner.h for measuring the decompression time.

        HDFS_SCAN_NODE (id=0):(Active: 38s514ms, % non-child: 100.00%)
          Hdfs split stats (<volume id>:<# splits>/<split lengths>): 0:10/528.46 MB 1:11/424.84 MB 2:7/169.25 MB 3:7/168.13 MB 4:12/489.22 MB 5:7/336.64 MB 
          File Formats: RC_FILE/SNAPPY_BLOCKED:54 
          ExecOption: Codegen enabled: 0 out of 108
           - AverageHdfsReadThreadConcurrency: 0.56 
             - HdfsReadThreadConcurrencyCountPercentage=0: 44.16 
             - HdfsReadThreadConcurrencyCountPercentage=1: 55.84 
             - HdfsReadThreadConcurrencyCountPercentage=2: 0.00 
             - HdfsReadThreadConcurrencyCountPercentage=3: 0.00 
             - HdfsReadThreadConcurrencyCountPercentage=4: 0.00 
             - HdfsReadThreadConcurrencyCountPercentage=5: 0.00 
             - HdfsReadThreadConcurrencyCountPercentage=6: 0.00 
             - HdfsReadThreadConcurrencyCountPercentage=7: 0.00 
             - HdfsReadThreadConcurrencyCountPercentage=8: 0.00 
           - AverageIoMgrQueueCapcity: 256.00 
           - AverageIoMgrQueueSize: 0.00 
           - AverageScannerThreadConcurrency: 0.68 
           - BytesRead: 2.07 GB
           - BytesSkipped: 0.00 
           - DecompressionTime: 0ns                 // always zero
           - MemoryUsed: 144.05 MB
           - NumDisksAccessed: 8
           - PerReadThreadRawHdfsThroughput: 109.15 MB/sec
           - RowsRead: 51.48M (51475163)
           - RowsReturned: 0
           - RowsReturnedRate: 0