|
|
|
|
@ -1,23 +1,15 @@
|
|
|
|
|
---
|
|
|
|
|
title: InfluxDB key concepts
|
|
|
|
|
title: InfluxDB data elements
|
|
|
|
|
description: >
|
|
|
|
|
Concepts related to InfluxDB.
|
|
|
|
|
weight: 7
|
|
|
|
|
InfluxDB structures data using elements such as timestamps, field keys, field values, tags, etc.
|
|
|
|
|
weight: 102
|
|
|
|
|
menu:
|
|
|
|
|
v2_0_ref:
|
|
|
|
|
name: Key concepts
|
|
|
|
|
v2.0/tags: [key concepts]
|
|
|
|
|
parent: Key concepts
|
|
|
|
|
name: Data elements
|
|
|
|
|
v2.0/tags: [key concepts, schema]
|
|
|
|
|
---
|
|
|
|
|
|
|
|
|
|
Before working with InfluxDB 2.0, it's helpful to learn a few key concepts, including:
|
|
|
|
|
|
|
|
|
|
- [InfluxDB data elements](#influxdb-data-elements)
|
|
|
|
|
- [InfluxDB table structure](#influxdb-layout)
|
|
|
|
|
- [InfluxDB design principles](/v2.0/reference/design-principles)
|
|
|
|
|
<!--- [InfluxDB platform](/v2.0/reference/) -->
|
|
|
|
|
|
|
|
|
|
### InfluxDB data elements
|
|
|
|
|
|
|
|
|
|
InfluxDB 2.0 includes the following data elements:
|
|
|
|
|
|
|
|
|
|
- [timestamp](#timestamp)
|
|
|
|
|
@ -34,26 +26,7 @@ InfluxDB 2.0 includes the following data elements:
|
|
|
|
|
- [organization](#organization)
|
|
|
|
|
|
|
|
|
|
The [sample data](#sample-data) below is used to illustrate data elements concepts.
|
|
|
|
|
|
|
|
|
|
### InfluxDB table structure
|
|
|
|
|
|
|
|
|
|
InfluxDB 2.0 uses the following table structure to store data:
|
|
|
|
|
|
|
|
|
|
- **Annotation rows:** include the following rows: #group, #datatype, and #default.
|
|
|
|
|
- **Header row:** describes the data labels for each column in a row.
|
|
|
|
|
- **Data columns:** include the following columns: annotation, result, and table.
|
|
|
|
|
- **Data rows:** all rows that contain time series data. See [sample data](#sample-data) below.
|
|
|
|
|
|
|
|
|
|
For specifications on the InfluxDB 2.0 table structure, see [Tables](/v2.0/reference/annotated-csv/#tables).
|
|
|
|
|
|
|
|
|
|
**_Tip:_** To visualize your table structure in the InfluxDB user interface, click the **Data Explorer** icon
|
|
|
|
|
in the sidebar, create a query, click **Submit**, and then select **View Raw Data**.
|
|
|
|
|
|
|
|
|
|
### Sample data
|
|
|
|
|
|
|
|
|
|
The sample data below shows a number of bees counted by two scientists (`anderson` and `mullen`) in two locations (`klamath` and `portland`) from 12 AM to 6 AM on August 18, 2019. The sample data is stored in the bucket, `my_bucket`, and retained for the duration of the retention policy specified in the [bucket](#bucket).
|
|
|
|
|
|
|
|
|
|
**_Tip:_** Hover over purple terms to get acquainted with InfluxDB terminology and layout.
|
|
|
|
|
_Hover over highlighted terms to get acquainted with InfluxDB terminology and layout._
|
|
|
|
|
|
|
|
|
|
**bucket:** `my_bucket`
|
|
|
|
|
|
|
|
|
|
@ -64,27 +37,27 @@ The sample data below shows a number of bees counted by two scientists (`anderso
|
|
|
|
|
| 2019-08-18T00:06:00Z | census | klamath | anderson | bees | 28 |
|
|
|
|
|
| <span class="tooltip" data-tooltip-text="Timestamp">2019-08-18T00:06:00Z</span> | <span class="tooltip" data-tooltip-text="measurement"> census</span> | <span class ="tooltip" data-tooltip-text ="Tag value">portland</span> | <span class ="tooltip" data-tooltip-text ="Tag value">mullen</span> | <span class ="tooltip" data-tooltip-text ="Field key">ants</span> | <span class ="tooltip" data-tooltip-text ="Field value">32</span> |
|
|
|
|
|
|
|
|
|
|
#### Timestamp
|
|
|
|
|
## Timestamp
|
|
|
|
|
|
|
|
|
|
All data stored in InfluxDB has a `_time` column that stores timestamps. On disk, timestamps are stored in epoch nanosecond format. InfluxDB formats timestamps show the date and time in [RFC3339](https://www.ietf.org/rfc/rfc3339.txt) UTC associated with data. Timestamp precision is important when you write data.
