From 3e08da9d61a4d4d53281bfc04f6955aba3a5e753 Mon Sep 17 00:00:00 2001 From: Jason Stirnaman Date: Tue, 15 Apr 2025 10:14:28 -0500 Subject: [PATCH] chore(reference): Initial commit of shared glossary copied from Cloud Dedicated --- .../shared/influxdb3-reference/glossary.md | 1149 +++++++++++++++++ 1 file changed, 1149 insertions(+) create mode 100644 content/shared/influxdb3-reference/glossary.md diff --git a/content/shared/influxdb3-reference/glossary.md b/content/shared/influxdb3-reference/glossary.md new file mode 100644 index 000000000..35c717f18 --- /dev/null +++ b/content/shared/influxdb3-reference/glossary.md @@ -0,0 +1,1149 @@ +--- +title: Glossary +description: > + Terms related to InfluxData products and platforms. +weight: 109 +menu: + influxdb3_cloud_dedicated: + parent: Reference +influxdb3/cloud-dedicated/tags: [glossary] +--- + +[A](#a) | [B](#b) | [C](#c) | [D](#d) | [E](#e) | [F](#f) | [G](#g) | [H](#h) | [I](#i) | [J](#j) | [K](#k) | [L](#l) | [M](#m) | [N](#n) | [O](#o) | [P](#p) | [Q](#q) | [R](#r) | [S](#s) | [T](#t) | [U](#u) | [V](#v) | [W](#w) | X | Y | Z + +## A + +### abstract syntax tree (AST) + +Tree representation of source code that shows the structure, content, and rules +of programming statements and discards additional syntax elements. +The tree is hierarchical, with elements of program statements broken down into their parts. + +For more information about AST design, see [Abstract Syntax Tree on Wikipedia](https://en.wikipedia.org/wiki/Abstract_syntax_tree). + +### agent + +A background process started by (or on behalf of) a user that typically requires user input. + +[Telegraf](/telegraf/v1/) is an agent that requires user input +(a configuration file) to gather metrics from declared input plugins and sends +metrics to declared output plugins, based on the plugins enabled for a configuration. + +Related entries: +[input plugin](#input-plugin), +[output plugin](#output-plugin), +[daemon](#daemon) + +### aggregator plugin + +Receives metrics from input plugins, creates aggregate metrics, and then passes aggregate metrics to configured output plugins. + +Related entries: +[input plugin](#input-plugin), +[output plugin](#output-plugin), +[processor plugin](#processor-plugin) + +### aggregate + +A function that returns an aggregated value across a set of points. +For a list of available aggregation functions, +see [SQL aggregate functions](/influxdb3/cloud-dedicated/reference/sql/functions/aggregate/). + + + +Related entries: +[function](#function), +[selector](#selector) + +### API + +Application programming interface that facilitates and standardizes communication +between two or more computer programs. + +### argument + +A value passed to a function or command that determines how the process operates. + +Related entries: +[parameter](#parameter) + +## B + +### batch + +A collection of points in line protocol format, separated by newlines (`0x0A`). +Submitting a batch of points using a single HTTP request to the write endpoints +drastically increases performance by reducing the HTTP overhead. +InfluxData typically recommends batch sizes of 5,000-10,000 points. +In some use cases, performance may improve with significantly smaller or larger batches. + +Related entries: +[line protocol](#line-protocol-lp), +[point](#point) + +### batch size + +The number of lines or individual data points in a line protocol batch. +The Telegraf agent sends metrics to output plugins in batches rather than individually. +Batch size controls the size of each write batch that Telegraf sends to the output plugins. + +Related entries: +[output plugin](#output-plugin) + +### bin + +In a cumulative histogram, a bin includes all data points less than or equal to a specified upper bound. +In a normal histogram, a bin includes all data points between the upper and lower bounds. +Histogram bins are also sometimes referred to as "buckets." + +### boolean + +A data type with two possible values: true or false. +By convention, you can express `true` as the integer `1` and false as the integer `0` (zero). + +### bucket + +"Bucket" is the term used in InfluxDB 2.x and _InfluxDB Cloud Serverless_ to refer +to a named location where time series data is stored. +Bucket is synonymous with "database" when using InfluxDB Cloud Dedicated. + +Related entries: +[database](#database) + +## C + +### CSV + +Comma-separated values (CSV) delimits text between commas to separate values. +A CSV file stores tabular data (numbers and