docs-v2/content/shared/v3-line-protocol.md

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{{< product-name >}} uses line protocol to write data points.
It is a text-based format that provides the table, tag set, field set, and
timestamp of a data point.
- [Elements of line protocol](#elements-of-line-protocol)
- [Data types and format](#data-types-and-format)
- [Quotes](#quotes)
- [Special characters](#special-characters)
- [Comments](#comments)
- [Naming restrictions](#naming-restrictions)
- [Duplicate points](#duplicate-points)
```js
// Syntax
<table>[,<tag_key>=<tag_value>[,<tag_key>=<tag_value>]] <field_key>=<field_value>[,<field_key>=<field_value>] [<timestamp>]
// Example
myTable,tag1=value1,tag2=value2 fieldKey="fieldValue" 1556813561098000000
```
Lines separated by the newline character `\n` represent a single point
in InfluxDB. Line protocol is whitespace-sensitive.
> [!Note]
> Line protocol does not support the newline character `\n` in tag or field values.
## Elements of line protocol
{{< influxdb/line-protocol commas=false whitespace=false version="v3" >}}
### Table
({{< req >}})
The table name.
InfluxDB accepts one table per point.
_Table names are case-sensitive and subject to [naming restrictions](#naming-restrictions)._
_**Data type:** [String](#string)_
> [!Note]
> If familiar with previous InfluxDB versions, "**table**" is synonymous with
> "**measurement**."
### Tag set
(_**Optional**_)
All tag key-value pairs for the point.
Key-value relationships are denoted with the `=` operand.
Multiple tag key-value pairs are comma-delimited.
_Tag keys and tag values are case-sensitive.
Tag keys are subject to [naming restrictions](#naming-restrictions).
Tag values cannot be empty; instead, omit the tag from the tag set._
_**Key data type:** [String](#string)_
_**Value data type:** [String](#string)_
### Field set
({{< req >}})
All field key-value pairs for the point.
Points must have at least one field.
_Field keys and string values are case-sensitive.
Field keys are subject to [naming restrictions](#naming-restrictions)._
_**Key data type:** [String](#string)_
_**Value data type:** [Float](#float) | [Integer](#integer) | [UInteger](#uinteger) | [String](#string) | [Boolean](#boolean)_
> [!Note]
> _Always double quote string field values. More on quotes [below](#quotes)._
>
> ```sh
> tableName fieldKey="field string value" 1556813561098000000
> ```
### Timestamp
(_**Optional**_)
The [Unix timestamp](/influxdb3/version/reference/glossary/#unix-timestamp) for the data point.
InfluxDB accepts one timestamp per point.
If no timestamp is provided, InfluxDB uses the system time (UTC) of its host machine.
_**Data type:** [Unix timestamp](#unix-timestamp)_
> [!Note]
> #### Important notes about timestamps
>
> - To ensure a data point includes the time a metric is observed (not received by InfluxDB),
> include the timestamp.
> - If your timestamps are not in nanoseconds, specify the precision of your timestamps
> when writing the data to {{< product-name >}}.
### Whitespace
Whitespace in line protocol determines how InfluxDB interprets the data point.
The **first unescaped space** delimits the table and the tag set from the field set.
The **second unescaped space** delimits the field set from the timestamp.
{{< influxdb/line-protocol elements=false commas=false version="v3" >}}
## Data types and format
### Float
IEEE-754 64-bit floating-point numbers.
Default numerical type.
_InfluxDB supports scientific notation in float field values._
##### Float field value examples
```js
myTable fieldKey=1.0
myTable fieldKey=1
myTable fieldKey=-1.234456e+78
```
### Integer
Signed 64-bit integers.
Trailing `i` on the number specifies an integer.
| Minimum integer | Maximum integer |
| --------------- | --------------- |
| `-9223372036854775808i` | `9223372036854775807i` |
##### Integer field value examples
```js
myTable fieldKey=1i
myTable fieldKey=12485903i
myTable fieldKey=-12485903i
```
### UInteger
Unsigned 64-bit integers.
Trailing `u` on the number specifies an unsigned integer.
| Minimum uinteger | Maximum uinteger |
| ---------------- | ---------------- |
| `0u` | `18446744073709551615u` |
##### UInteger field value examples
```js
myTable fieldKey=1u
myTable fieldKey=12485903u
```
### String
Plain text string.
Length limit 64KB.
