make_reference¶
Type of operation: Aggregate, Metadata
Description¶
Create a reference table by aggregating data over time. The output dataset is efficiently maintained as new data arrives.
If groupby is not specified, the default grouping will be used. The default grouping is the set of primary key columns.
Usage¶
make_reference [ groupby_1, groupby_2, ... ], groupOrAggregateFunction_1, groupOrAggregateFunction_2, ...
Argument |
Type |
Optional |
Repeatable |
Restrictions |
|---|---|---|---|---|
groupby |
storable |
yes |
yes |
column |
groupOrAggregateFunction |
expression |
no |
yes |
none |
Options¶
Option |
Type |
Meaning |
|---|---|---|
expiry |
duration |
How long a group lifetime is extended after an observed state change. |
Accelerable¶
make_reference is always accelerable if the input is accelerable. A dataset that only uses accelerable verbs can be accelerated, making queries on the dataset respond faster.
Examples¶
make_reference Count:count(), group_by(server_name)
Group input data by server name, calculating a count of rows per server name, returning a dataset with the two columns server_name and Count.