text) in plain text. +Each line of the file is a data row. +Each row consists of one or more columns, separated by commas. +CSV file format is not fully standardized. + +### cardinality + +Cardinality is the number of unique values in a set. +Series cardinality is the number of unique [series](#series) in a database as a whole. +With the InfluxDB 3 storage engine, high series cardinality _does not_ affect performance. + +### cluster + +A collection of servers or processes that work together as a single unit. +An InfluxDB Cloud Dedicated cluster is a collection of InfluxDB servers dedicated +to the workload of a single customer. + +### collect + +Collect and write time series data to InfluxDB using line protocol, Telegraf, +the InfluxDB v1 and v2 HTTP APIs, v1 and v2 `influx` command line interface (CLI), +and InfluxDB client libraries. + +### collection interval + +The default global interval for collecting data from each Telegraf input plugin. +The collection interval can be overridden by each individual input plugin's configuration. + +Related entries: +[input plugin](#input-plugin) + +### collection jitter + +Collection jitter prevents every input plugin from collecting metrics simultaneously, +which can have a measurable effect on the system. +For each collection interval, every Telegraf input plugin will sleep for a random +time between zero and the collection jitter before collecting the metrics. + +Related entries: +[collection interval](#collection-interval), +[input plugin](#input-plugin) + +### column + +InfluxDB data is stored in tables within rows and columns. +Columns store tag sets and fields sets, and time values. +The only required column is _time_, which stores timestamps and is included +in all InfluxDB tables. + +### common log format (CLF) + +A standardized text file format used by the InfluxDB server to create log +entries when generating server log files. + +### compaction + +Compressing time series data to optimize disk usage. + +### continuous query (CQ) + +Continuous queries are a feature of InfluxDB 1.x used to regularly downsample +or process time series data. + +## D + +### daemon + +A background process that runs without user input. + +### dashboard + +A collection of data visualizations used to query and display time series data. +There a many tools designed specifically to create dashboards including +[Grafana](https://grafana.com), [Apache Superset](https://superset.apache.org/), +[Tableau](https://www.tableau.com/), and others. + + + +### data model + +A data model organizes elements of data and standardizes how they relate to one +another and to properties of the real world entities. + +For information about the InfluxDB data model, see +[InfluxDB data organization](/influxdb3/cloud-dedicated/get-started/#data-organization) + +### data service + +Stores time series data and handles writes and queries. + +### data source + +A source of data that InfluxDB collects or queries data from. + +Related entries: +[database](#database) + +### data type + +A data type is defined by the values it can take, the programming language used, +or the operations that can be performed on it. + +InfluxDB supports the following data types: + +- string +- boolean +- float (64-bit) +- integer (64-bit) +- unsigned integer (64-bit) +- time + +For more information about different data types, see: + +- [line protocol](/influxdb/v2/reference/syntax/line-protocol/#data-types-and-format) +- [InfluxQL](/influxdb/v1/query_language/spec/#literals) +- [InfluxDB](/influxdb/v2/reference/syntax/line-protocol/#data-types-and-format) + +#### database + +A named location where time series data is stored. + +In InfluxDB 1.x, a database represented a logical container for users, retention +policies, continuous queries, and time series data. +In InfluxDB 2.x, the equivalent of this concept is an InfluxDB [bucket](#bucket). + +Related entries: +[bucket](#bucket), +[retention policy](#retention-policy-rp) + +### date-time + +InfluxDB stores the date-time format for each data point in a timestamp with +nanosecond-precision Unix time. +Specifying a timestamp is optional. +If a timestamp isn't specified for a data point, InfluxDB uses the server’s +local nanosecond timestamp in UTC. + +### downsample + +Aggregating high resolution data into lower resolution data to preserve disk space. + +### duration + +A data type that represents a duration of time--for example, `1s`, `1m`, `1h`, `1d`. +Retention periods are set using