[jira] [Commented] (CRUNCH-480) AvroParquetFileSource doesn't properly configure user-supplied read schema

["Josh Wills (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CRUNCH-480?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14200171#comment-14200171 ] 

Josh Wills commented on CRUNCH-480:
-----------------------------------

Is there a Parquet issue that fixes the underlying problem that I should keep an eye on?

I don't see how to communicate the readSupportMetadata to the InputFormat right now-- is this on a later version of Parquet than the one we're using here?

> AvroParquetFileSource doesn't properly configure user-supplied read schema
> --------------------------------------------------------------------------
>
>                 Key: CRUNCH-480
>                 URL: https://issues.apache.org/jira/browse/CRUNCH-480
>             Project: Crunch
>          Issue Type: Bug
>          Components: IO
>    Affects Versions: 0.10.0
>            Reporter: E. Sammer
>            Priority: Blocker
>
> It seems like AvroParquetFileSource doesn't properly set the configuration param required to use a user-supplied read schema that differs from the schema in the file.
> Deep in the guts of Parquet (InternalParquetReader#initialize()), I found this:
> {code}
>    this.recordConverter = readSupport.prepareForRead(
>         configuration, extraMetadata, fileSchema,
>         new ReadSupport.ReadContext(requestedSchema, readSupportMetadata));
> {code}
> Later, in Parquet's AvroReadSupport#prepareForRead(), it appears to ignore the supplied requestedSchema and, instead, looks for the key avro.read.schema in the readSupportMetadata map. This is seriously kookie code in Parquet (i.e. wrong), but because Crunch doesn't supply readSupportMetadata, we can never properly supply a read schema. Boooo hisssss.



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