Migration Assessment

Review allocated datafile space to establish the source database footprint.

SELECT
  ROUND(SUM(bytes) / 1024 / 1024 / 1024, 2) AS allocated_gb,
  COUNT(*) AS datafiles
FROM dba_data_files;

Identify schemas and account status before planning users, ownership and migration scope.

SELECT
  username,
  account_status,
  default_tablespace,
  temporary_tablespace,
  created
FROM dba_users
ORDER BY username;

Count objects by schema and type to understand application and metadata complexity.

SELECT
  owner,
  object_type,
  COUNT(*) AS object_count
FROM dba_objects
GROUP BY owner, object_type
ORDER BY owner, object_type;

Identify invalid database objects that should be understood before or after the move.

SELECT
  owner,
  object_type,
  object_name,
  status
FROM dba_objects
WHERE status <> 'VALID'
ORDER BY owner, object_type, object_name;

Review enabled database options that may influence migration planning and target requirements.

SELECT
  parameter,
  value
FROM v$option
ORDER BY parameter;

Review object relationships that can help identify migration ordering and validation requirements.

SELECT
  owner,
  name,
  type,
  referenced_owner,
  referenced_name,
  referenced_type
FROM dba_dependencies
ORDER BY owner, name, referenced_owner, referenced_name;