hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Carl M <soloning...@hotmail.com>
Subject Re: Is it possible to implement a NOT filter in Hbase?
Date Fri, 30 Dec 2016 12:53:57 GMT
Thanks Ted! Great idea replacing the value in filterKeyValue. Although I'm not quite sure looking
at FilterList code if only INCLUDE/SKIP should be replaced, and which should be the correct
replacement for INCLUDE_AND_NEXT_COL. What do you think? If not maybe i should try to implement
DeMorgan's law but I think it would be harder.


Best,

________________________________
De: Ted Yu <yuzhihong@gmail.com>
Enviado: jueves, 29 de diciembre de 2016 06:10 p.m.
Para: user@hbase.apache.org
Asunto: Re: Is it possible to implement a NOT filter in Hbase?

You can try negating the ReturnCode from filterKeyValue() (at the root of
FilterList):

  abstract public ReturnCode filterKeyValue(final Cell v) throws
IOException;

INCLUDE -> SKIP

SKIP -> INCLUDE

Alternatively, you can use De Morgan's law to transfer the condition:

 NOT (a = '123' AND b = '456') becomes

 (NOT a = '123') OR (b = '456')

On Thu, Dec 29, 2016 at 12:56 PM, Carl M <soloninguno@hotmail.com> wrote:

> Hi guys
>
>
> I'm trying to implement some kind of NOT filter in Hbase, but don't know
> if possible, I'm playing with FilterIfMissing and FilterList.Operator but
> without luck.
>
>
> I know how to return rows not having a specific column, but I mean
> something like returning rows NOT fullfilling a condition, where condition
> could be not only a SingleColumnValueFilter but a combined condition with
> FilterList. In SQL would be something like this for example
>
>
> SELECT * FROM table WHERE NOT (a = '123' AND b = '456');
>
>
> Thanks in advance,
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message