follow_not¶
Type of operation: Join
Description¶
Return the rows from the joined dataset that do not have a match anywhere in the query time window.
follow_not
performs a non-temporal antisemijoin. The join will select any rows from the first dataset that do not have at least one matching row in the second dataset.
Usage¶
follow_not [ frame ], predicate_1, predicate_2, ...
Argument |
Type |
Optional |
Repeatable |
Restrictions |
---|---|---|---|---|
frame |
frame |
yes |
no |
constant |
predicate |
bool |
no |
yes |
none |
Accelerable¶
follow_not is accelerable if there is a frame() argument. A dataset that only uses accelerable verbs can be accelerated, making queries on the dataset respond faster.
Examples¶
follow_not [email protected]_id
Antisemijoin the default dataset with the ‘right’ dataset, returning rows from ‘right’ where there does not exists a key match at any point in time within the query window.
follow_not frame(back:30m), [email protected]_id
Antisemijoin the default dataset with the ‘right’ dataset, returning rows from ‘right’ where there does not exists a key match within 30 minutes in time.