Page Comparison

Description

This operation returns all the values of a row in a historical time range lookup row into as a single JSON field upon successful key correlationmatching.

How does it work in the search window?

Select Create field in the search window toolbar, then select the Lookups category, and choose the Historical Lookup : retrieve json (hlurjson) operation from the dropdown (more info here). You need to specify three arguments:

Once you specify the adequate arguments and click the Create field button, the new field is added to your table.

Not only keys are correlated to return values but also the timestamps of both lookup and table. The timestamp in your table will be matched with the closest previous lookup timestamp to correlate key values. When retrieve the values of the lookup key field match the values of the Key argument, the new field displays all the values of the corresponding lookup row. If there is no match, it displays nullin the whole row when both keys match. Your new table field will display ranges of recurring values according to the time slot they belong to, which corresponds to the intervals between the lookup timestamps.

The data type of the values in the new column will be JSON. You can then split the resulting JSON objects into their different key/value pairs and transform them into different data types using the operations in the JSON group.

How does it work in LINQ?

Use the create field operator select... as new_field and add the operation syntax to create the new column. This is the syntax for the Historical lookup:retrieve json (hlurjson) operation:

...

• select hlurjson("Lookup_name", Key_field, Timestamp_field) as new_field

Existing lookups required

Example

We want to enrich the siem.logtrust.web.activity table with all the information about the working model in each city. If we want to work more comfortably, we can isolate the data we’re interested in by using filter and grouping operations. Then, we will use this upload lookup that contains info about company offices and the Historical lookup: retrieve json (hlurjson) operation.After performing the operations you need to manipulate your data, such as filtering and grouping operations, you can use the Lookup (hlurjson) operation to enrich your data with the following time range lookup:

• Lookup name: Enrichment

• Lookup fields: method, username, city (key), eventdate (timestamp)

These are the arguments needed when using the interface :

• Lookup name: Historical_company_offices Enrichment

• Key: city

• Time: eventdate

Complete example with screenshot of the arguments when development is in a more mature stage.

This is the syntax needed when using LINQ free-text query:

from siem.logtrust.web.activity
where isnotnull(city)
where not isempty(city)
where result = "OK"
group every 1h by city, result, regionmethod
select hlurjson("Historical_company_officesEnrichment", city, eventdate)

The table timestamp will be matched with the closest previous lookup timestamp, and the values in the entire lookup row will be brought into our your table when the values in the city field and those in the lookup key field fields match. When they do not match, null will be returned.

...

.