exists¶
Type of operation: Join
Description¶
Return the rows from the default dataset that have a match anywhere in the query time window. (Non-temporal semijoin).
Usage¶
exists [ frame ], predicate_1, predicate_2, ...
Argument |
Type |
Optional |
Repeatable |
Restrictions |
---|---|---|---|---|
frame |
frame |
yes |
no |
constant |
predicate |
bool |
no |
yes |
none |
Accelerable¶
exists 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¶
exists [email protected]_id
Semijoin the default dataset with the ‘right’ dataset, returning rows from ‘default’ where there exists a key match at any point in time within the query window.
exists frame(back:30m), [email protected]_id
Semijoin the default dataset with the ‘right’ dataset, returning rows from ‘default’ where there exists a key match within 30 minutes in time.
exists [email protected]_id and sensor_value>@right.sensor_value
Semijoin the default dataset with the ‘right’ dataset, returning rows from ‘default’ where sensor_value
is greater than the value from ‘right’ for the same sensor_id
at any point in time within the query window.