influxdb3 create last_cache
The influxdb3 create last_cache
command creates a last value cache, which stores the most recent values for specified columns in a table. Use this to efficiently retrieve the latest values based on key column combinations.
Usage
influxdb3 create last_cache [OPTIONS] \
--database DATABASE_NAME \
--table TABLE_NAME \
--token AUTH_TOKEN \
CACHE_NAME
Arguments
- CACHE_NAME: (Optional) Name for the cache. If omitted, InfluxDB automatically generates one.
Options
Option | Description | |
---|---|---|
-H | --host | Host URL of the running InfluxDB 3 Core server (default is http://127.0.0.1:8181 ) |
-d | --database | (Required) Name of the database to operate on |
--token | (Required) Authentication token | |
-t | --table | (Required) 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 as substitutes for CLI options:
Environment Variable | Option |
---|---|
INFLUXDB3_HOST_URL | --host |
INFLUXDB3_DATABASE_NAME | --database |
INFLUXDB3_AUTH_TOKEN | --token |
Prerequisites
Before creating a last value cache, ensure you’ve done the following:
- Create a database.
- Create a table with the columns you want to cache.
- Have a valid authentication token.
Examples
A last value cache stores the most recent values from specified columns in a table.
Create a basic last value cache for one column
The following example shows how to track the most recent value for a single key (the last temperature for each room):
influxdb3 create last_cache \
--database DATABASE_NAME \
--table my_sensor_table \
--token AUTH_TOKEN \
--key-columns room \
--value-columns temp \
my_temp_cache
Create a last value cache with multiple keys and values
The following example shows how to:
- Use multiple columns as a composite key
- Track several values per key combination
- Set a cache entry limit with
--count
- Configure automatic expiry with
--ttl
influxdb3 create last_cache \
--database DATABASE_NAME \
--table my_sensor_table \
--token AUTH_TOKEN \
--key-columns room,sensor_id \
--value-columns temp,hum \
--count 10 \
--ttl 1h \
my_sensor_cache
Usage notes
- Define the table schema to include all specified key and value columns.
- Pass tokens using
--token
, unless you’ve set one through an environment variable. - Specify
--count
and--ttl
to override the defaults; otherwise, the system uses default values.
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