tencent cloud

mysql> set enable_profile=true; 

Query:
  Summary:
    Query ID: 9664061c57e84404-85ae111b8ba7e83a
    Start Time: 2020-05-02 10:34:57
    End Time: 2020-05-02 10:35:08
    Total: 10s323ms
    Query Type: Query
    Query State: EOF
    Doris Version: trunk
    User: root
    Default Db: default_cluster:test
    Sql Statement: select max(Bid_Price) from quotes group by Symbol

    Fragment 0:
      Instance 9664061c57e84404-85ae111b8ba7e83d (host=TNetworkAddress(hostname:192.168.0.1, port:9060)):(Active: 10s270ms, % non-child: 0.14%)
         - MemoryLimit: 2.00 GB
         - BytesReceived: 168.08 KB
         - PeakUsedReservation: 0.00 
         - SendersBlockedTimer: 0ns
         - DeserializeRowBatchTimer: 501.975us
         - PeakMemoryUsage: 577.04 KB
         - RowsProduced: 8.322K (8322)
        EXCHANGE_NODE (id=4):(Active: 10s256ms, % non-child: 99.35%)
           - ConvertRowBatchTime: 180.171us
           - PeakMemoryUsage: 0.00 
           - RowsReturned: 8.322K (8322)
           - MemoryUsed: 0.00 
           - RowsReturnedRate: 811

OLAP_SCAN_NODE (id=0):(Active: 1.2ms, % non-child: 0.00%)
  - BytesRead: 265.00 B                 # The amount of data that has been read from the data file. If ten 32-bit integers are read, then the data amount is 10 x 4B = 40 Bytes. This number only represents the memory size when the data is fully expanded and does not represent the actual IO size. 
  - NumDiskAccess: 1                    # Number of disks that the ScanNode node has involved.
  - NumScanners: 20                     # Number of Scanners that the ScanNode has generated.
  - PeakMemoryUsage: 0.00               # The peak memory usage during querying, currently not used
  - RowsRead: 7                         # The number of rows returned from the Storage engine to the Scanner, excluding the rows filtered by the Scanner.
  - RowsReturned: 7                     # The number of rows returned by the ScanNode to the upper node.
  - RowsReturnedRate: 6.979K /sec       # RowsReturned/ActiveTime
  - TabletCount : 20                    # The number of Tablets involved in this ScanNode.
  - TotalReadThroughput: 74.70 KB/sec   # BytesRead divided by the total running time of this node (from Open to Close). For IO-restricted queries, this value approaches the total throughput of the disk.
  - ScannerBatchWaitTime: 426.886us     # The time taken by the transfer thread to wait for the scanner thread to return rowbatch.
  - ScannerWorkerWaitTime: 17.745us     # The time taken by the scanner thread to wait for available worker threads in the Thread Pool.
  OlapScanner:
    - BlockConvertTime: 8.941us         # The time taken to convert the vectorized Block to the row structure's RowBlock. In V1, the vectorized Block is VectorizedRowBatch, and in V2, it's RowBlockV2.
    - BlockFetchTime: 468.974us         # The time taken by the Rowset Reader to obtain the Block.
    - ReaderInitTime: 5.475ms           # The time taken by the OlapScanner to initialize the Reader. In V1, this includes the time taken to assemble MergeHeap. In V2, it includes the time to generate each level Iterator and read the first set of Blocks.
    - RowsDelFiltered: 0                # The number of rows filtered based on the Delete information in Tablet, as well as the number of rows marked for deletion filtered under the unique key model.
    - RowsPushedCondFiltered: 0         # The number of rows filtered based on the predicates pushed down, such as the conditions passed from BuildTable to ProbeTable in Join computation. This number is not accurate as the filtering will stop if it yields poor results.
    - ScanTime: 39.24us                 # The time returned by the ScanNode to the upper node.
    - ShowHintsTime_V1: 0ns             # Meaningless in V2. In V1, it reads part of the data to split the ScanRange.
    SegmentIterator:
      - BitmapIndexFilterTimer: 779ns   # The time taken to filter data using bitmap index.
      - BlockLoadTime: 415.925us        # The time taken by the SegmentReader(V1) or SegmentIterator(V2) to access the block.
      - BlockSeekCount: 12              # The number of performed block seek operations  when reading the Segment.
      - BlockSeekTime: 222.556us        # The time taken to perform a block seek operation when reading the Segment.
      - BlocksLoad: 6                   # The number of Blocks read
      - CachedPagesNum: 30              # Only in V2, when PageCache is enabled, the number of Pages that hit the Cache.
      - CompressedBytesRead: 0.00       # In V1, the size of the data read from the file before decompression. In V2, the size before compression of the Pages that were read and did not hit the PageCache.
      - DecompressorTimer: 0ns          # The time taken to decompress the data.
      - IOTimer: 0ns                    # The IO time of actual data reading from the operating system.
      - IndexLoadTime_V1: 0ns           # Only in V1, the time taken to read the Index Stream.
      - NumSegmentFiltered: 0           # The number of Segments completely filtered out through column statistics and query conditions when generating the Segment Iterator.
      - NumSegmentTotal: 6              # The total number of Segments involved in the query.
      - RawRowsRead: 7                  # The number of raw rows read in the Storage engine. See below for details.
      - RowsBitmapIndexFiltered: 0      # Only in V2, the number of rows filtered out using the Bitmap index.
      - RowsBloomFilterFiltered: 0      # Only in V2, the number of rows filtered out using the BloomFilter index.
      - RowsKeyRangeFiltered: 0         # Only in V2, the number of rows filtered out using the SortkeyIndex index.
      - RowsStatsFiltered: 0            # In V2, the number of rows filtered out using the ZoneMap index, includes deletion conditions. In V1, it also includes the number of rows filtered out using the BloomFilter.
      - RowsConditionsFiltered: 0       # Only in V2, the number of rows filtered out using various column indexes.
      - RowsVectorPredFiltered: 0       # The number of rows filtered by the vectorized conditional filter operation.
      - TotalPagesNum: 30               # Only in V2, the total number of Pages read.
      - UncompressedBytesRead: 0.00     # In V1, the size of the data file after decompression (If the file does not need to be decompressed, the file size is counted directly). In V2, only the sizes of Pages that did not hit the PageCache after decompression are counted (If a Page does not need to be decompressed, its size is counted directly)
      - VectorPredEvalTime: 0ns         # The time taken for a vectorized conditional filter operation.