##### String example
```sh
# String table name, field key, and field value
myTable fieldKey="this is a string"
```
### Boolean
Stores `true` or `false` values.
| Boolean value | Accepted syntax |
|:-------------:|:--------------- |
| True | `t`, `T`, `true`, `True`, `TRUE` |
| False | `f`, `F`, `false`, `False`, `FALSE` |
##### Boolean field value examples
```js
myTable fieldKey=true
myTable fieldKey=false
myTable fieldKey=t
myTable fieldKey=f
myTable fieldKey=TRUE
myTable fieldKey=FALSE
```
> [!Note]
> Do not quote boolean field values.
> Quoted field values are interpreted as strings.
### Unix timestamp
Unix timestamp in a [specified precision](/influxdb3/version/reference/glossary/#unix-timestamp).
Default precision is nanoseconds (`ns`).
| Minimum timestamp | Maximum timestamp |
| ----------------- | ----------------- |
| `-9223372036854775806` | `9223372036854775806` |
##### Unix timestamp example
```js
myTableName fieldKey="fieldValue" 1556813561098000000
```
## Quotes
Line protocol supports single and double quotes as described in the following table:
| Element | Double quotes | Single quotes |
| :---------- | :-------------------------------------: | :-------------------------------------: |
| Table | _Limited_ <sup class="required">*</sup> | _Limited_ <sup class="required">*</sup> |
| Tag key | _Limited_ <sup class="required">*</sup> | _Limited_ <sup class="required">*</sup> |
| Tag value | _Limited_ <sup class="required">*</sup> | _Limited_ <sup class="required">*</sup> |
| Field key | _Limited_ <sup class="required">*</sup> | _Limited_ <sup class="required">*</sup> |
| Field value | **Strings only** | Never |
| Timestamp | Never | Never |
<sup class="required">\*</sup> _Line protocol accepts double and single quotes in
table names, tag keys, tag values, and field keys, but interprets them as
part of the name, key, or value._
## Special Characters
Line protocol supports special characters in [string elements](#string).
In the following contexts, it requires escaping certain characters with a backslash (`\`):
| Element | Escape characters |
| :---------- | :------------------------ |
| Table | Comma, Space |
| Tag key | Comma, Equals Sign, Space |
| Tag value | Comma, Equals Sign, Space |
| Field key | Comma, Equals Sign, Space |
| Field value | Double quote, Backslash |
You do not need to escape other special characters.
##### Examples of special characters in line protocol
```sh
# Table name with spaces
my\ Table fieldKey="string value"
# Double quotes in a string field value
myTable fieldKey="\"string\" within a string"
# Tag keys and values with spaces
myTable,tag\ Key1=tag\ Value1,tag\ Key2=tag\ Value2 fieldKey=100
# Emojis
myTable,tagKey=🍭 fieldKey="Launch 🚀" 1556813561098000000
```
### Escaping backslashes
Line protocol supports both literal backslashes and backslashes as an escape character.
With two contiguous backslashes, the first is interpreted as an escape character.
For example:
| Backslashes | Interpreted as |
| :---------- | :------------- |
| `\` | `\` |
| `\\` | `\` |
| `\\\` | `\\` |
| `\\\\` | `\\` |
| `\\\\\` | `\\\` |
| `\\\\\\` | `\\\` |
## Comments
Line protocol interprets `#` at the beginning of a line as a comment character
and ignores all subsequent characters until the next newline `\n`.
```sh
# This is a comment
myTable fieldKey="string value" 1556813561098000000
```
## Naming restrictions
Table names, tag keys, and field keys are alphanumeric and must begin with a
letter or a number. They can contain dashes (`-`) and underscores (`_`).
## Duplicate points
A point is uniquely identified by the table name, tag set, and timestamp.
If you submit line protocol with the same table, tag set, and timestamp,
but with a different field set, the field set becomes the union of the old
field set and the new field set, where any conflicts favor the new field set.
{{% show-in "cloud-dedicated,clustered" %}}
> [!Important]
> #### Write ordering for duplicate points
>
> {{% product-name %}} attempts to honor write ordering for duplicate points,
> with the most recently written point taking precedence. However, when data is
> flushed from the in-memory buffer to Parquet files—typically every 15 minutes,
> but sometimes sooner—this ordering is not guaranteed if duplicate points are
> flushed at the same time. As a result, the last written duplicate point may
> not always be retained in storage.
{{% /show-in %}}