Create/Open/Close/Save State for PDBs and Service-Based Connection Management

Learning outcomes

A maintenance restart completes successfully, but ServiceHub cannot connect. The listener is up, the CDB is open, and the operator can log in through the FREE service—yet the application PDB is mounted. Multitenant availability has two layers: the instance/CDB must be available, and the target PDB plus its service must be open/registered for the client workload.

1. Creation starts mounted; first READ WRITE open completes integration

A new PDB created from PDB$SEED starts mounted with status NEW. Oracle requires the first open in READ WRITE mode to complete integration and transition the PDB status to NORMAL. Creation also establishes a default service with the same name as the PDB.

SHOW CON_NAME-- Must be CDB$ROOT.SELECT value AS db_create_file_destFROM v$parameterWHERE name='db_create_file_dest';SELECT COUNT(*) AS current_pdbsFROM dba_pdbs;SELECT name,open_mode,total_sizeFROM v$pdbsORDER BY con_id;

The optional creation path below assumes Oracle Managed Files (OMF): DB_CREATE_FILE_DEST is non-null, enough Free user-data/storage capacity remains, and you are connected with CREATE PLUGGABLE DATABASE/SYSDBA authority. If OMF is not configured, do not guess file paths; continue the mandatory state/service lab with FREEPDB1.

2. Optional Free local PDB creation

ACCEPT sh13_pwd CHAR PROMPT 'Password for SH13ADMIN: ' HIDECREATE PLUGGABLE DATABASE sh13lab  ADMIN USER sh13admin  IDENTIFIED BY "&sh13_pwd";ALTER PLUGGABLE DATABASE sh13lab OPEN READ WRITE;SELECT pdb_name,statusFROM dba_pdbsWHERE pdb_name='SH13LAB';SELECT name,open_mode,restrictedFROM v$pdbsWHERE name='SH13LAB';

Do not run the creation command if OMF is absent or Free capacity is tight. A non-OMF deployment needs an intentionally designed FILE_NAME_CONVERT/PDB_FILE_NAME_CONVERT strategy tied to actual storage.

3. Open/close state is independent of the CDB being open

ALTER PLUGGABLE DATABASE FREEPDB1 CLOSE IMMEDIATE;SELECT name,open_modeFROM v$pdbsWHERE name='FREEPDB1';-- MOUNTEDALTER PLUGGABLE DATABASE FREEPDB1 OPEN READ WRITE;SELECT name,open_modeFROM v$pdbsWHERE name='FREEPDB1';-- READ WRITE

CLOSE IMMEDIATE terminates/disconnects affected PDB workload; schedule it like downtime. Do not run it while the ServiceHub application is active unless this is a disposable lab instance.

4. SAVE STATE makes restart intent explicit

Without saved state, PDB behavior after instance/CDB startup can differ from application expectations. SAVE STATE records the current open mode for future instance restarts. DBA_PDB_SAVED_STATES is the evidence that the state was preserved; it is not proof that a future startup actually succeeded.

ALTER PLUGGABLE DATABASE FREEPDB1 OPEN READ WRITE;ALTER PLUGGABLE DATABASE FREEPDB1 SAVE STATE;SELECT  con_name,  instance_name,  state,  restrictedFROM dba_pdb_saved_statesWHERE con_name='FREEPDB1';

ALTER PLUGGABLE DATABASE FREEPDB1 DISCARD STATE;

After testing DISCARD STATE, restore the course baseline with SAVE STATE if automatic PDB opening is expected.

5. Service names route sessions to PDBs; a SID identifies an instance

In multitenant client configuration, use a service associated with the PDB. The Oracle AI Database Free defaults are FREE for root and FREEPDB1 for the default PDB. Each new PDB gets a default service with the same name. An Oracle System Identifier (SID) identifies an instance; it is not a PDB routing key.

SELECT  name,  network_name,  pdb,  enabledFROM v$servicesORDER BY name;

lsnrctl status

lsnrctl status proves what services the listener currently advertises. It does not prove that application credentials are valid or that a session lands in the desired container after connecting.

6. Deliberately wrong: connect successfully to FREE and assume it is ServiceHub

sql system@//localhost:1521/FREESELECT SYS_CONTEXT('USERENV','CON_NAME') AS con_nameFROM dual;-- CDB$ROOT

A root connection can be operationally powerful, so this is not merely a query-result error. The repair is to use the PDB service and verify container identity.

sql sh13admin@//localhost:1521/SH13LAB-- or the course PDB:-- sql servicehub_owner@//localhost:1521/FREEPDB1SELECT  SYS_CONTEXT('USERENV','CON_NAME') AS con_name,  SYS_CONTEXT('USERENV','SERVICE_NAME') AS service_nameFROM dual;

7. Service design in production

The PDB default service is convenient for administration and labs, but production applications should use purpose-built services when workload routing, drain behavior, failover, connection-pool configuration, or workload management needs distinct identities. Service management differs between single-instance and Oracle RAC/Grid Infrastructure deployments; do not copy srvctl procedures into a standalone Free installation.

8. Optional cleanup for SH13LAB

ALTER SESSION SET CONTAINER=CDB$ROOT;ALTER PLUGGABLE DATABASE sh13lab CLOSE IMMEDIATE;DROP PLUGGABLE DATABASE sh13lab INCLUDING DATAFILES;

Never use INCLUDING DATAFILES on a PDB whose files or backups you still need. Verify the PDB name and container before the drop.

9. Production judgment

Treat CDB availability, PDB open state, service registration, listener reachability, credential success, and session container identity as separate checkpoints. Save PDB state intentionally and monitor it after maintenance. Use service names for PDB clients, not instance SID assumptions.

No pack or COMPATIBLE change is required. Optional PDB creation consumes Free's finite user-data/storage budget. Lesson 3 now moves a PDB through cloning and portability workflows where file ownership, local undo, compatibility, service collisions, and topology become decisive.

Authoritative references

• Creating a PDB from Scratch — seed creation, NEW/NORMAL status and default service
• ALTER PLUGGABLE DATABASE — open/close/save/discard-state syntax and privileges
• DBA_PDB_SAVED_STATES — saved-state evidence
• V$SERVICES — service-to-PDB mapping
• Connecting to Oracle AI Database Free — FREE/FREEPDB1 services and Easy Connect