Matches or joins data from query results with a table. The table can be provided either as a lookup file — CSV file or through a limited form of JSON file, uploaded using Lookup Files — or as an ad-hoc table Using Ad-hoc Tables.

If you are looking for match expressions, see Match Statements.

ParameterTypeRequiredDefault ValueDescription
columnstring or arrayoptional[a] field parameter Which column in the file to use for the match. A single column or an array of columns can be specified.
fieldstring or arrayrequired   Which field in the event (log line) must match the given column value. A single field or an array of fields can be specified. Field and column must have the same length, are matched in order and must all match.
file[b]stringrequired   Specifies the source file (when using Look Up files) or the name of the ad-hoc table. The file name should be specified with .csv or .json suffix.
glob (deprecated)booleanoptional[a] false This parameter is deprecated. Use mode parameter with the glob option instead. (deprecated in 1.23)
ignoreCasebooleanoptional[a] false If true, ignore case when matching against the CSV data.
includestring or arrayoptional[a]   The columns to include. If no argument is given, include all columns from the corresponding row in the output event.
modestringoptional[a] string The function to use when matching against keys.
   Values
   cidrThe key is interpreted as a CIDR subnet and the event is matched if the field contains an IP within the subnet. If multiple subnets match, the most specific one is selected or an arbitrary one if there are multiple equally specific subnets.
   globThe key is interpreted as a globbing pattern with * and matched accordingly, for example, a CSV key value of *thisMatch* would match the field value of 123thisMatch456.
   stringThe matching is done using exact string matching.
strictbooleanoptional[a] true If true (the default) selects only the fields that match a key in the file; if false lets all events through (works like the deprecated lookup()).

[a] Optional parameters use their default value unless explicitly set.

[b] The parameter name file can be omitted.

Hide omitted argument names for this function

Show omitted argument names for this function

Hide negatable operation for this function

Show negatable operation for this function

When lookup information from files are loaded from a package, the package name should be specified in addition to the filename. For example:

logscale
match("falcon/investigate/logoninfo.csv",field="loookupname")

For more information on referring to package resources, see Referencing Package Assets.

The default behavior of this function — when strict is set to true — works like an INNER JOIN. When strict is set to false the function enriches events.

Note

Up until LogScale version 1.140, the file is limited to 1,000,000 rows/lines for exact matching using mode=string.

When using mode=glob, the underlying CSV is limited to 20,000 rows/lines.

For self-hosted customers, the maximum value for glob matches is configurable using GLOB_MATCH_LIMIT.

Using match() with Lookup Files

When using match() for joining with Lookup Files, two file formats are supported:

  • CSV. The recommended format, ensures better performance, allows for additional functionalities (using parameters) and is compatible with related functions, like readFile(). See CSV File Formats for more information.

  • JSON. Supports object and array-based formats. See JSON File Formats for more information.

CSV File Formats

For Comma Separated Values (CSV) files, whitespace gets included in the keys and values. To include the comma separator , in a value, quote using the " character. The following file is a valid CSV file:

csv
userid,name
1,chr
2,krab
"4","p,m"
7,mgr

The first line is interpreted as the column title. When querying, the column in the field should be used to identify which column to match against.

When using match() with a single column:

logscale
match(test.csv, field=somefield, column=column1)

the last matching row in test.csv is used.

itemvalue
field1c
field2e
column3f
itemvalue
field1c
column2e
column3f
field1c
column2d
column3a
itemvalue
field1c
column2e
column3f
field1c
column2d
column3a
field1c
column2b
column3a
methoddescriptionurl
POSTSend Data/humio/api/v1/ingest/elastic-bulk
POSTTransfer Data in/humio/api/v1/ingest/elastic-bulk
POSTTransfer Data in/humio/api/v1/ingest/elastic-bulk
POSTSend Data/humio/api/v1/ingest/elastic-bulk
POSTTransfer Data in/humio/api/v1/ingest/elastic-bulk
POSTSend Data/humio/api/v1/ingest/elastic-bulk

JSON File Formats

For JSON files, two formats are supported:

  • Object-based, where the lookup field does not have an explicit name

  • Array-based, where the information is an array of objects

In the Object-based variant, the lookup values are declared as an object with a key and embedded fields, the key field does not have a name.

json
{
  "1": { "name": "chr" },
  "2": { "name": "krab" },
  "4": { "name": "pmm" },
  "7": { "name": "mgr" }
}

Important

Nested JSON objects are not supported. Uploading a file with nested objects will not fail, but the information cannot be matched.

