Just curious, won't ROWCOL bloom filter works for this case? Best Regards, Raymond Liu
> > As per the above said, you will need a full table scan on that CF. > As Ted said, consider having a look at your schema design. > > -Anoop- > > > On Sun, Mar 10, 2013 at 8:10 PM, Ted Yu <yuzhih...@gmail.com> wrote: > > > bq. physically column family should be able to perform efficiently > > (storage layer > > > > When you scan a row, data for different column families would be > > brought into memory (if you don't utilize HBASE-5416) Take a look at: > > > > > https://issues.apache.org/jira/browse/HBASE-5416?focusedCommentId=1354 > > 1258&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabp > > anel#comment-13541258 > > > > which was based on the settings described in: > > > > > > > https://issues.apache.org/jira/browse/HBASE-5416?focusedCommentId=1354 > > 1191&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabp > > anel#comment-13541191 > > > > This boils down to your schema design. If possible, consider > > extracting column C into its own column family. > > > > Cheers > > > > On Sun, Mar 10, 2013 at 7:14 AM, PG <pengyunm...@gmail.com> wrote: > > > > > Hi, Ted and Anoop, thanks for your notes. > > > I am talking about column rather than column family, since > > > physically column family should be able to perform efficiently > > > (storage layer, CF's are stored separately). But columns of the same > > > column family may be > > mixed > > > physically, and that makes filters column value hard... So I want to > > > know if there are any mechanism in HBase worked on this... > > > Regards, > > > Yun > > > > > > On Mar 10, 2013, at 10:01 AM, Ted Yu <yuzhih...@gmail.com> wrote: > > > > > > > Hi, Yun: > > > > Take a look at HBASE-5416 (Improve performance of scans with some > > > > kind > > of > > > > filters) which is in 0.94.5 release. > > > > > > > > In your case, you can use a filter which specifies column C as the > > > > essential family. > > > > Here I interpret column C as column family. > > > > > > > > Cheers > > > > > > > > On Sat, Mar 9, 2013 at 11:11 AM, yun peng <pengyunm...@gmail.com> > > wrote: > > > > > > > >> Hi, All, > > > >> I want to find all existing values for a given column in a HBase, > > > >> and > > > would > > > >> that result in a full-table scan in HBase? For example, given a > > > >> column > > > C, > > > >> the table is of very large number of rows, from which few rows > > > >> (say > > > only 1 > > > >> row) have non-empty values for column C. Would HBase still ues a > > > >> full > > > table > > > >> scan to find this row? Or HBase has any optimization work for > > > >> this > > kind > > > of > > > >> query? > > > >> Thanks... > > > >> Regards > > > >> Yun > > > >> > > > > >
