The Ultimate Guide to High Availability with MariaDB

ColumnStore Create Table

  1. Syntax
  2. Notes:

A database consists of tables that store user data. You can create multiple columns with the create table statement. The data type follows the column name when adding columns.

Syntax

CREATE TABLE [IF NOT EXISTS] tbl_name
    (create_definition,...)  
engine=columnstore  [ DEFAULT CHARSET=character-set] 
[COMMENT '[compression=0|1][;]


CREATE TABLE [IF NOT EXISTS] tbl_name
   { LIKE old_table_name | (LIKE old_table_name) }


create_definition:
    { col_name column_definition } 
column_definition:
    data_type
      [NOT NULL | NULL]
      [DEFAULT default_value]
      [COMMENT '[compression=0|1]
      [COMMENT='schema sync only'];

Notes:

  • ColumnStore tables should not be created in the mysql, information_schema, calpontsys or test databases.
  • ColumnStore stores all object names in lower case.
  • CREATE TABLE LIKE is supported starting from version MariaDB CoumnStore 1.2 and higher
  • CREATE TABLE AS SELECT is not supported, and will instead create the table in the default storage engine.
  • Compression level (0 for no compression, 1 for compression) can be set at the system level. If a session default exists, this will override the system default. In turn, this can be overridden by the table level compression comment, and finally a compression comment at the column level.
  • A table can be created in the front end only by using a ‘schema sync only’ comment. This could be useful when the table has been created on one user module, and needs to be synced to others.
  • The column DEFAULT value can be a maximum of 64 characters.
  • For maximum compatibility with external tools MariaDB ColumnStore will accept the following table attributes, however these are not implemented within MariaDB ColumnStore:
    • MIN_ROWS
    • MAX_ROWS
    • AUTO_INCREMENT
  • Datatype timestamp is not supported for Columnstore below 1.4. Caused a "The syntax or the data type(s) is not supported by Columnstore" error.

All of these are ignored by ColumnStore.The following statement creates a table called orders with two columns: orderkey with datatype integer and customer with datatype varchar:

CREATE TABLE orders (
  orderkey INTEGER, 
  customer VARCHAR(45)
) ENGINE=ColumnStore

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