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ASF GitHub Bot commented on PARQUET-1381: ----------------------------------------- gszadovszky commented on pull request #621: Revert "PARQUET-1381: Add merge blocks command to parquet-tools (#512)" URL: https://github.com/apache/parquet-mr/pull/621 This reverts commit 863a081850e56bbbb38d7b68b478a3bd40779723. The design of this feature has conceptional problems and also works incorrectly. See PARQUET-1381 for more details. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org > Add merge blocks command to parquet-tools > ----------------------------------------- > > Key: PARQUET-1381 > URL: https://issues.apache.org/jira/browse/PARQUET-1381 > Project: Parquet > Issue Type: New Feature > Components: parquet-mr > Affects Versions: 1.10.0 > Reporter: Ekaterina Galieva > Assignee: Ekaterina Galieva > Priority: Major > Labels: pull-request-available > Fix For: 1.11.0 > > > Current implementation of merge command in parquet-tools doesn't merge row > groups, just places one after the other. Add API and command option to be > able to merge small blocks into larger ones up to specified size limit. > h6. Implementation details: > Blocks are not reordered not to break possible initial predicate pushdown > optimizations. > Blocks are not divided to fit upper bound perfectly. > This is an intentional performance optimization. > This gives an opportunity to form new blocks by coping full content of > smaller blocks by column, not by row. > h6. Examples: > # Input files with blocks sizes: > {code:java} > [128 | 35], [128 | 40], [120]{code} > Expected output file blocks sizes: > {{merge }} > {code:java} > [128 | 35 | 128 | 40 | 120] > {code} > {{merge -b}} > {code:java} > [128 | 35 | 128 | 40 | 120] > {code} > {{merge -b -l 256 }} > {code:java} > [163 | 168 | 120] > {code} > # Input files with blocks sizes: > {code:java} > [128 | 35], [40], [120], [6] {code} > Expected output file blocks sizes: > {{merge}} > {code:java} > [128 | 35 | 40 | 120 | 6] > {code} > {{merge -b}} > {code:java} > [128 | 75 | 126] > {code} > {{merge -b -l 256}} > {code:java} > [203 | 126]{code} -- This message was sent by Atlassian JIRA (v7.6.3#76005)