durations. + +Related entries: +[retention period](#retention-period) + +## E + +### event + +Metrics gathered at irregular time intervals. + +### expression + +A combination of one or more constants, variables, operators, and functions. + +In the following SQL example, `now() - INTERVAL '7 days'` is an expression that calculates the difference between the `now()` function expression and the duration represented by `INTERVAL '7 days`: + +```sql +SELECT * +FROM home +WHERE + time >= now() - INTERVAL '7 days' +``` + +## F + +### field + +A key-value pair in InfluxDB's data structure that records a data value. +Generally, field values change over time. +Fields are required in InfluxDB's data structure. + +Related entries: +[field key](#field-key), +[field set](#field-set), +[field value](#field-value), +[tag](#tag) + +### field key + +The key of the key-value pair. +Field keys are strings. + +Related entries: +[field](#field), +[field set](#field-set), +[field value](#field-value), +[tag key](#tag-key) + +### field set + +The collection of field key-value pairs. + +Related entries: +[field](#field), +[field key](#field-key), +[field value](#field-value), +[point](#point) + +### field value + +The value of a key-value pair. +Field values are the actual data; they can be strings, floats, integers, unsigned integers or booleans. +A field value is always associated with a timestamp. + +Related entries: +[field](#field), +[field key](#field-key), +[field set](#field-set), +[tag set](#tag-set), +[tag value](#tag-value), +[timestamp](#timestamp) + +### file block + +A file block is a fixed-length chunk of data read into memory when requested by an application. + +### float + +A real number written with a decimal point dividing the integer and fractional parts (`1.0`, `3.14`, `-20.1`). +InfluxDB supports 64-bit float values. + +### flush interval + +The global interval for flushing data from each Telegraf output plugin to its destination. +This value should not be set lower than the collection interval. + +Related entries: +[collection interval](#collection-interval), +[flush jitter](#flush-jitter), +[output plugin](#output-plugin) + +### flush jitter + +Flush jitter prevents every Telegraf output plugin from sending writes +simultaneously, which can overwhelm some data sinks. +Each flush interval, every Telegraf output plugin sleeps for a random time +between zero and the flush jitter before emitting metrics. +Flush jitter smooths out write spikes when running a large number of Telegraf instances. + +Related entries: +[flush interval](#flush-interval), +[output plugin](#output-plugin) + +### function + +A function is an operation that performs a specific task. +Functions take input, operate on that input, and then return output. +For a complete list of available SQL functions, see +[SQL functions](/influxdb3/cloud-dedicated/reference/sql/functions/). + + + +Related entries: +[aggregate](#aggregate), +[selector](#selector) + +## G + +### gzip + +gzip is a type of data compression that compress chunks of data, which is +restored by unzipping compressed gzip files. +The gzip file extension is `.gz`. + +## H + +### histogram + +A visual representation of statistical information that uses rectangles to show +the frequency of data items in successive, equal intervals or bins. + +## I + +### identifier + +Identifiers are tokens that refer to specific database objects such as database +names, field keys, measurement names, tag keys, etc. + +Related entries: +[database](#database), +[field key](#field-key), +[measurement](#measurement), +[tag key](#tag-key) + +### influx + +`influx` is a command line interface (CLI) that interacts with the InfluxDB v1.x and v2.x server. + +### influxctl + +[`influxctl`](/influxdb3/cloud-dedicated/reference/cli/influxctl/) is a CLI that +performs [administrative tasks](/influxdb3/cloud-dedicated/admin/) for an +InfluxDB Cloud dedicated cluster. + +### influxd + +`influxd` is the InfluxDB OSS v1.x and v2.x daemon that runs the InfluxDB server +and other required processes. + +### InfluxDB + +An open source time series database (TSDB) developed by InfluxData, optimized for fast, high-availability storage and retrieval of +time series data in fields such as operations monitoring, application metrics, +Internet of Things sensor data, and real-time analytics. + +### InfluxQL + +The SQL-like query language used to query data in InfluxDB. + +### input plugin + +Telegraf input plugins actively gather metrics and deliver