|
|
|
|
|
|
|
|
|
|
#### Measurement
|
|
|
|
|
## Measurement
|
|
|
|
|
|
|
|
|
|
The `_measurement` column shows the name of the measurement `census`. Measurement names are strings. A measurement acts as a container for tags, fields, and timestamps. Use a measurement name that describes your data. The name `census` tells us that the field values record the number of `bees` and `ants`.
|
|
|
|
|
|
|
|
|
|
#### Fields
|
|
|
|
|
## Fields
|
|
|
|
|
|
|
|
|
|
A field includes a field key stored in the `_field` column and a field value stored in the `_value` column.
|
|
|
|
|
|
|
|
|
|
##### Field key
|
|
|
|
|
### Field key
|
|
|
|
|
|
|
|
|
|
A field key is a string that represents the name of the field. In the sample data above, `bees` and `ants` are field keys.
|
|
|
|
|
|
|
|
|
|
##### Field values
|
|
|
|
|
### Field values
|
|
|
|
|
|
|
|
|
|
A field value represents the value of an associated field. Field values can be strings, floats, integers, or booleans. The field values in the sample data show the number of `bees` at specified times: `23`, and `28` and the number of `ants` at a specified time: `30` and `32`.
|
|
|
|
|
|
|
|
|
|
##### Field sets
|
|
|
|
|
### Field sets
|
|
|
|
|
|
|
|
|
|
A field set is a collection of field key-value pairs associated with a timestamp. The sample data includes the following field sets:
|
|
|
|
|
|
|
|
|
|
@ -94,28 +67,28 @@ census bees=23i,ants=30i 1566086400000000000
|
|
|
|
|
census bees=28i,ants=32i 1566086760000000000
|
|
|
|
|
-----------------
|
|
|
|
|
Field set
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
{{% note %}}
|
|
|
|
|
**Fields aren't indexed:** Fields are required in InfluxDB data and are not indexed. Queries that filter field values must scan all field values to match query conditions. As a result, queries on tags > are more performant than queries on fields. **Store commonly queried metadata in tags.**
|
|
|
|
|
{{% /note %}}
|
|
|
|
|
|
|
|
|
|
#### Tags
|
|
|
|
|
## Tags
|
|
|
|
|
|
|
|
|
|
The columns in the sample data, `location` and `scientist`, are tags.
|
|
|
|
|
Tags include tag keys and tag values that are stored as strings and metadata.
|
|
|
|
|
|
|
|
|
|
##### Tag keys
|
|
|
|
|
### Tag keys
|
|
|
|
|
|
|
|
|
|
The tag keys in the sample data are `location` and `scientist`.
|
|
|
|
|
|
|
|
|
|
##### Tag values
|
|
|
|
|
### Tag values
|
|
|
|
|
|
|
|
|
|
The tag key `location` has two tag values: `klamath` and `portland`.
|
|
|
|
|
The tag key `scientist` also has two tag values: `anderson` and `mullen`.