When matching against a file in this case, the name of the field in the JSON object does not need to be used; the key for each value is used instead. For example:

logscale
groupBy(@timezone)
| count(@timezone)
| match(file="short.json",field=_count)

In the above, the value of _count will be matched, outputting the match value:

_countname
2krab

In the array-based variant, the lookup values are declared as an array of objects, you select which field is the key using the field parameter in match().

json
[
  { "userid": "1", "name": "chr" },
  { "userid": "2", "name": "krab" },
  { "userid": "4", "name": "pmm" },
  { "userid": "7", "name": "mgr" }
]

When using this version, the name of the column to be matched must be specified using the column argument to match():

logscale
groupBy(@timezone)
| count(@timezone)
| match(file="long.json",field=_count,column="userid")

This behavior also means that any field in the JSON file can be used as the match value. For example:

logscale Syntax
...
| match(file="long.json",field=codename,column="name")

This can be useful if you have a JSON file that contains multiple possible lookup values for given records.

For

Important

The match() function does not report an error if the file format cannot be parsed.

match()Examples

Click + next to an example below to get the full details.

Match Multiple Pairs of Event Fields Against Multiple Columns in .CSV Lookup File

Compare multiple pairs of event fields against multiple columns in a .CSV lookup file using the match() function

Query
logscale
match(test.csv, field=[field1, field2], column=[column1, column2])
Introduction

In this example, the match() function is used to match multiple pairs of fields against multiple columns in a CSV file named test.csv simultaneously.

Example incoming event data might look like this:

Example test.csv file data might look like this:

column1column2column3
abd
cda
cef
Step-by-Step
  1. Starting with the source repository events.

  2. logscale
    match(test.csv, field=[field1, field2], column=[column1, column2])

    For each event, checks if field1 matches column1 and field2 matches column2

  3. Event Result set.

Summary and Results

The query is used to match multiple pairs of event fields against multiple columns in the .CSV file named test.csv. Multiple field matching helps validate and enrich complex event data.

Sample output from the incoming example data:

column3field1field2
fce

Filter For Items Not Part of Data Set Using !match()

Find the set difference using the match() function with negation

Query
logscale
src_ip=*
| !match("known_ips.csv", field=src_ip)
Introduction

In this example, the match() function is used with a negation to search and find IP addresses, that are not part of a known list known_ips.csv.

Example incoming data might look like this:

timestampsrc_ipdst_ipsrc_portdst_portprotocolbytes_sentbytes_received
2025-04-01T07:00:00Z192.168.1.10110.0.0.5052431443TCP10242048
2025-04-01T07:00:01Z172.16.0.248.8.8.83322153UDP64512
2025-04-01T07:00:02Z192.168.1.150172.16.0.1004922380TCP20484096
2025-04-01T07:00:03Z10.0.0.75192.168.1.15567822TCP5121024
2025-04-01T07:00:04Z192.168.1.2001.1.1.14455653UDP64512
Step-by-Step
  1. Starting with the source repository events.

  2. logscale
    src_ip=*

    Filters for all events that have a src_ip field.

  3. logscale
    | !match("known_ips.csv", field=src_ip)

    Excludes (filters out) any events where the src_ip field matches entries in the file known_ips.csv, and returns a list of IP addresses that are not found in the specified file. The negation operator is used to return non-matching results.

  4. Event Result set.

Summary and Results

The query is used to search for unknown or unexpected source IP addresses matched up againt a known list. This is useful for detecting potential security theats and monitoring for unauthorized network access.

