Creating or altering tables to use DSE In-Memory

Creating a table to use DSE In-Memory 

To create a table that uses DSE In-Memory, add a CQL directive to the CREATE TABLE statement. Use the compaction directive in the statement to specify the MemoryOnlyStrategy class, disable compression, and disable the key and row caches.

CREATE TABLE customers (
  uid text,
  fname text,
  lname text,
  PRIMARY KEY (uid) 
) WITH compaction= { 'class': 'MemoryOnlyStrategy' }
     AND compression = {'sstable_compression' : ''}
     AND caching = {'keys':'NONE', 'rows_per_partition':'NONE'};

Altering an existing table to use DSE In-Memory 

Use the ALTER TABLE statement to change a traditional table to use in-memory, or to change an in-memory table to a traditional table. For example, use the DESCRIBE command for a table named employee. Verify that employee is a traditional table because the output of the DESCRIBE command does not include a line that looks something like:

compaction={'class': 'MemoryOnlyStrategy'} >

Alter the employee table to use DSE In-Memory and, as a best practice, disable caching:

ALTER TABLE employee WITH compaction= { 'class': 'MemoryOnlyStrategy' }
  AND compression = {'sstable_compression' : ''}
  AND caching = {'keys':'NONE', 'rows_per_partition':'NONE'};

nodetool upgradesstables -a <keyspacename> <tablename>

Use the --jobs option to set the number of SStables that upgrade simultaneously. The default setting is 2, which minimizes impact on the cluster. Set to 0 to use all available compaction threads.

CREATE TABLE employee (
  uid text PRIMARY KEY,
  fname text,
  lname text
) WITH bloom_filter_fp_chance = 0.01
  AND caching = '{"keys":"NONE", "rows_per_partition":"NONE"}'
  AND comment = ''
  AND compaction = {'min_threshold': '4', 'class': 'org.apache.cassandra.db.compaction.MemoryOnlyStrategy', 
'max_threshold': '32'}
  AND compression = {}
  AND dclocal_read_repair_chance = 0.1
  AND default_time_to_live = 0
  AND gc_grace_seconds = 864000
  AND max_index_interval = 2048
  AND memtable_flush_period_in_ms = 0
  AND min_index_interval = 128
  AND read_repair_chance = 0.0
  AND speculative_retry = '99.0PERCENTILE';

Limiting the size of tables 

Disabling caching on tables 

ALTER TABLE customers WITH caching = {'keys':'NONE', 
  'rows_per_partition':'NONE'};