hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From c...@poczta.xg.pl
Subject Re: how to - get last inserted row id
Date Mon, 25 Feb 2008 21:41:50 GMT


On Mon, 25 Feb 2008, Bryan Duxbury wrote:

>
> It seems to me that the only time you should use random GUIDs as row
> keys is if you don't care about the keys or the ordering of rows,
> since they're sorted lexically, and GUIDs are distributed randomly.
> If you want to find the last 100 inserted, you should make your keys
> timestamps instead. Then it'd be easier to find your way to the end.
> You'd still have to scan the last region of the table to find the
> last 100, but at least it would be doable.

  thank - this can be help full and i will check it.

> There is also no way to join tables in HBase. HBase is not a
> relational database, so if you want to "join" two tables, you need to
> do so on your own with two scanners, and probably in a map/reduce
> job. However, you should consider denormalizing your data some, as
> HBase rows can store 1:n relationships ok with column families. See
> the Bigtable discussion of Webtable for some ideas of how this might
> work.

  yeah, i know that there are no "join" - i just have sugest to create
page : "thinking in column-based databases". maby some comparsion of RDBMS
and column-based, study of the examples, when to use ...
 it will be very usefull for new users of hbase and other bases.

      Thx Antony


Mime
View raw message