Sample output from the incoming example data:

timestampsrc_ipdst_ipsrc_portdst_portprotocolbytes_sentbytes_received
2025-04-01T07:00:00Z192.168.1.10110.0.0.5052431443TCP10242048
2025-04-01T07:00:01Z172.16.0.248.8.8.83322153UDP64512

Match Event Fields Against Lookup Table Values

Compare event fields with column values in a lookup table using the match() function

Query
logscale
match(file="users.csv", column=userid, field=id, include=[])
Introduction

In this example, the match() function is used to match the column userid of the users.csv file against the id field in the event.

Step-by-Step
  1. Starting with the source repository events.

  2. logscale
    match(file="users.csv", column=userid, field=id, include=[])

    Matches events for which the id field matches the value of the column userid in the users.csv file (the lookup table file). All events with non-matching IDs are filtered out.

    No additional columns are added.

  3. Event Result set.

Summary and Results

The query is used to compare and match event fields and file values as strings, in this case using exact string matching (the default value of the mode parameter is string). The match() function is useful for comparing or combining data from multiple sources. In this example, only events with matching values are passed on, meaning that all events with non-matching IDs are removed. Matching events against an authorized users list is, for example, useful for filtering out unauthorized access attempts, for validation of user activities, or other monitoring.

Match Event Fields Against Lookup Table Values Adding Specific Columns

Compare event IP fields with CIDR ranges in lookup table using the match() function with mode parameter

Query
logscale
match(file="cidr-file.csv", column="cidr-block", field=ip, mode=cidr, include=["info","type"])
Introduction

In this example, the match() function is used to match event IP addresses against the column cidr-block of the cidr-file.csv file, adding specific columns details to the events.

The query matches IP addresses against CIDR blocks (CIDR subnets) and adds specific network information from the columns info and type to the output rows.

Example incoming event data might look like this:

@timestampipaction
2024-01-15T09:00:00.000Z10.0.1.25login
2024-01-15T09:01:00.000Z192.168.1.100connect
2024-01-15T09:02:00.000Z172.16.5.12access

Example cidr-file.csv file data might look like this:

cidr-blockinfotypelocationdepartment
10.0.1.0/24Internal NetworkcorporateHQIT
192.168.1.0/24Development NetworktestLabEngineering
172.16.0.0/16Production NetworkcriticalDCOperations
Step-by-Step
  1. Starting with the source repository events.

  2. logscale
    match(file="cidr-file.csv", column="cidr-block", field=ip, mode=cidr, include=["info","type"])

    Uses CIDR ranges matching to match the cidr-block column of the cidr-file.csv lookup table file against the IP addresses (ip field) in the events, and adds specific network information to the output rows.

    It will only add the specified columns of the matching row. The column names become new field names.

    Note that when the mode parameter is set to cidr, then the event is matched if the field contains an IP address within the CIDR subnet. If multiple subnets match, the most specific one is selected, or an arbitrary one, if there are multiple equally specific subnets.

  3. Event Result set.

Summary and Results

The query is used to match IP addresses against CIDR blocks and add specific network information from the columns info and type to the output rows.

The query helps analyze network traffic and security events by mapping IP addresses to network segments.

Sample output from the incoming example data:

@timestampipactioninfotype
2024-01-15T09:00:00.000Z10.0.1.25loginInternal Networkcorporate
2024-01-15T09:01:00.000Z192.168.1.100connectDevelopment Networktest
2024-01-15T09:02:00.000Z172.16.5.12accessProduction Networkcritical

Note how only the specified fields from the cidr-file.csv file appear in output.

Match Event Fields Against Lookup Table Values Allowing All Events to Pass

Compare event fields with column values in lookup table using the match() function with strict parameter to allow also non-matching events to pass

Query
logscale
id =~ match(file="users.csv", column=userid, strict=false)
Introduction

In this example, the match() function is used to match event IDs against the column userid of the users.csv file, adding the matching user details to the events. As the strict parameter is set to true, all events - including non-matching events - are passed through, but only events with matches will be enriched with all other columns of the matching row.

Example incoming event data might look like this:

@timestampidactionsource_ip
2024-01-15T09:00:00.000ZADMIN-123login10.0.0.1
2024-01-15T09:01:00.000Zunknown-userlogin_attempt10.0.0.2
2024-01-15T09:02:00.000Zdev-user-456code_push10.0.0.3

Example users.csv file data might look like this:

useriddepartmentaccess_levellocation
ADMIN-123ITadministratorHQ
dev-user-456EngineeringdeveloperRemote
Step-by-Step
  1. Starting with the source repository events.

