An Oracle database is a container database (CDB) holding pluggable databases (PDBs). Each container has several identifiers: a name such as FREEPDB1, a container ID (CON_ID) such as 3, a DBID, a unique ID (UID), and a GUID. Data dictionary views and monitoring tools report different ones, so eight CON_ functions convert between them.
Code for This Guide
The main example is in the examples/environment-functions folder of the Oracle Database 26ai code repository on GitHub, with its output. The repository also has the NIMBUS sample schema in the setup/nimbus folder.
It comes from Oracle Database 26ai SQL and PL/SQL Book.
Syntax
Syntax:
con_name_to_id(name) con_id_to_con_name(con_id) con_id_to_dbid(con_id) con_dbid_to_id(dbid) con_id_to_uid(con_id) con_uid_to_id(uid) con_id_to_guid(con_id) con_guid_to_id(guid)
| Identifier | Meaning |
|---|---|
| Name | The container's name, such as CDB$ROOT or FREEPDB1 |
| CON_ID | The number of the container within this CDB: 1 for the root, 2 for the seed, 3 and up for PDBs |
| DBID | The database identifier of the container |
| UID | A unique identifier of the PDB |
| GUID | A globally unique identifier, kept when a PDB is unplugged and plugged in elsewhere |
Convert Between Identifiers
The first query starts from the name and the CON_ID of FREEPDB1 and converts in both directions; the second goes through the GUID and UID and back.
Example:
select con_name_to_id('FREEPDB1') as con_id,
con_id_to_con_name(3) as con_name,
con_id_to_dbid(3) as dbid,
con_dbid_to_id(con_id_to_dbid(3)) as back_to_id,
con_id_to_uid(3) as uid_value
from dual;
select con_id_to_guid(3) as guid, con_guid_to_id(con_id_to_guid(3)) as from_guid,
con_uid_to_id(con_id_to_uid(3)) as from_uid
from dual;Output:
CON_ID CON_NAME DBID BACK_TO_ID UID_VALUE
_________ ___________ _____________ _____________ _____________
3 FREEPDB1 3461734982 3 3461734982
GUID FROM_GUID FROM_UID
___________________________________ ____________ ___________
5621983B6DFB0909E0630B00580A528D 3 3FREEPDB1 is container 3. Each round trip returns to 3, confirming that the conversions are inverse. Your DBID, UID, and GUID values will differ.
Where They Help
- CDB_ data dictionary views, queried in the root, have a CON_ID column; CON_ID_TO_CON_NAME turns it into a readable name, as in select con_id_to_con_name(con_id) as pdb, count(*) from cdb_tables group by con_id.
- Performance views (V$) also carry CON_ID, so the same conversion labels their rows.
- Backup and monitoring tools often record a DBID or GUID; CON_DBID_TO_ID and CON_GUID_TO_ID find the container it belongs to.
Inside a PDB, sys_context('USERENV', 'CON_NAME') and sys_context('USERENV', 'CON_ID') return the current container directly.
Related Guides
Conclusion
The CON_ functions convert between the name, container ID, DBID, UID, and GUID of the containers in a CDB. Use them to label CDB_ and V$ views by PDB name and to find the container that a DBID or GUID refers to.
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