Copy data from one table to other in Cassandra using Java -


i trying move data 1 column-family (table) other. since both tables have different descriptions, have pull data table-1 , create new object table-2 , bulk aync insert. table-1 has millions of records cannot data directly in data structure , work out. looking out solutions using spring data cassandra java.

i planned moving data temp table first followed creating composite key relations , querying master table. however, doesn't seems favorable me. can suggest strategy this? leads appreciated. thanks!

my table-1 has millions of records cannot data directly in data structure , work out.

with datastax java driver can data token ranges , work out data each token range. example:

set<tokenrange> tokenranges = cassandrasession.getcluster().getmetadata().gettokenranges();  for(tokenrange tr: tokenranges) {     list<row> rows = new arraylist<>();     for(tokenrange sub: tr.unwrap()){         string query = "select * keyspace.table token(pk) > ? , token(pk) <= ?";         simplestatement st = new simplestatement( query, sub.getstart(), sub.getend() );         rows.addall( session.execute( st ).all() );     }     transformandwritetonewtable(rows);  }

each token range contains piece of data , can handled 1 physical machine. can handle each token range independently (in parallel or asynchronously) more performance.


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