HBase: Create table with same schema as existing table

Here is the full-proof approach, I used. Hope it will help other people.

1) launch HBase shell vial below command

 hbase shell

2) Query existing table metadata with below command

 hbase> describe ‘existing_table’;

Output would be similar to:

{NAME => 'cf1', BLOOMFILTER => 'ROW', VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESSION => 'NONE', MIN_VERSIONS => '0', BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE => '0'}                                                                                                                  {NAME => 'cf2', BLOOMFILTER => 'ROW', VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESSION => 'NONE', MIN_VERSIONS => '0', BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE => '0'}

3) Copy this output to a notepad and do below changes:

  a) Replace  TTL => 'FOREVER' with TTL => org.apache.hadoop.hbase.HConstants::FOREVER  b) Put an additional comma (,) between each column family description to connect column family definition.  c) Remove newline characters (\n, \r) for the text; such that the content become one line text.

4) Finally running the create query with new table name:

create ‘copy_of_exsting_table_schema’, {NAME => 'cf1', BLOOMFILTER => 'ROW', VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE', DATA_BLOCK_ENCODING => 'NONE', TTL => org.apache.hadoop.hbase.HConstants::FOREVER, COMPRESSION => 'NONE', MIN_VERSIONS => '0', BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE => '0'} ,{NAME => 'cf2', BLOOMFILTER => 'ROW', VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE', DATA_BLOCK_ENCODING => 'NONE', TTL => org.apache.hadoop.hbase.HConstants::FOREVER, COMPRESSION => 'NONE', MIN_VERSIONS => '0', BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE => '0'}

And you are done. The new table schema is exactly same as existing table.

you can use snapshot feature to do this. like this;

hbase> snapshot 'tableName', 'tableSnapshot'hbase> clone_snapshot 'tableSnapshot', 'newTableName'hbase> delete_snapshot 'tableSnapshot'hbase> truncate 'newTableName'

i hope your table is not huge. And you can not copy column qualifiers with empty values, if i did not understand wrong, you mean this in your question. you can either copy all data to new table or only table structure with column families, coprocessors.. etc.