A Large Number of Schemas Whose Owner Is rdsadmin

Scenario

There are a large number of schemas whose owner is rdsadmin in an RDS for PostgreSQL instance.

Possible Causes

Temporary tables in an RDS for PostgreSQL instance are classified into session-level temporary tables and transaction-level temporary tables.

• In a session-level temporary table, data exists throughout the lifecycle of a session. The default temporary table is on a per-session basis.
• In a transaction-level temporary table, data exists only in the lifecycle of a transaction.

RDS for PostgreSQL temporary tables are special tables generated in a schema named pg_temp_n, where n indicates a number that varies by session.

In this scenario, a large number of temporary tables are used by user services. These temporary tables cannot be deleted. If they are deleted, they will be re-created soon.