When is it necessary to run UPDATESCHEMA

When is it necessary to run UPDATESCHEMA on a database?
After migrating a database with conv1011 must the database metaschema be updated?
What is the difference between UPDATESCHEMA and UPDATEVST?
 

What is the difference between PROUTIL UPDATESCHEMA and UPDATEVST?

• UPDATESCHEMA - Loads the specified database with newest meta-schema for the current release, for example security and auditing system tables. It can be used to check if a database meta-schema is up-to-date as defined by the installation of OpenEdge where the utility is located. 
• UPDATEVST - Loads the specified database with updated or new virtual system tables (VSTs) for the current release. For further information refer to Article:

Using PROUTIL UPDATESCHEMA

• Running UPDATESCHEMA against an offline database from the current release informs you that your database is up to date:

• UPDATESCHEMA will only make changes if it finds the schema version is not up-to-date.
• As a precaution, ensure a valid database backup before making schema changes.
• If the command is run from an older version of OpenEdge it may report an error that a feature in the database is unrecognized.

Is it necessary to run UPDATESCHEMA after migrating with conv910, conv1011 utilities?

Normally the conv utility updates an older database major release version to a newer major release version's meta-schema.

If the database was converted from version 9 to 10 with a version of the conv910 utility prior to 10.2A02, the _Db-option meta-schema table is missing for example. 

The _Db-option and _DB-detail metaschema-tables were added in OpenEdge 10.1A. These are necessary to support authentication as well as other security and auditing features of OpenEdge. Problems are usually only noticed at a much later stage in the database's history when:

• Database was initially created in or migrated to any version prior to OpenEdge 10.1A and then updated or migrated to later versions
• In later OpenEdge versions, Authentication, Security, TDE or Auditing features are added which require the _File records for _Db-option and _Db-detail which did not exist in pre-10.1A databases

The _Db-option table as well as any other metaschema changes in the current OpenEdge version, can be added to databases that were converted to from a prior-10.1A database to a OpenEdge 10.1A or later version by making use of the updateschema option.