PostgreSQL schema extraction needs namespace

To extract a database schema from PostgreSQL, the fgldbsch tool now requires db namespace specification.

In version 2.50, the fgldbsch database schema extractor can only extract the schema from a PostgreSQL database if you specify the -ow option.

Note: This behavior change is related to the bug fix FGL-2647.

PostgreSQL distinguishes table owners from table schemas (i.e. table namespaces). The real table namespace is defined by the pg_class.relnamespace column: it contains the oid of a namespace defined in pg_namespace. For PostgreSQL, the fgldbsch -ow option will specify the namespace, instead of the owner of the table, because an db user can create several schemas/namespaces and use the same table name in those different namespaces. As result, filtering on user name can mix table definitions from different schemas/namespaces.

When extracting a database schema from a PostgreSQL database, you must specify the namespace of tables with the -ow option. If no -ow option is specified and the -un option is specified, fgldbsch will use the login name of the -un option as namespace. If neither -ow, nor -up options are specified, fgldbsch will use the PostgreSQL "public" namespace/schema by default.

Since database tables are usually created in the "public" namespace, you typically specify this namespace with the -ow option:

fgldbsch -db test1 -dv dbmpgs -un pgsuser -up fourjs -v -ow public