them to the core agent, +where aggregator, processor, and output plugins can operate on the metrics. +To activate an input plugin, enable and configure it in the +Telegraf configuration file. + +Related entries: +[aggregator plugin](#aggregator-plugin), +[collection interval](#collection-interval), +[output plugin](#output-plugin), +[processor plugin](#processor-plugin) + +### instance + +An entity comprising data on a server (or virtual server in cloud computing). + + +### integer + +A whole number that is positive, negative, or zero (`0`, `-5`, `143`). +InfluxDB supports 64-bit integers (minimum: `-9223372036854775808`, maximum: `9223372036854775807`). + +Related entries: +[unsigned integer](#unsigned-integer) + +### IOx + +The IOx storage engine (InfluxDB 3 storage engine) is a real-time, columnar +database optimized for time series data built in Rust on top of +[Apache Arrow](https://arrow.apache.org/) and +[DataFusion](https://arrow.apache.org/datafusion/user-guide/introduction.html). +IOx replaces the [TSM (Time Structured Merge tree)](#tsm-time-structured-merge-tree) storage engine. + +## J + +### JWT + +Typically, JSON web tokens (JWT) are used to authenticate users between an +identity provider and a service provider. +A server can generate a JWT to assert any business processes. +For example, an "admin" token sent to a client can prove the client is logged in as admin. +Tokens are signed by one party's private key (typically, the server). +Private keys are used by both parties to verify that a token is legitimate. + +JWT uses an open standard specified in [RFC 7519](https://tools.ietf.org/html/rfc7519). + +### Jaeger + +Open source tracing used in distributed systems to monitor and troubleshoot transactions. + +### JSON + +JavaScript Object Notation (JSON) is an open-standard file format that uses +human-readable text to transmit data objects consisting of attribute–value pairs +and array data types. + +## K + +### keyword + +A keyword is reserved by a program because it has special meaning. +Every programming language has a set of keywords (reserved names) that cannot be used as identifiers--for example, +you can't use `SELECT` (an SQL keyword) as a variable name in an SQL query. + +See keyword lists: + +- [SQL keywords](/influxdb3/cloud-dedicated/reference/sql/#keywords) +- [InfluxQL keywords](/influxdb3/cloud-dedicated/reference/influxql/#keywords) + +## L + +### literal + +A literal is value in an expression, a number, character, string, function, record, or array. +Literal values are interpreted as defined. + +### load balancing + +Improves workload distribution across multiple computing resources in a network. +Load balancing optimizes resource use, maximizes throughput, minimizes response +time, and avoids overloading a single resource. +Using multiple components with load balancing instead of a single component may +increase reliability and availability. +If requests to any server in a network increase, requests are forwarded to +another server with more capacity. +Load balancing can also refer to the communications channels themselves. + +### logs + +Logs record information. +Event logs describe system events and activity that help to describe and diagnose problems. +Transaction logs describe changes to stored data that help recover data if a +database crashes or other errors occur. + +### line protocol (LP) + +The text based format for writing points to InfluxDB. +See [line protocol](/influxdb3/cloud-dedicated/reference/syntax/line-protocol/). + +## M + +### measurement + +The part of InfluxDB's data structure that describes the data stored in associated fields. +Measurements are strings. + +Related entries: +[field](#field), [series](#series) + +### metric + +Data tracked over time. + +### metric buffer + +The metric buffer caches individual metrics when writes are failing for an Telegraf output plugin. +Telegraf will attempt to flush the buffer upon a successful write to the output. +The oldest metrics are dropped first when this buffer fills. + +Related entries: +[output plugin](#output-plugin) + +### missing values + +Denoted by a null value. +Identifies missing information, which may be useful to include in an error message. + +## N + +### node + +An independent process or server in a cluster. + +Related entries: +[cluster](#cluster), +[server](#server) + +### now + +The local server's nanosecond timestamp. + +### null + +A data type that represents a missing or unknown value. +Denoted by