lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Adrien Grand <>
Subject Re: Reading a v2 index in v4
Date Mon, 09 Jun 2014 12:17:37 GMT

It is not possible to read 2.x indices from Lucene 4, even with a
custom codec. For instance, Lucene 4 needs to hook into to detect old 3.x indices and force the use of the
Lucene3x codec since these indices don't expose what codec has been
used to write them.

On Mon, Jun 9, 2014 at 12:51 PM, Trejkaz <> wrote:
> Hi all.
> The inability to read people's existing indexes is essentially the
> only thing stopping us upgrading to v4, so we're stuck indefinitely on
> v3.6 until we find a way around this issue.
> As I understand it, Lucene 4 added the notion of codecs which can
> precisely choose how to read and write the index content.
> So I wonder:
> 1. Is it technically possible to write a codec to read the v2 format?
> 2. If this is possible, has anyone already done it?
>     (Surely we're not the first ones to want to do it.)
> TX
> ---------------------------------------------------------------------
> To unsubscribe, e-mail:
> For additional commands, e-mail:


To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message