Array Query Functions

LogScale's array functions allow you to extract, create and manipulate items embedded in arrays, or to interpret arrays and nested arrays within events. In the Array Query Functions table, functions marked with array can be used with a flat array. Functions marked nested-array are designed for working with structured arrays.

Arrays can be parsed from incoming events using the splitString() or parseJson() functions.

For information on using arrays, see Array Syntax.

Table: Array Query Functions

FunctionTypeDefault ArgumentAvailabilityDescription
array:contains(array, value)array, data-manipulation, filterarray  Checks whether the given value matches any of the values of the array and excludes the event if no value matches.
array:eval(array, [asArray], function, [var])arrayarray  Evaluates the function argument on all values in the array under the array argument overwriting the array.
array:filter(array, [asArray], function, var)array, data-manipulation, filterarray  Drops entries from the input array using the given filtering function.
array:intersection(array, [as])aggregate, arrayarray  Determines the set intersection of array values over input events.
array:reduceAll(array, function, var)aggregate, array, data-manipulationarray  Computes a value from all events and array elements of the specified array.
array:reduceColumn(array, [as], function, var)aggregate, array, data-manipulationarray  Computes an aggregate value for each array element with the same index.
array:reduceRow(array, [as], function, var)arrayarray  Computes an aggregated value of an array on all events.
array:regex(array, [flags], regex)array, filter, regular-expressionarray  Checks whether the given pattern matches any of the values of the array and excludes the event from the search result.
array:union(array, [as])aggregate, array, data-manipulationarray  Determines the set union of array values over input events.
concatArray([as], field, [from], [prefix], [separator], [suffix], [to])array, data-manipulation, stringfield  Concatenates values of all fields with same name and an array suffix into a new field.
split([field], [strip])array, data-manipulationfield  Splits an event structure created by a JSON array into distinct events.
splitString([as], by, [field], [index])array, data-manipulation, regular-expression, stringfield  Splits a string by specifying a regular expression by which to split.

Using Array Query Functions

The following rules and recommendations apply to all the array query functions listed in the Array Query Functions table.

  • Array functions do not support non-consecutive items in an array.

    For example, when manipulating the array:

    logscale Syntax
    foo[0], foo[1], foo[3]

    The function will only run against:

    logscale Syntax
    foo[0], foo[1]

  • Array indexes start at zero; For example, foo[0].

  • When referring to the whole array, use foo[].

  • Arrays elements are identified using the array name with an [x] suffix.

    For example, having the array:

    logscale Syntax
    foo[0], foo[1]

    Adding another field:

    logscale Syntax
    foo[2]

    Results in the array:

    logscale Syntax
    foo[0],foo[1],foo[2]

    With no missing entries, array functions will run against them all.