the `null` value. +Values of [tags](#tag) and [fields](#field) may be `null`, but timestamp values are never `null`. + +## O + +### operator + +A symbol that usually represents an action or process. +For example: `+`, `-`, `>`. + +Related entries: +[operand](#operand) + +### operand + +The object or value on either side of an [operator](#operator). + +Related entries: +[operator](#operator) + +### organization + +An InfluxDB v2 concept that describes workspace for a group of users. +All InfluxDB v2 dashboards, tasks, buckets, members, and so on, belong to an organization. +Organizations are not part of InfluxDB Cloud Dedicated. + +### owner + +A type of role for a user. +Owners have read/write permissions. +Users can have owner roles for databases and other resources. + +Role permissions are separate from API token permissions. For additional +information on API tokens, see [token](#token). + +### output plugin + +Telegraf output plugins deliver metrics to their configured destination. +To activate an output plugin, enable and configure the plugin in Telegraf's configuration file. + +Related entries: +[aggregator plugin](#aggregator-plugin), +[flush interval](#flush-interval), +[input plugin](#input-plugin), +[processor plugin](#processor-plugin) + +## P + +### parameter + +A key-value pair used to pass information to a function that determines how the +function operates. + +Related entries: +[argument](#argument) + +### pipe + +Method for passing information from one process to another. +For example, an output parameter from one process is input to another process. +Information passed through a pipe is retained until the receiving process reads the information. + +### point + +Single data record identified by its _measurement_, _tag keys_, _tag values_, +_field key_, and _timestamp_. + +In a [series](#series), each point has a unique timestamp. +If you write a point to a series with a timestamp that matches an existing point, +the field set becomes a union of the old and new field set, where any ties go to +the new field set. + +Related entries: +[measurement](#measurement), +[tag set](#tag-set), +[field set](#field-set), +[timestamp](#timestamp) + +### primary key + +With the InfluxDB IOx storage engine, the primary key is the list of columns +used to uniquely identify each row in a table. +Rows are uniquely identified by their timestamp and tag set. +A row's primary key tag set does not include tags with null values. + +### precision + +The precision configuration setting determines the timestamp precision retained +for input data points. +All incoming timestamps are truncated to the specified precision. +Valid precisions are `ns`, `us` or `µs`, `ms`, and `s`. + +In Telegraf, truncated timestamps are padded with zeros to create a nanosecond timestamp. +Telegraf output plugins emit timestamps in nanoseconds. +For example, if the precision is set to `ms`, the nanosecond epoch timestamp `1480000000123456789` is truncated to `1480000000123` in millisecond precision and padded with zeroes to make a new, less precise nanosecond timestamp of `1480000000123000000`. +Telegraf output plugins do not alter the timestamp further. +The precision setting is ignored for service input plugins. + +Related entries: +[aggregator plugin](#aggregator-plugin), +[input plugin](#input-plugin), +[output plugin](#output-plugin), +[processor plugin](#processor-plugin), +[service input plugin](#service-input-plugin) + +### predicate expression + +A predicate expression compares two values and returns `true` or `false` based on +the relationship between the two values. +A predicate expression is comprised of a left operand, a comparison operator, and a right operand. + +### process + +A set of predetermined rules. +A process can refer to instructions being executed by the computer processor or +refer to the act of manipulating data. + +### processor plugin + +Telegraf processor plugins transform, decorate, and filter metrics collected by +input plugins, passing the transformed metrics to the output plugins. + +Related entries: +[aggregator plugin](#aggregator-plugin), +[input plugin](#input-plugin), +[output plugin](#output-plugin) + +### Prometheus format + +A simple text-based format for exposing metrics and ingesting them into Prometheus. + +## Q + +### query + +A request for information. +An InfluxDB query returns time series data. + +See [Query data in InfluxDB](/influxdb3/cloud-dedicated/query-data/). + +### query plan + +A sequence of