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Avro >> mail # user >> Random access in an avro file


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Re: Random access in an avro file
Thanks for the reply Doug.

Out of curiosity, is maintaining sync markers while writing the file and
then passing these markers to the readers while reading not a good way to
achieve random access in avro? Atleast that's what my understanding from
reading the javadoc[1] was, which could be flawed.

[1]
http://avro.apache.org/docs/1.3.3/api/java/org/apache/avro/file/DataFileWriter.html#sync()
On Mon, Jul 1, 2013 at 12:05 PM, Doug Cutting <[EMAIL PROTECTED]> wrote:

> Avro data files do not generally support random access.
>
> SortedKeyValueFile supports random access by key.
>
>
> http://avro.apache.org/docs/current/api/java/org/apache/avro/hadoop/file/SortedKeyValueFile.Reader.html
>
> From the documentation:
>
> "The SortedKeyValueFile is a directory with two files, named 'data'
> and 'index'. The 'data' file is an ordinary Avro container file with
> records. Each record has exactly two fields, 'key' and 'value'. The
> keys are sorted lexicographically. The 'index' file is a small Avro
> container file mapping keys in the 'data' file to their byte
> positions. The index file is intended to fit in memory, so it should
> remain small. There is one entry in the index file for each data block
> in the Avro container file."
>
> Doug
>
> On Mon, Jul 1, 2013 at 8:37 AM, [EMAIL PROTECTED]
> <[EMAIL PROTECTED]> wrote:
> > Hello,
> >
> > Is it possible to have random access to a record in an avro file? For
> > instance, if I have an avro file with a schema containing four records:
> > employee id, name, address and phone. While reading the file, is there
> any
> > way at all to directly jump to a record with employee id 100 instead of
> > having to scan the whole file every single time and filtering out
> records?
> >
> > Thanks for the help.
> >
> > --
> > Swarnim
>

--
Swarnim