Hi, all I submitted a pr[1] to support [IOTDB-736] Query performance tracing[2].
I try to provide the performance tracing function by adding a performance log and give a switch statement "Tracing on/off" to control whether to print this log, which is off by default. The log records including: 1. the query sql, and the start time of this query 2. the number of series paths 3. the number of distinct tsfiles, including sequence and unsequence 4. the number of chunks, and average size of each chunk. This pr concentrates on raw data query, it may modify something for aggregation query and group by query later. Please leave your opinions, thanks. [1] https://github.com/apache/incubator-iotdb/pull/1399 [2] https://issues.apache.org/jira/projects/IOTDB/issues/IOTDB-736 -- Best, Xiangwei Wei
