In order to Enable or Disable the IM Column Store for Tables, your database must be with the Oracle Database In-Memory (Database In-Memory) option enabled. If not, see this post : https://www.techdatabasket.com/enabling-oracle-database-in-memory-database-in-memory-option-in-oracle-database-12c-release-1/ According to Oracle, “You enable a table for the IM column store by including an INMEMORY clause in a CREATE TABLE or ALTER TABLE statement. You disable a table for the IM column store by including a NO INMEMORY clause in a CREATE TABLE or ALTER TABLE statement.”. Then, in this post I am going to show you…