OPAL Join Verbs

Join verbs link multiple datasets together. They may generate more, fewer, or the same number of output rows as input rows, depending on the join condition and verb.

Verb	Description
exists	Return the rows from the default dataset that have a match anywhere in the query time window.
follow	Return the rows from the additional joined dataset that have a match anywhere in the query time window.
fulljoin	Temporal full join, adding new columns in the output dataset.
join	Temporal inner join, adding new columns in the output dataset.
leftjoin	Temporal left join, adding new columns in the output dataset.
lookup	Find matching rows in a Resource or Interval dataset, making new columns in the output dataset.
surrounding	Rows from the “right” dataset that fall within the specified frame of at least one row in the default dataset are unioned with the
union	Create a new dataset consisting of the rows from the main input and each of the arguments.
update_resource	Augments the input Resource dataset using events from another dataset.