http://phoenix.apache.org/dynamic_columns.html
Sometimes defining a static schema up front is not feasible. Instead, a subset of columns may be specified at table create <http://phoenix.apache.org/language/index.html#create_table> time while the rest would be specified at query <http://phoenix.apache.org/language/index.html#select> time. As of Phoenix 1.2, specifying columns dynamically is now supported by allowing column definitions to included in parenthesis after the table in the FROM clause on a SELECT statement. Although this is not standard SQL, it is useful to surface this type of functionality to leverage the late binding ability of HBase. On Fri, Apr 24, 2015 at 1:38 AM, 丁桂涛（桂花） <dinggui...@baixing.com> wrote: > see the Phoenix FAQ > <http://phoenix.apache.org/faq.html#Are_there_any_tips_for_optimizing_Phoenix> > : > > > - Use *multiple column families* > > Column family contains related data in separate files. If you query use > selected columns then it make sense to group those columns together in a > column family to improve read performance. > > Example: > > Following create table DDL will create two column faimiles A and B. > > *CREATE TABLE TEST (MYKEY VARCHAR NOT NULL PRIMARY KEY, A.COL1 VARCHAR, > A.COL2 VARCHAR, B.COL3 VARCHAR)* > > On Fri, Apr 24, 2015 at 12:41 PM, Maria Catherine Tan <c...@exist.com> > wrote: > >> Hi, >> >> We're planning to use phoenix to create an HBase table with 2 column >> families both having dynamic columns. >> >> Already did some googling but I couldn't find an example on how to do >> that or if it's even possible. >> >> Can anyone point me in the right direction. >> >> >> Thanks, >> -- >> Maria Catherine Tan >> Software Engineer | Exist Software Labs | +6326874091 | skype: >> marica_tan | email: c...@exist.com | www.exist.com | Innovation Delivered >> > >
