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https://issues.apache.org/jira/browse/PARQUET-131?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14224001#comment-14224001
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Dong Chen commented on PARQUET-131:
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Hi [~brocknoland]
bq. in Hive ColumnVector.isRepeating is used when it's a partition column
I think using for a partition column is one case, and it can also used for
normal columns, if the values are same in one column.
In Hive, when the {{VectorExpression}} in {{Operator}} consume the
{{ColumnVector}}, it will check {{isRepeating}} first. If true, it will skip
the array loop and just fetch the 1st element in the vector for computation.
> Supporting Vectorized APIs in Parquet
> -------------------------------------
>
> Key: PARQUET-131
> URL: https://issues.apache.org/jira/browse/PARQUET-131
> Project: Parquet
> Issue Type: Improvement
> Components: parquet-mr
> Reporter: Zhenxiao Luo
> Assignee: Zhenxiao Luo
>
> Vectorized Query Execution could have big performance improvement for SQL
> engines like Hive, Drill, and Presto. Instead of processing one row at a
> time, Vectorized Query Execution could streamline operations by processing a
> batch of rows at a time. Within one batch, each column is represented as a
> vector of a primitive data type. SQL engines could apply predicates very
> efficiently on these vectors, avoiding a single row going through all the
> operators before the next row can be processed.
> As an efficient columnar data representation, it would be nice if Parquet
> could support Vectorized APIs, so that all SQL engines could read vectors
> from Parquet files, and do vectorized execution for Parquet File Format.
>
> Detail proposal:
> https://gist.github.com/zhenxiao/2728ce4fe0a7be2d3b30
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