steps (_nodes_) that the InfluxDB Querier devises and executes to calculate the result of the query in the least amount of time. +A _logical plan_ is a high level representation of a query and doesn't consider cluster configuration or data organization. +A _physical plan_ represents the query execution plan and data flow through plan nodes that read (_scan_), deduplicate, merge, filter, and sort data. +A physical plan is optimized for the cluster configuration and data organization. + +See [Query plans](/influxdb3/cloud-dedicated/reference/internals/query-plans/). + +## R + +### REPL + +A Read-Eval-Print Loop (REPL) is an interactive programming environment where +you type a command and immediately see the result. + +### regular expressions + +Regular expressions (regex or regexp) are patterns used to match character +combinations in strings. + +### rejected points + +In a batch of data, points that InfluxDB couldn't write to a database. +Field type conflicts are a common cause of rejected points. + +### retention period + +The [duration](#duration) of time that a database retains data. +InfluxDB drops points with timestamps older than their database's retention period +relative to [now](#now). +The minimum retention period is **one hour**. + +Related entries: +[bucket](#bucket) + +### retention policy (RP) + +A retention policy is part of the InfluxDB 1.x data model that describes how long +InfluxDB keeps data (duration), how many copies of the data to store when in a +in the cluster (replication factor), and the time range covered by shard groups +(shard group duration). RPs are unique per database and along with the measurement +and tag set define a series. + +In {{< product-name >}}, the equivalent is [retention period](#retention-period), +however retention periods are not part of the data model. +The retention period describes the data persistence behavior of a database. + +Related entries: +[retention period](#retention-period), + +### RFC3339 timestamp + +A timestamp that uses the human-readable DateTime format proposed in +[RFC 3339](https://tools.ietf.org/html/rfc3339) (for example: `2020-01-01T00:00:00.00Z`). + +Related entries: +[RFC3339Nano timestamp](#rfc3339nano-timestamp), +[timestamp](#timestamp), +[unix timestamp](#unix-timestamp) + +### RFC3339Nano timestamp + +A [Golang representation of the RFC 3339 DateTime format](https://go.dev/src/time/format.go) +that uses nanosecond resolution--for example: +`2006-01-02T15:04:05.999999999Z07:00`. + +InfluxDB clients can return RFC3339Nano timestamps in log events and CSV-formatted +query results. + +Related entries: +[RFC3339 timestamp](#rfc3339-timestamp), +[timestamp](#timestamp), +[unix timestamp](#unix-timestamp) + +### row + +A row in a [table](#table) represents a specific record or instance of data. +[Column](#column) values in a row represent specific attributes or properties of the instance. +Each row has a [primary key](/#primary-key) that makes the row unique from other rows in the table. + +Related entries: +[column](#column), +[primary key](#primary-key), +[series](#series), +[table](#table) + +## S + +### schema + +How data is organized in InfluxDB. +The fundamentals of the InfluxDB schema are databases, measurements, +tag keys, tag values, and field keys. + +Related entries: +[bucket](#bucket), +[field key](#field-key), +[measurement](#measurement), +[series](#series), +[tag key](#tag-key), +[tag value](#tag-value) + +### secret + +Secrets are key-value pairs that contain information you want to control access +to, such as API keys, passwords, or certificates. + +### selector + +A function that returns a single point from the range of specified points. +See [SQL selector functions](/influxdb3/cloud-dedicated/reference/sql/functions/selector/) +for a complete list of available SQL selector functions. + +Related entries: +[aggregate](#aggregate), +[function](#function), +[transformation](#transformation) + +### series + +In the InfluxDB 3 data structure, a collection of data that share a common +_measurement_ and _tag set_. + +Related entries: +[field set](#field-set), +[measurement](#measurement), +[tag set](#tag-set) + +### series cardinality + +The number of unique measurement (table), tag set, and field key combinations in an InfluxDB database. + +For example, assume that an InfluxDB database has one measurement. +The single measurement has two tag keys: `email` and `status`. +If there are three different `email` tag values, +and each