---
id: delta
title: delta Metrics Operator
sidebar_label: delta
description: Use the delta metrics operator to compute the backward difference at each data point, determining how much the metric changed from its previous value in the time series.
slug: /help/docs/metrics/metrics-operators/delta/
canonical: https://www.sumologic.com/help/docs/metrics/metrics-operators/delta/
---


The `delta` operator computes the backward difference at each data point in the time series to determine how much the metric has changed from its last value in the series.

The `delta` operator updates the `metric` dimension, if present, to `delta($metric)`. If the original time series does not have a `metric` dimension, it creates `metric=delta` dimension. Other dimensions remain unaffected.

## Syntax

```sql
delta [increasing | decreasing | counter]
```

When deciding which mode you should use, here are some guidelines:
* You need to get the difference of a counter - use `delta counter`.
* You need to get the difference of a non-counter metric - use `delta`.

You can also use the `increasing` or `decreasing` option to make `delta` consider only pairs of consecutive points where the second point is greater (`increasing` option) or less (`decreasing` option) than the first point. However, these options are mostly kept for backward compatibility and so their usage is not recommended.

## Examples

### Difference in a metric value from previous point

This query returns a time series that reflects the difference in the `Net_InBytes`  metric for the `eth0` interface  between a charted value and the one preceding it.

```sql
metric=Net_InBytes Interface=eth0 | delta
```

### Positive difference in a metric over time

This query returns a time series that reflects the difference in the `elasticsearch_jvm_mem_heap_used_in_bytes`  metric between a charted value and the one preceding it, only considering pairs of consecutive points where the second point is greater than the first point.

```sql
metric=elasticsearch_jvm_mem_heap_used_in_bytes | delta increasing
```

### Difference in a counter over time

This query returns a time series that reflects the difference in the `apiserver_request_total` counter between a charted value and the one preceding it, accounting for counter resets.

```sql
metric=apiserver_request_total | delta counter
```