OPAL Metadata Verbs

Metadata verbs modify the metadata of the dataset and the columns in the dataset, rather than directly acting on the data itself.

Certain metadata verbs may affect how the dataset is presented, such as whether column links are shown, or whether data is packed.

Verb	Description
add_key	Add a candidate key to the output.
interface	Map fields of this dataset to a pre-defined interface.
make_event	Creates an Event dataset from an input Table, Interval, or Resource dataset.
make_interval	Creates an Interval dataset from an input Table or Event dataset.
make_resource	Creates a Resource dataset from an input Event or Interval dataset.
make_session	Group events or intervals that are close to each other into sessions, and calculate aggregations over each session.
make_table	Creates a Table dataset from an input Event, Interval, or Resource dataset.
merge_events	Merge consecutive events into new events based on merge conditions.
set_col_enum	Mark columns as enumerations, or not, by name.
set_col_immutable	Mark resource columns as time immutable (time-invariant), or not.
set_col_visible	Show or hide columns by name.
set_label	Declare the ‘label’ of the output to be the designated column.
set_link	Add a foreign key to the output.
set_metric	Register a metric, with its metadata defined in an options object.
set_primary_key	Declare the primary key of the output as consisting of one or more named columns.
set_valid_from	Declare the valid from of the output to be the named column.
set_valid_to	Declare the ‘valid to’ of the output to be the named column.
sort	Sort rows in the dataset based on ordering functions applied to column fields or column name provided as arguments.
unset_all_links	Drop all outbound links without having to specify the individual labels.
unset_keys	Remove the primary and candidate key declarations from the dataset.
unset_link	Drop a foreign key by specifying the foreign keys label.