Tian Jiang created IOTDB-1264:
---------------------------------
Summary: Insert unseq file to seq files when possible
Key: IOTDB-1264
URL: https://issues.apache.org/jira/browse/IOTDB-1264
Project: Apache IoTDB
Issue Type: Improvement
Components: Core/Engine
Reporter: Tian Jiang
We judge if data belongs to the seq region or unseq region only by the
lastFlushedTime of each device, which makes the following situation possible:
2 seq files and their time ranges: seq1[0, 99], seq2[300, 500]
1 unseq file and its time range: unseq1[150, 200]
Intuitively, we can just make them 3 seq files, which may potentially reduce
query overhead.
One solution may be: right after we close one unseq file, we check if it
actually overlaps with any seq file(s), and if not, we insert it into a proper
position of the seq files instead of keeping it in unseq files. Another merit
is that this avoids the case mentioned in
https://github.com/apache/iotdb/pull/2920#pullrequestreview-623932806, because
each unseq file will definitely overlap at least one seq file.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
