# Summarize Operator

## Overview

Aggregate findings with `summarize`.

```kusto
| summarize [[<dest>=]aggregation[, ...]] by [<dest>=]<expression>[, ...] 
```

Many aggregations are supported, including:

* [`agg.avg()`](../../functions/aggregation#agg.avg)
* [`agg.count()`](../../functions/aggregation#agg.count)
* [`agg.count_distinct()`](../../functions/aggregation#agg.count_distinct)
* [`agg.make_set()`](../../functions/aggregation#agg.make_set)
* [`agg.max()`](../../functions/aggregation#agg.max)
* [`agg.min()`](../../functions/aggregation#agg.min)
* [`agg.percentile_cont()`](../../functions/aggregation#agg.percentile_cont)
* [`agg.stddev()`](../../functions/aggregation#agg.stddev)
* [`agg.sum()`](../../functions/aggregation#agg.sum)
* [`agg.take_any()`](../../functions/aggregation#agg.take_any)

See a full list of available aggregations on [Aggregation Functions](../functions/aggregation).

## Examples

### Count

The following query displays the count of all events in the last day stored in field `num_connections`:

```kusto
panther_logs.public.aws_alb
| where p_event_time > time.ago(1d)
| summarize num_connections=agg.count()
```

| num\_connections |
| ---------------- |
| 993              |

### Group count by single field

The following query counts the number of connections for each `clientIp` and orders results with the largest number of connections first:

```kusto
panther_logs.public.aws_alb
| where p_event_time > time.ago(1d)
| summarize num_connections=agg.count() by clientIp
| sort num_connections
```

| clientIp     | num\_connections |
| ------------ | ---------------- |
| 192.167.7.55 | 979              |
| 10.145.4.26  | 130              |
| 10.99.231.15 | 31               |
| ...          |                  |

### Group count by multiple fields

The following query displays `num_connections` grouped by both the `clientIp` and `clientPort` fields:

```kusto
panther_logs.public.aws_alb
| where p_event_time > time.ago(1d)
| summarize num_connections=agg.count() by clientIp, clientPort
| sort num_connections
```

| clientIp     | clientPort | num\_connections |
| ------------ | ---------- | ---------------- |
| 192.167.7.55 | 50160      | 7                |
| 10.145.4.26  | 63335      | 5                |
| 10.145.4.26  | 60845      | 4                |
| 192.167.7.55 | 52138      | 4                |
| 10.99.231.15 | 58704      | 3                |
| …            |            |                  |

### Group count by arbitrary expressions

```kusto
panther_logs.public.aws_alb
| where p_event_time > time.ago(1d)
| summarize num_connections=agg.count() by isOK = elbStatusCode == 200
| sort num_connections
```

| isOK  | num\_connections |
| ----- | ---------------- |
| true  | 1114             |
| false | 324              |

### Count distinct

The query below stores the distinct number of `clientIp`s in `num_distinct_clients`:

```kusto
panther_logs.public.aws_alb
| where p_event_time > time.ago(1d)
| summarize num_distinct_clients=agg.count_distinct(clientIp)
```

| num\_distinct\_clients |
| ---------------------- |
| 121                    |

### Refer to an aggregation later

You can refer to an aggregation in a subsequent query expression:

```kusto
panther_logs.public.aws_alb
| where p_event_time > time.ago(1d)
| summarize num_connections=agg.count() by clientIp, clientPort
| where num_connections >= 5
```

| clientIp     | clientPort | num\_connections |
| ------------ | ---------- | ---------------- |
| 192.167.7.55 | 50160      | 7                |
| 10.145.4.26  | 63335      | 5                |
| ...          |            |                  |

### Summarize by field (without aggregation)

The query below displays each unique `userAgent`:

```kusto
panther_logs.public.aws_alb
| where p_event_time > time.ago(1d)
| summarize by userAgent
```

| userAgent                                                                                                                              |
| -------------------------------------------------------------------------------------------------------------------------------------- |
| Mozilla/5.0 (X11; Linux x86\_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 Safari/537.36                              |
| curl/8.1.2                                                                                                                             |
| Mozilla/5.0 (Linux; Android 7.0; LG-H918 Build/NRD90M) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Mobile Safari/537.36 |
| …                                                                                                                                      |