|
|
|
|
|
|
|
|
|
|
##### Tag sets
|
|
|
|
|
### Tag sets
|
|
|
|
|
|
|
|
|
|
The collection of tag key-value pairs make up a tag set. The sample data includes the following four tag sets:
|
|
|
|
|
|
|
|
|
|
@ -135,10 +108,10 @@ Because tags are indexed, queries on tags are faster than queries on fields. Thi
|
|
|
|
|
|
|
|
|
|
If most of your queries focus on values in the fields, for example, a query to find when 23 bees were counted:
|
|
|
|
|
|
|
|
|
|
```bash
|
|
|
|
|
from(bucket: "bucket-name")
|
|
|
|
|
range(start: 2019-08-17T00:00:00Z, stop: 2019-08-19T00:00:00Z)
|
|
|
|
|
filter(fn: (r) => r._field == "bees" and r._value == 23)
|
|
|
|
|
```js
|
|
|
|
|
from(bucket: "bucket-name")
|
|
|
|
|
|> range(start: 2019-08-17T00:00:00Z, stop: 2019-08-19T00:00:00Z)
|
|
|
|
|
|> filter(fn: (r) => r._field == "bees" and r._value == 23)
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
InfluxDB scans every field value in the dataset for `bees` before the query returns a response. If our sample `census` data grew to millions of rows, to optimize your query, you could rearrange your [schema](/v2.0/reference/glossary/#schema) so the fields (`bees` and `ants`) becomes tags and the tags (`location` and `scientist`) become fields:
|
|
|
|
|
@ -159,7 +132,7 @@ InfluxDB scans every field value in the dataset for `bees` before the query retu
|
|
|
|
|
|
|
|
|
|
Now that `bees` and `ants` are tags, InfluxDB doesn't have to scan all `_field` and `_value` columns. This makes your queries faster.
|
|
|
|
|
|
|
|
|
|
#### Series
|
|
|
|
|
## Series
|
|
|
|
|
|
|
|
|
|
Now that you're familiar with measurements, field sets, and tag sets, it's time to discuss series keys and series. A **series key** is a collection of points that share a measurement, tag set, and field key. For example, the [sample data](#sample-data) includes two unique series keys:
|
|
|
|
|
|
|
|
|
|
@ -169,7 +142,7 @@ Now that you're familiar with measurements, field sets, and tag sets, it's time
|
|
|
|
|
| census | location=portland,scientist=mullen | ants |
|
|
|
|
|
|
|
|
|
|
A **series** includes timestamps and field values for a given series key. From the sample data, here's a **series key** and the corresponding **series**:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
```bash
|
|
|
|
|
# series key
|
|
|
|
|
census,location=klamath,scientist=anderson bees
|
|
|
|
|
@ -181,22 +154,22 @@ census,location=klamath,scientist=anderson bees
|
|
|
|
|
|
|
|
|
|
Understanding the concept of a series is essential when designing your [schema](v2.0/reference/glossary/#schema) and working with your data in InfluxDB.
|
|
|
|
|
|
|
|
|
|
#### Point
|
|
|
|
|
## Point
|
|
|
|
|
|
|
|
|
|
A **point** includes the series key, a field value, and a timestamp. For example, a single point from the [sample data](#sample-data) looks like this:
|
|
|
|
|
|
|
|
|
|
`2019-08-18T00:00:00Z census ants 30 portland mullen`
|
|
|
|
|
|
|
|
|
|
#### Bucket
|
|
|
|
|
## Bucket
|
|
|
|
|
|
|
|
|
|
All InfluxDB data is stored in a bucket. A **bucket** combines the concept of a database and a retention period (the duration of time that each data point persists). A bucket belongs to an organization. For more information about buckets, see [Manage buckets](https://v2.docs.influxdata.com/v2.0/organizations/buckets/).
|
|
|
|
|
|
|
|
|
|
#### Organization
|
|
|
|
|
## Organization
|
|
|
|
|
|
|
|
|
|
An InfluxDB **organization** is a workspace for a group of [users](/v2.0/users/). All [dashboards](/v2.0/visualize-data/dashboards/), [tasks](/v2.0/process-data/), buckets, and users belong to an organization. For more information about organizations, see [Manage organizations](https://v2.docs.influxdata.com/v2.0/organizations/).
|
|
|
|
|
|
|
|
|
|
If you're just starting out, we recommend taking a look at the following guides:
|
|
|
|
|
|
|
|
|
|
- [Getting Started](/influxdb/v0.10/introduction/getting_started/)
|
|
|
|
|
- [Getting Started](/influxdb/v0.10/introduction/getting_started/)
|
|
|
|
|
- [Writing Data](/influxdb/v0.10/guides/writing_data/)
|
|
|
|
|
- [Querying Data](/influxdb/v0.10/guides/querying_data/)
|
|
|
|
|
- [Querying Data](/influxdb/v0.10/guides/querying_data/)
|
kelseiv
GitHub