Retention Policy

• How long InfluxDB should keep data
• What number of copies to store in a cluster (not meaningful in one-node cluster)
• Time range for shard groups
• Default Retention Policy autogen is created when database is created
• autogen comes with infinite duration, a replication factor of one, and a shard group duration of seven days
• Custom retention policy can be specified when creating a database:

  create database "fliesbees" with duration 1m replication 1 shard duration 1s name "ephemeral"
  

• A new retention policy can be created in an existing database and set as a default:

  create retention policy "ephemeral" on "fliesbees" duration 1h replication 1 default
  

• Retention policy duration:

  m minutes
  h hours
  d days
  w weeks
  INF infinite
  

• Writing data using non-default retention policy:

  INSERT INTO [<database>.]<retention_policy> <line_protocol>
  

• Reading data using non-default retention policy:

  select * from [<database>.]<retention_policy>.<measurement>
  

• Purge is not instant: InfluxDB checks to enforce an RP every 30 minutes