From RedBean

Meta Data

OODBBeans contain meta information; for instance the type of the bean. This information is hidden in a meta information field. You can use simple accessors to get and modify this meta information.

Fetching Meta Data

To get a meta property value:

$value = $bean->getMeta("my.property", $defaultIfNotExists);

The default default value is NULL.

Changing or Adding Meta Data

To set a meta property simply use a dot separated notation; preceding nodes do not have to exist; the system will create them automatically.

$bean->setMeta("type", "newtable"); //changes the table

To make Redbean add a unique index for several columns:

$bean->setMeta("buildcommand.unique.0",
  array( "column1", "column2", "column3") );