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Date: Mon, 28 Nov 2011 15:50:19 -0800
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 <CALte62xP--iMekwGvJVOwC0oGN+yk1NM59UDc2Of7fp55n9ing@mail.gmail.com>
Subject: Re: Compression.Algorithm extensibility?
From: Ted Yu <yuzhihong@gmail.com>
To: dev@hbase.apache.org
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https://issues.apache.org/jira/browse/HBASE-4887 has been created.

On Mon, Nov 28, 2011 at 3:42 PM, Doug Meil <doug.meil@explorysmedical.com>w=
rote:

>
> I'd vote for the full enum name in the file too instead of the ordinal.
>
>
>
> On 11/28/11 5:58 PM, "Todd Lipcon" <todd@cloudera.com> wrote:
>
> >Seems like we're doing some over-optimization here using ordinals. Why
> >not just write out the full enum name into the file? A few extra bytes
> >in the header of a multi-MB HFile hardly seems expensive.
> >
> >Could probably switch this over in a backward-compatible manner pretty
> >easily if someone has time to do the patch.
> >
> >-Todd
> >
> >On Mon, Nov 28, 2011 at 9:57 AM, Stack <stack@duboce.net> wrote:
> >> On Mon, Nov 28, 2011 at 8:26 AM, Doug Meil
> >> <doug.meil@explorysmedical.com> wrote:
> >>> Hi folks-
> >>>
> >>> In Compression.java there is this comment=C5=A0
> >>>
> >>>
> >>>  /**
> >>>
> >>>   * Compression algorithms. The ordinal of these cannot change or els=
e
> >>>you
> >>>
> >>>   * risk breaking all existing HFiles out there.  Even the ones that
> >>>are
> >>>
> >>>   * not compressed! (They use the NONE algorithm)
> >>>
> >>>   */
> >>>
> >>>  public static enum Algorithm {
> >>>
> >>> =C5=A0 which makes the prospect of adding new instances slightly
> >>>terrifying.  Has anybody considered changing the constructor to supply
> >>>an ordinal value, and that way if anybody adds a custom one they could
> >>>supply a value like 9999999 or something hopefully never used by HBase=
?
> >>>
> >>>
> >>
> >> The comment is just to warn against damage if ordinals are removed or
> >> reordered.  Do whatever it is you need to make it work Doug.  It
> >> should be possible to insert other compressors w/o gymnastics.
> >> St.Ack
> >>
> >
> >
> >
> >--
> >Todd Lipcon
> >Software Engineer, Cloudera
> >
>
>
>

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