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From "Doug Cutting (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (AVRO-680) Allow for non-string keys
Date Mon, 21 Jul 2014 22:10:39 GMT

     [ https://issues.apache.org/jira/browse/AVRO-680?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Doug Cutting updated AVRO-680:

    Attachment: AVRO-680.patch

Here's a slightly modified version of the patch.  In particular:
 - all changes are in a single patch file, the preferred format
 - wrap lines to 80 columns
 - ignore sign in hashing -- collisions already very unlikely but possible, preserving sign
does little to change that and makes names more confusing
 - changed Pair names to include hex of hash rather than decimal
 - removed 'reflect' from Pair name, since other impls should use same encoding if they decide
to support non-string map keys
 - perhaps a few other cosmetic changes

One thing I don't understand is the change in ReflectDatumWriter.  It's not clear to me how
the Pair schema generated permits one to write a collection of java.util.Map.Entry instances.
 How is this working?

> Allow for non-string keys
> -------------------------
>                 Key: AVRO-680
>                 URL: https://issues.apache.org/jira/browse/AVRO-680
>             Project: Avro
>          Issue Type: Improvement
>    Affects Versions: 1.7.6, 1.7.7
>            Reporter: Jeremy Hanna
>         Attachments: AVRO-680.patch, non_string_map_keys.zip, non_string_map_keys2.zip,
> Based on an email thread back in April, Doug Cutting proposed a possible solution for
having non-string keys:
> Stu Hood wrote:
> > I can understand the reasoning behind AVRO-9, but now I need to look for an alternative
to a 'map' that will allow me to store an association of bytes keys to values.
> A map of Foo has the same binary format as an array of records, each
> with a string field and a Foo field.  So an application can use an array
> schema similar to this to represent map-like structures with, e.g.,
> non-string keys.
> Perhaps we could establish standard properties that indicate that a
> given array of records should be represented in a map-like way if
> possible?  E.g.,:
> {"type": "array", "isMap": true, "items": {"type":"record", ...}}
> Doug

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