docs-v2/content/shared/influxdb3-cli/create/last_cache.md

The influxdb3 create last_cache command creates a new last value cache.

Usage

influxdb3 create last_cache [OPTIONS] \
  --database <DATABASE_NAME> \
  --table <TABLE_NAME> \
  [CACHE_NAME]

Arguments

• CACHE_NAME: (Optional) Name for the cache. If not provided, the command automatically generates a name.

Options

Option		Description
-H	--host	Host URL of the running {{< product-name >}} server (default is http://127.0.0.1:8181)
-d	--database	({{< req >}}) Name of the database to operate on
	--token	({{< req >}}) Authentication token
-t	--table	({{< req >}}) Table to create the cache for
	--key-columns	Comma-separated list of columns to use as keys in the cache--for example: foo,bar,baz
	--value-columns	Comma-separated list of columns to store as values in the cache--for example: foo,bar,baz
	--count	Number of entries per unique key column combination to store in the cache
	--ttl	Cache entries' time-to-live (TTL) in Humantime form--for example: 10s, 1min 30sec, 3 hours
	--tls-ca	Path to a custom TLS certificate authority (for testing or self-signed certificates)
-h	--help	Print help information
	--help-all	Print detailed help information

Option environment variables

You can use the following environment variables to set command options:

Environment Variable	Option
INFLUXDB3_HOST_URL	--host
INFLUXDB3_DATABASE_NAME	--database
INFLUXDB3_AUTH_TOKEN	--token

Prerequisites

Before creating a last value cache, you must:

Before creating a distinct value cache, you must:

1. Create a database.

2. Create a table with the columns you want to cache.

3. Have a valid authentication token.

Examples

Generic syntax

{{% code-placeholders "(DATABASE|TABLE|CACHE)_NAME (TAG_COLUMN|FIELD_COLUMN)" %}}

influxdb3 create last_cache \
  --database DATABASE_NAME \
  --table TABLE_NAME \
  --key-columns TAG_COLUMN \
  --value-columns FIELD_COLUMN \
  CACHE_NAME

In the example above, replace the following:

• {{% code-placeholder-key %}}DATABASE_NAME{{% /code-placeholder-key %}}: Database name
• {{% code-placeholder-key %}}TABLE_NAME{{% /code-placeholder-key %}}: Table name
• {{% code-placeholder-key %}}TAG_COLUMN{{% /code-placeholder-key %}}: Column to use as the key in the cache
• {{% code-placeholder-key %}}FIELD_COLUMN{{% /code-placeholder-key %}}: Column to store as the value in the cache
• {{% code-placeholder-key %}}CACHE_NAME{{% /code-placeholder-key %}}: Optional name for the last value cache

Create a basic last value cache for one column

Use this example to create a simple cache for a single key and value column:

influxdb3 create last_cache \
  --database my_test_db \
  --table my_sensor_table \
  --key-columns room \
  --value-columns temp \
  my_temp_cache

Create a last value cache with multiple keys and values

This example shows how to configure a more complex cache:

influxdb3 create last_cache \
  --database my_test_db \
  --table my_sensor_table \
  --key-columns room,sensor_id \
  --value-columns temp,hum \
  --count 10 \
  --ttl 1h \
  my_sensor_cache

{{% /code-placeholders %}}

Common pitfalls

• All specified key and value columns must exist in the table schema.
• Tokens must be passed with --token unless set via environment variable.
• If not specified, default values are used for --count and --ttl.