--- title: InfluxDB data elements description: InfluxDB structures data using elements such as timestamps, field keys, field values, tags, etc. url: https://docs.influxdata.com/influxdb/v2/reference/key-concepts/data-elements/ estimated_tokens: 2102 product: InfluxDB OSS v2 version: v2 publisher: InfluxData canonical: https://docs.influxdata.com/influxdb/v2/reference/key-concepts/data-elements/ date: '2025-04-02T15:54:32-06:00' lastmod: '2025-04-02T15:54:32-06:00' --- This page documents an earlier version of InfluxDB OSS.[InfluxDB 3 Core](/influxdb3/core/) is the latest stable version. #### API token hashing is enabled by default in InfluxDB OSS 2.9.0 Stronger token security: tokens are stored as hashes on disk, so a copy of the database file doesn’t expose usable tokens. Existing tokens are hashed on first startup and the original strings can’t be recovered afterward — **capture any plaintext tokens you still need before you upgrade**. For more information, see [Token hashing](/influxdb/v2/admin/tokens/#token-hashing). InfluxDB 2.9 includes the following data elements: * [Timestamp](#timestamp) * [Measurement](#measurement) * [Fields](#fields) * [Field key](#field-key) * [Field value](#field-value) * [Field set](#field-set) * [Tags](#tags) * [Tag key](#tag-key) * [Tag value](#tag-value) * [Tag set](#tag-set) * [Series](#series) * [Point](#point) * [Bucket](#bucket) * [Organization](#organization) The following sample data represents time series records stored in InfluxDB and is used to illustrate data elements concepts.*Hover over highlighted terms to get acquainted with InfluxDB terminology and layout.*[]() **bucket:** `my_bucket` | \_time |\_measurement|location|scientist|\_field|\_value| |--------------------|-------------|--------|---------|-------|-------| |2019-08-18T00:00:00Z| census |klamath |anderson | bees | 23 | |2019-08-18T00:00:00Z| census |portland| mullen | ants | 30 | |2019-08-18T00:06:00Z| census |klamath |anderson | bees | 28 | |2019-08-18T00:06:00Z| census |portland| mullen | ants | 32 | ## 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](/influxdb/v2/reference/glossary/#rfc3339-timestamp) UTC associated with data. Timestamp precision is important when you write data. ## 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 A field includes a field key stored in the `_field` column and a field value stored in the `_value` column. ### Field key A field key is a string that represents the name of the field. In the preceding [sample data](#sample-data), `bees` and `ants` are field keys. ### Field value 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 set A field set is a collection of field key-value pairs associated with a timestamp. The [sample data](#sample-data) includes the following field sets: ```text census bees=23i,ants=30i 1566086400000000000 census bees=28i,ants=32i 1566086760000000000 ----------------- Field set ``` #### 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. See how to [use tags and fields](/influxdb/v2/write-data/best-practices/schema-design/#use-tags-and-fields) to make your schema easier to query. ## 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 key The tag keys in the sample data are `location` and `scientist`.*For information about tag key requirements, see [Line protocol – Tag set](/influxdb/v2/reference/syntax/line-protocol/#tag-set).* ### Tag value The tag key `location` has two tag values: `klamath` and `portland`. The tag key `scientist` also has two tag values: `anderson` and `mullen`.*For information about tag value requirements, see [Line protocol – Tag set](/influxdb/v2/reference/syntax/line-protocol/#tag-set).* ### Tag set The collection of tag key-value pairs make up a tag set. The sample data includes the following four tag sets: ```bash location = klamath, scientist = anderson location = portland, scientist = anderson location = klamath, scientist = mullen location = portland, scientist = mullen ``` #### Tags are indexed Tags are optional. You don’t need tags in your data structure, but it’s typically a good idea to include them. Because InfluxDB indexes tags, the query engine doesn’t need to scan every record in a bucket to locate a tag value. See how to [use tags to improve query performance](/influxdb/v2/write-data/best-practices/schema-design/#use-tags-to-improve-query-performance). ### Why your schema matters How you structure measurements, fields, and tags in your data can make queries easier to write and more performant. Good [schema design](/influxdb/v2/write-data/best-practices/schema-design) can prevent [high series cardinality](/influxdb/v2/write-data/best-practices/resolve-high-cardinality/), resulting in better performing queries. ## Series Now that you’re familiar with measurements, field sets, and tag sets, it’s time to discuss series keys and series. In InfluxDB OSS (TSM), a [series key](/influxdb/v2/reference/glossary/#series-key) is a unique combination of measurement and tag set. For example, the [sample data](#sample-data) includes two unique series keys: |measurement| tag set | |-----------|-----------------------------------| | census |location=klamath,scientist=anderson| | census |location=portland,scientist=mullen | A *series* includes timestamps and field values for a given series key–for example, the sample data contains the following series key and corresponding series: ### Sample data series * census,location=klamath,scientist=anderson * 2019-08-18T00:00:00Z 23 * 2019-08-18T00:06:00Z 28 Understanding the concept of a series is essential when [designing your schema](/influxdb/v2/write-data/best-practices/schema-design/) and working with your data in InfluxDB. ## Point A **point** includes the series key, a field value, and a timestamp–for example, a single point from the [sample data](#sample-data): `2019-08-18T00:00:00Z census ants 30 portland mullen` ## 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](/influxdb/v2/admin/buckets/). ## Organization An InfluxDB **organization** is a workspace for a group of [users](/influxdb/v2/admin/users/). All [dashboards](/influxdb/v2/visualize-data/dashboards/), [tasks](/influxdb/v2/process-data/), buckets, and users belong to an organization. For more information about organizations, see [Manage organizations](/influxdb/v2/admin/organizations/). If you’re new to using InfluxDB, see how to [get started](/influxdb/v2/get-started) writing and querying data. For an overview of how these elements interconnect within InfluxDB’s data model, watch the following video: #### Related * [Building Blocks of the InfluxDB Data Model](/resources/videos/data-model-building-blocks/) * [Resolve high series cardinality](/influxdb/v2/write-data/best-practices/resolve-high-cardinality/) * [InfluxDB schema design](/influxdb/v2/write-data/best-practices/schema-design/) [key concepts](/influxdb/v2/tags/key-concepts/)[schema](/influxdb/v2/tags/schema/) | _time | _measurement | location | scientist | _field | _value | | --- | --- | --- | --- | --- | --- | | _time | _measurement | location | scientist | _field | _value | | 2019-08-18T00:00:00Z | census | klamath | anderson | bees | 23 | | 2019-08-18T00:00:00Z | census | portland | mullen | ants | 30 | | 2019-08-18T00:06:00Z | census | klamath | anderson | bees | 28 | | 2019-08-18T00:06:00Z | census | portland | mullen | ants | 32 | | measurement | tag set | | --- | --- | | measurement | tag set | | census | location=klamath,scientist=anderson | | census | location=portland,scientist=mullen |