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https://issues.apache.org/jira/browse/IOTDB-3100?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jialin Qiao reassigned IOTDB-3100:
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Assignee: (was: Haiming Zhu)
> Semantics change of TsFile filename
> -----------------------------------
>
> Key: IOTDB-3100
> URL: https://issues.apache.org/jira/browse/IOTDB-3100
> Project: Apache IoTDB
> Issue Type: Improvement
> Components: Core/Engine
> Reporter: Haiming Zhu
> Priority: Major
> Labels: pull-request-available
>
> Currently, the filename format of each tsfile is
> \{file_created_time}-\{version_id}-\{inner_space_merge_num}-\{cross_space_merge_num}.tsfile.
> In one time partition, the order of tsfiles is guaranteed by the version_id,
> for example, 1651825804093-2-0-0.tsfile is after 1651825804092-1-0-0.tsfile
>
> https://issues.apache.org/jira/projects/IOTDB/issues/IOTDB-3100?filter=myopenissues#
> The problem is that filename conflict may occur in the cross space compaction
> and load scenes. In the cross space compaction, assuming there exists
> 3-2-0-0.tsfile, 4-3-0-0.tsfile and 5-5-0-0.tsfile in the sequence folder, if
> file 4-3-0-0.tsfile is selected, compaction cannot generate 3 or more target
> files because only 2 version_id are left between 2 and 5, so some big target
> files may be generated. In the load, assuming there exists 3-2-0-0.tsfile,
> 3-3-0-0.tsfile and 3-3-0-0.tsfile in the sequence folder, no more sequence
> files cannot be loaded between 3-2-0-0.tsfile and 3-3-0-0.tsfile, they can
> only be loaded into the unsequence folder.
>
> In response to these problems, the format won't be changed, but the meaning
> of file_created_time and version_id will be different. Instead of version_id,
> we use file_created_time to guarantee the order of tsfiles, and if two
> tsfiles have the same file_created_time, then we use version_id to guarantee
> the order. This semantics change may afftect query, compaction and load
> module.
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