A Humio query is much like a query to an SQL database. You write search terms to include or exclude values from a repository or view. Unlike most queries SQL, in Humio, you also do calculations and transform the data as part of the query.
To learn Humio's query language head over to the Query Language reference page.
Some filter, some transform and augment, others aggregate data into result sets like tables or bucketed time series.
Figure 314. Day of Week
Transformation expressions (also called Filter expressions) filter input or adds/removes/modifies fields on each event. These include filter expressions like:
This uses the
time:dayOfWeekName() function to
extract the day of the week from the timestamp for each event, and then
format that value so as to return the name of the day of the week
— and put that value in a field named, the day. You can see the
results in the screenshot in Figure 1 here.
A subset of the available query functions are known as Transformation
Functions, for example
eval(). Just like the
examples above they only adds/removes/modifies fields and never produce
new (additional) events as output.
If a query consists solely of transformation expressions it is known as filter query or transformation query. This kind of query are required when connecting Views with repositories.
Aggregation expressions are always function calls. These functions can combine their input into a new structures or emit new events into the output stream.
For example, the query
count() takes a stream of
events as its input, and produces a single record containing a
Below are some examples:
loglevel = ERROR | timechart()