The Enterprise Manager is supposed to purge the appmap_states_ddmmyyyy tables automatically and the frequency of this purging is controlled by the property introscope.apm.data.preserving.time. However due to a problem in 10.0 and 10.1 this does not occur and you may see the message in the console output from the Enterprise Manager
INFO | jvm 1 | 2016/04/19 12:14:14 | org.springframework.jdbc.UncategorizedSQLException: StatementCallback; uncategorized SQLException for SQL [DROP TABLE appmap_states_20160217]; SQL state ; error code ; ERROR: cannot execute DROP TABLE in a read-only transaction; nested exception is org.postgresql.util.PSQLException: ERROR: cannot execute DROP TABLE in a read-only transaction
This problem could result in excessive space being using in the APM database.
APM 10.0 and 10.1 (Postgres or Oracle)
Manually drop the tables e.g.
DROP TABLE appmap_states_20160217
This problem is addressed in 10.2.0.23 and later releases