105 lines
3.3 KiB
Markdown
105 lines
3.3 KiB
Markdown
|
---
|
||
|
|
id: time-min-max
|
||
|
|
title: "Timestamp Min/Max aggregators"
|
||
|
|
---
|
||
|
|
|
||
|
|
<!--
|
||
|
|
~ Licensed to the Apache Software Foundation (ASF) under one
|
||
|
|
~ or more contributor license agreements. See the NOTICE file
|
||
|
|
~ distributed with this work for additional information
|
||
|
|
~ regarding copyright ownership. The ASF licenses this file
|
||
|
|
~ to you under the Apache License, Version 2.0 (the
|
||
|
|
~ "License"); you may not use this file except in compliance
|
||
|
|
~ with the License. You may obtain a copy of the License at
|
||
|
|
~
|
||
|
|
~ http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
~
|
||
|
|
~ Unless required by applicable law or agreed to in writing,
|
||
|
|
~ software distributed under the License is distributed on an
|
||
|
|
~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
|
||
|
|
~ KIND, either express or implied. See the License for the
|
||
|
|
~ specific language governing permissions and limitations
|
||
|
|
~ under the License.
|
||
|
|
-->
|
||
|
|
|
||
|
|
|
||
|
|
To use this Apache Druid extension, make sure to [include](../../development/extensions.md#loading-extensions) `druid-time-min-max`.
|
||
|
|
|
||
|
|
These aggregators enable more precise calculation of min and max time of given events than `__time` column whose granularity is sparse, the same as query granularity.
|
||
|
|
To use this feature, a "timeMin" or "timeMax" aggregator must be included at indexing time.
|
||
|
|
They can apply to any columns that can be converted to timestamp, which include Long, DateTime, Timestamp, and String types.
|
||
|
|
|
||
|
|
For example, when a data set consists of timestamp, dimension, and metric value like followings.
|
||
|
|
|
||
|
|
```
|
||
|
|
2015-07-28T01:00:00.000Z A 1
|
||
|
|
2015-07-28T02:00:00.000Z A 1
|
||
|
|
2015-07-28T03:00:00.000Z A 1
|
||
|
|
2015-07-28T04:00:00.000Z B 1
|
||
|
|
2015-07-28T05:00:00.000Z A 1
|
||
|
|
2015-07-28T06:00:00.000Z B 1
|
||
|
|
2015-07-29T01:00:00.000Z C 1
|
||
|
|
2015-07-29T02:00:00.000Z C 1
|
||
|
|
2015-07-29T03:00:00.000Z A 1
|
||
|
|
2015-07-29T04:00:00.000Z A 1
|
||
|
|
```
|
||
|
|
|
||
|
|
At ingestion time, timeMin and timeMax aggregator can be included as other aggregators.
|
||
|
|
|
||
|
|
```json
|
||
|
|
{
|
||
|
|
"type": "timeMin",
|
||
|
|
"name": "tmin",
|
||
|
|
"fieldName": "<field_name, typically column specified in timestamp spec>"
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
```json
|
||
|
|
{
|
||
|
|
"type": "timeMax",
|
||
|
|
"name": "tmax",
|
||
|
|
"fieldName": "<field_name, typically column specified in timestamp spec>"
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
`name` is output name of aggregator and can be any string. `fieldName` is typically column specified in timestamp spec but can be any column that can be converted to timestamp.
|
||
|
|
|
||
|
|
To query for results, the same aggregators "timeMin" and "timeMax" is used.
|
||
|
|
|
||
|
|
```json
|
||
|
|
{
|
||
|
|
"queryType": "groupBy",
|
||
|
|
"dataSource": "timeMinMax",
|
||
|
|
"granularity": "DAY",
|
||
|
|
"dimensions": ["product"],
|
||
|
|
"aggregations": [
|
||
|
|
{
|
||
|
|
"type": "count",
|
||
|
|
"name": "count"
|
||
|
|
},
|
||
|
|
{
|
||
|
|
"type": "timeMin",
|
||
|
|
"name": "<output_name of timeMin>",
|
||
|
|
"fieldName": "tmin"
|
||
|
|
},
|
||
|
|
{
|
||
|
|
"type": "timeMax",
|
||
|
|
"name": "<output_name of timeMax>",
|
||
|
|
"fieldName": "tmax"
|
||
|
|
}
|
||
|
|
],
|
||
|
|
"intervals": [
|
||
|
|
"2010-01-01T00:00:00.000Z/2020-01-01T00:00:00.000Z"
|
||
|
|
]
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
Then, result has min and max of timestamp, which is finer than query granularity.
|
||
|
|
|
||
|
|
```
|
||
|
|
2015-07-28T00:00:00.000Z A 4 2015-07-28T01:00:00.000Z 2015-07-28T05:00:00.000Z
|
||
|
|
2015-07-28T00:00:00.000Z B 2 2015-07-28T04:00:00.000Z 2015-07-28T06:00:00.000Z
|
||
|
|
2015-07-29T00:00:00.000Z A 2 2015-07-29T03:00:00.000Z 2015-07-29T04:00:00.000Z
|
||
|
|
2015-07-29T00:00:00.000Z C 2 2015-07-29T01:00:00.000Z 2015-07-29T02:00:00.000Z
|
||
|
|
```
|