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https://issues.apache.org/jira/browse/IOTDB-5807?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17716194#comment-17716194
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周沛辰 commented on IOTDB-5807:
----------------------------
*Bug Description*
# If the compression method of the aligned value series is different from that
of the time series, an error will be reported when decompressing.
# If the compression method of the aligned value series is different from that
of the time series, the target file will be corrupted.
*Reason*
# When reading the source file, all value columns share an uncompressor,
resulting in decompression failure.
# The compression method of the time column in the alignment timeseries takes
the first value column. If the source file is in the order of s0 s1 s2, and
during fast compaction, the read order is s1 s0 s2 and then written to the
target file in this order, that is , the time column of the original file is
actually compressed according to the s0 method, and the newly written time
column is compressed according to the s1 method, so if the compression method
of s1 is different from s0, the target file will be corrupted if flushing time
page or chunk directly.
*Solution*
# When reading files, each value column needs to have its own umcompressor.
# For the alignment timeseries, when writing a new file, the compression
method of the time column uses the default snappy; when rewriting the file, the
compression method of the time column is consistent with that of the source file
> Fix decompression error for aligned series in fast compaction
> -------------------------------------------------------------
>
> Key: IOTDB-5807
> URL: https://issues.apache.org/jira/browse/IOTDB-5807
> Project: Apache IoTDB
> Issue Type: Bug
> Affects Versions: 1.1.0
> Reporter: 周沛辰
> Assignee: 周沛辰
> Priority: Major
> Attachments: image-2023-04-25-17-17-39-762.png,
> image-2023-04-25-17-18-27-553.png, image-2023-04-25-17-20-27-105.png
>
> Original Estimate: 24h
> Remaining Estimate: 24h
>
> If the compression method of the aligned value series is different from that
> of the time series, an error will be reported when decompressing.
> !image-2023-04-25-17-20-27-105.png|width=738,height=432!
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