email address is associated with two +different `status` tag values, then the series cardinality for the measurement is 6 +(3 × 2 = 6): + +| email | status | +| :-------------------- | :----- | +| lorr@influxdata.com | start | +| lorr@influxdata.com | finish | +| marv@influxdata.com | start | +| marv@influxdata.com | finish | +| cliff@influxdata.com | start | +| cliff@influxdata.com | finish | + +In some cases, performing this multiplication may overestimate series cardinality +because of the presence of dependent tags. +Dependent tags are scoped by another tag and do not increase series cardinality. +If we add the tag `firstname` to the preceding example, the series cardinality +would not be 18 (3 × 2 × 3 = 18). +The series cardinality would remain unchanged at 6, as `firstname` is already scoped by the `email` tag: + +| email | status | firstname | +| :------------------- | :----- | :-------- | +| lorr@influxdata.com | start | lorraine | +| lorr@influxdata.com | finish | lorraine | +| marv@influxdata.com | start | marvin | +| marv@influxdata.com | finish | marvin | +| cliff@influxdata.com | start | clifford | +| cliff@influxdata.com | finish | clifford | + +Related entries: +[field key](#field-key), +[measurement](#measurement), +[tag key](#tag-key), +[tag set](#tag-set) + +### series key + +A series key identifies a particular series by measurement, tag set, and field key. + +For example: + +```text +# measurement, tag set, field key +h2o_level, location=santa_monica, h2o_feet +``` + +Related entries: +[series](#series) + +### server + +A computer, virtual or physical, running InfluxDB. + + +### service input plugin + +Telegraf input plugins that run in a passive collection mode while the Telegraf agent is running. +Service input plugins listen on a socket for known protocol inputs, or apply +their own logic to ingested metrics before delivering metrics to the Telegraf agent. + +Related entries: +[aggregator plugin](#aggregator-plugin), +[input plugin](#input-plugin), +[output plugin](#output-plugin), +[processor plugin](#processor-plugin) + +### string + +A data type used to represent text. + +## T + +### TCP + +Transmission Control Protocol. + +### table + +A collection of related data organized in a structured way with a predefined set +of columns and data types. +Each row in the table represents a specific record or instance of the data, and +each column represents a specific attribute or property of the data. + +In InfluxDB Cloud Dedicated, a table represents a measurement. + +Related entries: +[column](#column), +[measurement](#measurement), +[primary key](#primary-key), +[row](#row) + +### tag + +The key-value pair in InfluxDB's data structure that records metadata. +Tags are an optional part of InfluxDB's data structure but they are useful for +storing commonly queried metadata. + +Related entries: +[field](#field), +[tag key](#tag-key), +[tag set](#tag-set), +[tag value](#tag-value) + +### tag key + +The key of a tag key-value pair. +Tag keys are strings and store metadata. + +Related entries: +[field key](#field-key), +[tag](#tag), +[tag set](#tag-set), +[tag value](#tag-value) + +### tag set + +The collection of tag keys and tag values on a point. + +Related entries: +[point](#point), +[primary key](#primary-key), +[series](#series), +[tag](#tag), +[tag key](#tag-key), +[tag value](#tag-value) + +### tag value + +The value of a tag key-value pair. +Tag values are strings and they store metadata. + +Related entries: +[tag](#tag), +[tag key](#tag-key), +[tag set](#tag-set) + +### Telegraf + +A plugin-driven agent that collects, processes, aggregates, and writes metrics. + +Related entries: +[Telegraf plugins](/telegraf/v1/plugins/), +[Use Telegraf to collect data](/influxdb3/cloud-dedicated/write-data/use-telegraf/), + +### time (data type) + +A data type that represents a single point in time with nanosecond precision. + +### time series data + +Sequence of data points typically consisting of successive measurements made +from the same source over a time interval. +Time series data shows how data evolves over time. +On a time series data graph, one of the axes is always time. +Time series data may be regular or irregular. +Regular time series data changes in constant intervals. +Irregular time series data changes at non-constant intervals. + +### timestamp + +The date and time associated with a point. +Time in InfluxDB is in UTC. + +To specify time when writing data, see +[Elements of line