Questions about Columns and Families

[Samuru Jackson <sa...@googlemail.com>]

Hi,

I have two question regarding the usage of columns within a family:

1. Is there any limitation about the number of columns inside a column
family associated to a row (i.e. maximum number of columns)?
2. Is there any pagination possible for columns? If I have a huge
number of columns for a row I don't want to retrieve all of them at
once, but paging through them.

Thanks

/SJ

Re: Questions about Columns and Families

[Andrey Stepachev <oc...@gmail.com>]

2010/8/16 Samuru Jackson <sa...@googlemail.com>:
> Hi,
>
> I have two question regarding the usage of columns within a family:
>
> 1. Is there any limitation about the number of columns inside a column
> family associated to a row (i.e. maximum number of columns)?

Wide family can have poor scalability, because table splits on key ranges.
If you will have very wide family it will live on 1 region server and
doesnt' slit.
Another drawback - if you you want to take some range of values
hbase will scan whole row, in opposite to keys. With compound keys
you can use scan to get range of values.


> 2. Is there any pagination possible for columns? If I have a huge
> number of columns for a row I don't want to retrieve all of them at
> once, but paging through them.

Only in trunk. https://issues.apache.org/jira/browse/HBASE-1537

>
> Thanks
>
> /SJ
>