Learn more about the Cortex Query Language first aggregate comp function that returns the first field value found in the dataset with the matching criteria.
Syntax
comp first(<field>) [as <alias>] by <field_1>,<field_2> [addrawdata = true|false [as <target field>]]
Description
The first aggregation is a comp function that returns a single first value found for a field in the dataset over a group of rows that has matching values for the fields identified in the by clause. This function is dependent on a time-related field, so for your query to be considered valid, ensure that the dataset running this query contains a time-related field. This function is used in combination with a comp stage.
In addition, you can configure whether the raw data events are displayed by setting addrawdata to either true or false (default), which are used to configure the final comp results. When including raw data events in your query, the query runs for up to 50 fields that you define and displays up to 100 events.
Examples
Return the first timestamp found in the dataset for any given action_total_download value for all records that have matching values for their actor_process_image_path and actor_process_command_line fields. The query calculates a maximum of 100 xdr_data records and includes a raw_data column listing the raw data events used to display the final comp results.
dataset = xdr_data | fields _time,actor_process_image_path as Process_Path, actor_process_command_line as Process_CMD, action_total_download as Download | filter Download > 0 | limit 100 | comp first(_time) as download_time by Process_Path, Process_CMD addrawdata = true as raw_data