protocol](/influxdb3/cloud-dedicated/reference/syntax/line-protocol/#elements-of-line-protocol). + +Related entries: +[point](#point), +[unix timestamp](#unix-timestamp), +[RFC3339 timestamp](#rfc3339-timestamp) + +### token + +Tokens provide authorization to perform specific actions in InfluxDB. +There are different types of API tokens: + +- **Database token:** Grants read and write access to a database. +- **Management token:** A short-lived token that grants clients administrative + access to your InfluxDB Cloud Dedicated cluster. + +Related entries: +[Manage token](/influxdb3/cloud-dedicated/admin/tokens/) + +### transformation + +Data transformation refers to the process of converting or modifying input data from one format, value, or structure to another. + +InfluxQL [transformation functions](/influxdb3/cloud-dedicated/reference/influxql/functions/transformations/) modify and return values in each row of queried data, but do not return an aggregated value across those rows. + +Related entries: [aggregate](#aggregate), [function](#function), [selector](#selector) + +### TSM (Time Structured Merge tree) + +The InfluxDB v1 and v2 data storage format that allows greater compaction and +higher write and read throughput than B+ or LSM tree implementations. +The TSM storage engine has been replaced by the [InfluxDB 3 storage engine (IOx)](#iox). + +Related entries: +[IOx](#iox) + +## U + +### UDP + +User Datagram Protocol is a packet of information. +When a request is made, a UDP packet is sent to the recipient. +The sender doesn't verify the packet is received. +The sender continues to send the next packets. +This means computers can communicate more quickly. +This protocol is used when speed is desirable and error correction is not necessary. + +### unix epoch + +The date and time from which Unix system times are measured. +The Unix epoch is `1970-01-01T00:00:00Z`. + +### unix timestamp + +Counts time since **Unix Epoch (1970-01-01T00:00:00Z UTC)** in specified units ([precision](#precision)). +Specify timestamp precision when [writing data to InfluxDB](/influxdb3/cloud-dedicated/write-data/). +InfluxDB supports the following unix timestamp precisions: + +| Precision | Description | Example | +|:--------- |:----------- |:------- | +| `ns` | Nanoseconds | `1577836800000000000` | +| `us` | Microseconds | `1577836800000000` | +| `ms` | Milliseconds | `1577836800000` | +| `s` | Seconds | `1577836800` | + +

The examples above represent 2020-01-01T00:00:00Z UTC.

+ +Related entries: +[timestamp](#timestamp), +[RFC3339 timestamp](#rfc3339-timestamp) + +### unsigned integer + +A whole number that is positive or zero (`0`, `143`). Also known as a "uinteger." +InfluxDB supports 64-bit unsigned integers (minimum: `0`, maximum: `18446744073709551615`). + +Related entries: +[integer](#integer) + +### user + +InfluxDB users are granted permission to access to InfluxDB. + +## V + +### values per second + +The preferred measurement of the rate at which data is persisted to InfluxDB. +Write speeds are generally quoted in values per second. + +To calculate the values per second rate, multiply the number of points written +per second by the number of values stored per point. +For example, if the points have four fields each, and a batch of 5000 points is +written 10 times per second, the values per second rate is: + +**4 field values per point** × **5000 points per batch** × **10 batches per second** = **200,000 values per second** + +Related entries: +[batch](#batch), +[field](#field), +[point](#point) + +### variable + +A storage location (identified by a memory address) paired with an associated +symbolic name (an identifier). +A variable contains some known or unknown quantity of information referred to as a value. + +### variable assignment + +A statement that sets or updates the value stored in a variable. + +## W + +### WAL (Write-Ahead Log) + +The temporary cache for recently written points. +To reduce the frequency that permanent storage files are accessed, InfluxDB +caches new points in the WAL until their total size or age triggers a flush to +more permanent storage. This allows for efficient batching of the writes into +the storage engine. + +Points in the WAL are queryable and persist through a system reboot. +On process start, all points in the WAL must be flushed before the system +accepts new writes. + +### windowing + +Grouping data based on specified time intervals. +This is also referred to as "time binning" or "date binning."