  2. logscale
    id =~ match(file="users.csv", column=userid, strict=false)

    When an event ID matches the column userid in the users.csv lookup file, all columns from that first matching row are added to the event. The column names become new field names.

    As the strict parameter is set to true, all events - including non-matching events - are passed through, but only events with matches will be enriched with all other columns of the matching row.

  3. Event Result set.

Summary and Results

The query is used to enrich matching events while allowing all events to pass through. Matching events against an authorized users list is, for example, useful for filtering out unauthorized access attempts, for validation of user activities, or other monitoring. Showing non-matching events in output as well can, for example, be useful for tracking unauthorized access attempts, identifying unknown users or systems or for monitoring suspicious activities.

Sample output from the incoming example data:

@timestampidactionsource_ipdepartmentaccess_levellocation
2024-01-15T09:00:00.000ZADMIN-123login10.0.0.1ITadministratorHQ
2024-01-15T09:01:00.000Zunknown-userlogin_attempt10.0.0.2<no value><no value><no value>
2024-01-15T09:02:00.000Zdev-user-456code_push10.0.0.3EngineeringdeveloperRemote

After matching, the output combines original event fields with matched user details. Note how also non-matching events (in this example unknown-user) appear in output.

Match Event Fields Against Patterns in Lookup Table Values

Compare event fields with column values containing patterns in a lookup table using the match() function with glob pattern matching

Query
logscale
id =~ match(file="users.csv", column=userid, mode=glob, ignoreCase=true)
Introduction

In this example, the match() function is used with glob pattern matching (defined by the mode parameter) to match event IDs against the column userid of the users.csv file, adding the matching user details to the events.

Example incoming event data might look like this:

@timestampidactionsource_ip
2024-01-15T09:00:00.000ZADMIN-123login10.0.0.1
2024-01-15T09:01:00.000Zdev-user-456code_push10.0.0.2
2024-01-15T09:02:00.000ZTEST_789test_run10.0.0.3
2024-01-15T09:03:00.000Zsupport-001ticket_update10.0.0.4
2024-01-15T09:04:00.000Zunknown-userlogin_attempt10.0.0.5

Example users.csv file data might look like this:

useriddepartmentaccess_levellocationtitle
ADMIN-*ITadministratorHQSystem Administrator
dev-user-*EngineeringdeveloperRemoteSoftware Engineer
TEST_*QAtesterLabQA Engineer
support-*SupportagentOfficeSupport Specialist
Step-by-Step
  1. Starting with the source repository events.

  2. logscale
    id =~ match(file="users.csv", column=userid, mode=glob, ignoreCase=true)

    Uses glob pattern matching to match the userid column of the users.csv lookup table file against the IDs in the events. When an event ID matches a pattern in users.csv, all (non-pattern) columns from that first matching row are added to the event. The column names become new field names.

    Pattern matching examples based on the input data and lookup file are:

    ADMIN-123 matches ADMIN-*

    dev-user-456 matches dev-user-*

    TEST_789 matches TEST_*

    support-001 matches support-*

  3. Event Result set.

Summary and Results

The query is used to match event IDs against patterns in a user list, and then add the matching user details (other columns from the row in the users.csv file) to the events.

Pattern-based matching with field enrichment is, for example, useful in case you want to add user context to authentication logs.

Sample output from the incoming example data:

@timestampidactionsource_ipdepartmentaccess_levellocationtitle
2024-01-15T09:00:00.000ZADMIN-123login10.0.0.1ITadministratorHQSystem Administrator
2024-01-15T09:01:00.000Zdev-user-456code_push10.0.0.2EngineeringdeveloperRemoteSoftware Engineer
2024-01-15T09:02:00.000ZTEST_789test_run10.0.0.3QAtesterLabQA Engineer
2024-01-15T09:03:00.000Zsupport-001ticket_update10.0.0.4SupportagentOfficeSupport Specialist

After matching, the output combines original event fields with matched user details. Only events with matching patterns appear in output.