[jira] [Commented] (IOTDB-587) TsFile version 2

["Jialin Qiao (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/IOTDB-587?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17081620#comment-17081620 ] 

Jialin Qiao commented on IOTDB-587:
-----------------------------------

[https://github.com/apache/incubator-iotdb/pull/855]

> TsFile version 2
> ----------------
>
>                 Key: IOTDB-587
>                 URL: https://issues.apache.org/jira/browse/IOTDB-587
>             Project: Apache IoTDB
>          Issue Type: Improvement
>          Components: Core/Engine, Core/TsFile
>            Reporter: Jialin Qiao
>            Priority: Major
>             Fix For: 0.10.0-SNAPSHOT
>
>
> This issue it to record the TsFile version 2.
> In TsFile version 1 (rel/0.9), the ChunkMetadata is stored by device. If we want to query one series, we need to read ChunkMetadatas of all measurements of its device, which is time-consuming.
> Therefore, we want to avoid this unnecessary cost. The solution is decreasing the granularity of ChunkMetadata from device to each series.
> In the new version, the ChunkMetadata is grouped by each time series. If we want to query one series, we only need to read ChunkMetadata of this series. A file level statistics TimeseriesMetadata is added for each series to accelerate aggregations.
> Besides, by modifying the schema management of TsFile, the constraints that measurements that have the same name in one storage group should have the same data type is removed.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)