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apache / carbondata / fd2cc2a79dc62cd78b3ea7ac363858472ad78ac1
commitfd2cc2a79dc62cd78b3ea7ac363858472ad78ac1[log] [tgz]
authorhaomarch <marchpure@126.com>Tue Oct 13 23:10:58 2020 +0800
committerQiangCai <qiangcai@qq.com>Tue Nov 03 17:01:12 2020 +0800
tree9eeeb60a054876dde73f4cde395bfe0a08868c86
parent4a729e10f75ea3c5b99540e089b9dfb204bb84f5 [diff]
[CARBONDATA-4044] Fix dirty data in index file while IUD with stale data in segment folder

Why is this PR needed?
XX.mergecarbonindex and XX..segment records the indexfiles list of a segment. now, we generate xx.mergeindexfile and xx.segment  based on filter out all indexfiles(including carbonindex and mergecarbonindex), which will leading dirty data when there is stale data in segment folder.
For example, there are a stale index file in segment_0 folder, "0_1603763776.carbonindex".
While loading, a new carbonindex "0_16037752342.carbonindex" is wrote, when merge carbonindex files, we expect to only merge 0_16037752342.carbonindex, But If we filter out all carbonindex in segment folder, both "0_1603763776.carbonindex" and 0_16037752342.carbonindex will be merged and recorded into segment file.
While updating, there has same problem.

What changes were proposed in this PR?
1. IUD: merge file based on UUID(timestamp).
2. IUD: write segment file based on UUID(timestamp).
3. Update: update will generate a new segment to avoid rewrite segment file. also will rollback the new segment when update fails
4. We delete horizotal compaction processing of update delta(both carbondata files and carbonindex).
5. Clean the dead code when update write into new segment
6. Fix an update issue: The wrong update result after drop partition.

Does this PR introduce any user interface change?
Yes

Is any new testcase added?
Yes

This closes #3999
40 files changed
tree: 9eeeb60a054876dde73f4cde395bfe0a08868c86
  1. .github/
  2. assembly/
  3. bin/
  4. build/
  5. common/
  6. conf/
  7. core/
  8. dev/
  9. docs/
  10. examples/
  11. format/
  12. geo/
  13. hadoop/
  14. index/
  15. integration/
  16. licenses-binary/
  17. mv/
  18. processing/
  19. python/
  20. sdk/
  21. streaming/
  22. tools/
  23. .gitignore
  24. LICENSE
  25. NOTICE
  26. pom.xml
  27. README.md
  28. scalastyle-config.xml
README.md

Apache CarbonData is an indexed columnar data store solution for fast analytics on big data platform, e.g.Apache Hadoop, Apache Spark, etc.

You can find the latest CarbonData document and learn more at: http://carbondata.apache.org

CarbonData cwiki

Visit count: HitCount

Status

Spark2.4: Build Status Coverage Status

Features

CarbonData file format is a columnar store in HDFS, it has many features that a modern columnar format has, such as splittable, compression schema ,complex data type etc, and CarbonData has following unique features:

  • Stores data along with index: it can significantly accelerate query performance and reduces the I/O scans and CPU resources, where there are filters in the query. CarbonData index consists of multiple level of indices, a processing framework can leverage this index to reduce the task it needs to schedule and process, and it can also do skip scan in more finer grain unit (called blocklet) in task side scanning instead of scanning the whole file.
  • Operable encoded data :Through supporting efficient compression and global encoding schemes, can query on compressed/encoded data, the data can be converted just before returning the results to the users, which is “late materialized”.
  • Supports for various use cases with one single Data format : like interactive OLAP-style query, Sequential Access (big scan), Random Access (narrow scan).

Building CarbonData

CarbonData is built using Apache Maven, to build CarbonData

Online Documentation

Experimental Features

Some features are marked as experimental because the syntax/implementation might change in the future.

  1. Hybrid format table using Add Segment.
  2. Accelerating performance using MV on parquet/orc.
  3. Merge API for Spark DataFrame.
  4. Hive write for non-transactional table.

Integration

Other Technical Material

Fork and Contribute

This is an active open source project for everyone, and we are always open to people who want to use this system or contribute to it. This guide document introduce how to contribute to CarbonData.

Contact us

To get involved in CarbonData:

About

Apache CarbonData is an open source project of The Apache Software Foundation (ASF).