Convert a physical standby to a snapshot standby and back (test environment)

Command

# Make the standby read-write (redo is still received, apply stops):
CONVERT DATABASE '<standby_db_unique_name>' TO SNAPSHOT STANDBY;
SHOW DATABASE '<standby_db_unique_name>';
# ... testing / application validation ...
# Convert back: all test changes are discarded, accumulated redo is applied
CONVERT DATABASE '<standby_db_unique_name>' TO PHYSICAL STANDBY;
SHOW CONFIGURATION;

What it does

Creates an automatic guaranteed restore point on the standby and opens it read-write; when converting back it flashes back to that point and applies the redo accumulated from the primary.

When to use it

To rehearse an upgrade, test an application release or run Real Application Testing (DB Replay) on production data without creating a separate copy.

Caution

While it is a snapshot standby no redo is applied: the RPO is preserved but the failover time (RTO) grows with the accumulated redo, and it cannot be an FSFO target. Flashback logs can fill the FRA; monitor FRA space. Changes made in the snapshot are permanently discarded when converting back.