PromQL operators [promql-operators]

These operators are based on the Prometheus operators. Refer to the Prometheus documentation for the full semantics, and note any {{es}}-specific differences called out per operator.

Operators overview [promql-operators-overview]

Arithmetic operators

Binary operators that perform arithmetic between scalars and instant vectors.

::::{dropdown} Arithmetic operator list :open: :::{include} _snippets/generated/x-pack-esql/operators/lists/arithmetic-overview.md ::: ::::

Comparison operators

Binary operators that filter instant vectors or, with the bool modifier, return 0 or 1.

::::{dropdown} Comparison operator list :open: :::{include} _snippets/generated/x-pack-esql/operators/lists/comparison-overview.md ::: ::::

Logical/set operators

Binary operators that combine two instant vectors by matching their label sets.

::::{dropdown} Logical/set operator list :open: :::{include} _snippets/generated/x-pack-esql/operators/lists/logical-set-overview.md ::: ::::

Unary operators

Operators that apply to a single instant vector or scalar.

::::{dropdown} Unary operator list :open: :::{include} _snippets/generated/x-pack-esql/operators/lists/unary-overview.md ::: ::::

Label matching operators

Operators used inside instant vector selectors ({...}) to match series by label.

::::{dropdown} Label matching operator list :open: :::{include} _snippets/generated/x-pack-esql/operators/lists/label-matching-overview.md ::: ::::

Binary operator precedence [promql-operators-precedence]

PromQL follows the same binary operator precedence as Prometheus. The following list orders operators from highest to lowest precedence; operators listed together share the same precedence level:

1. ^
2. *, /, %, atan2
3. +, -
4. ==, !=, <=, <, >=, >
5. and, unless
6. or

^ is right-associative; all other binary operators are left-associative. Use parentheses to override the default precedence.

::::{note} atan2, and, and unless are listed here for completeness, but are not evaluated yet in {{es}}. See Not yet supported and PromQL limitations. ::::

Vector matching [promql-operators-vector-matching]

When a binary operator is applied between two instant vectors, PromQL matches samples that have identical label sets (one-to-one matching). Prometheus provides modifiers that change which labels are considered (on(...) and ignoring(...)) and that enable many-to-one and one-to-many matching (group_left and group_right).

{{es}} does not support the on(...), ignoring(...), group_left, or group_right vector matching modifiers yet. Using them returns a client error (4xx). See PromQL limitations.

The bool modifier [promql-operators-bool-modifier]

By default, a comparison operator between two instant vectors acts as a filter: samples that do not satisfy the comparison are dropped, and matching samples keep their original values. Appending the bool modifier changes this behavior so that the comparison returns 0 for false and 1 for true, and keeps every sample. The bool modifier is required when comparing two scalars.

Example

requests_total > bool 256

Aggregation operators [promql-operators-aggregation]

Prometheus documents aggregation operators (such as sum, avg, min, max, and count) on its operators page. In {{es}} PromQL, these are documented as aggregation functions.

Not yet supported [promql-operators-not-supported]

The following Prometheus operators are not supported in {{es}} PromQL yet:

:::{include} _snippets/generated/x-pack-esql/operators/not-supported.md :::