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=13541258&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13541258 which was based on the settings described in: https://issues.apache.org/jira/browse/HBASE-5416?focusedCommentId=13541191&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 > >> >
