Thanks a lot. Maybe i will go with server-side filters. On Tue, Aug 18, 2009 at 3:24 AM, Bradford Stephens < [email protected]> wrote:
> Just reiterating with JGray says -- usually, when you need a secondary > index, you can get away with denormalizing and duplicating your data. > > On Mon, Aug 17, 2009 at 9:30 AM, Jonathan Gray<[email protected]> wrote: > > This is possible by checking the values in your client, through > server-side > > filters (see org.apache.hadoop.hbase.filter), or with secondary indexing > (as > > described in my previous e-mail). > > > > In the first two cases, you are doing a full table scan so it is very > > inefficient. That's the same as it would be in an RDBMS if you were not > > using secondary indexes, however. > > > > HBase has limited secondary indexing support, but do not expect the > > flexibility and performance you get from an RDBMS secondary index. > > > > If this is central to your usage of HBase, make sure that HBase is what > you > > want and take another look at your schema to see if there might be a > better > > design to prevent needing heavy indexing or table scanning. > > > > JG > > > > Rocks wrote: > >> > >> Thanks for you answer. > >> however, what i want to do just likes "where" keyword of SQL in RDBMS. > Is > >> it impossible in hbase ? > >> > >> On Mon, Aug 17, 2009 at 2:58 PM, Ryan Rawson <[email protected]> > wrote: > >> > >>> hey, > >>> > >>> That isn't how hbase (or even rdbms) work. Instead you can retrieve > >>> rows based on their row key. Otherwise you will have to read the > >>> entire table to find just that 1 row. Yes this is as inefficient as it > >>> sounds. > >>> > >>> If you frequently have this issue, you may need to build and maintain > >>> secondary indexes. Unlike relational dbs, there is no built in support > >>> for this, you have to write your app to handle this. > >>> > >>> -yran > >>> > >>> > >>> > >>> On Sun, Aug 16, 2009 at 11:51 PM, lei wang<[email protected]> > >>> wrote: > >>>> > >>>> Hi, if a know a cell in a hbase for its column:<qualifer>:value, i > need > >>> > >>> to > >>>> > >>>> know which row key it belongs to. I searched the HBase api several > >>>> times, > >>>> but i can not find the right method to solve my problem. Thanks for > >>>> one's > >>>> suggestion to me. > >>>> > >> > > > > > > -- > http://www.roadtofailure.com -- The Fringes of Scalability, Social > Media, and Computer Science >
