Introduction

Oracle 26ai is not yet available on Bare Metal ODA, but it will probably be in a few weeks. For now, 26ai is available as a DB System on Oracle Database Appliance, meaning that it’s already possible to test this new version. Let’s try to migrate a 19c Bare Metal PDB to a 26ai DB System using 3 different methods.

Prerequisites

26ai is only available with the minimum release 19.29, meaning on ODA X8-2 and newer models. You will need to patch your ODA to 19.29 first if you want to test 26ai. 26ai is only compatible with multitenant architecture, so another prerequisite is to migrate your non-container databases to PDBs. If you’re still using non-CDB architecture, and among these 3 methods, only the first one will work for you.

The recommended patching method as told by Oracle is using AutoUpgrade: please refer to this blog post if you want more details.

On my side, I will explore these 3 other possibilities:

  • Datapump Export/Import
  • PDB copy through a DB link
  • PDB unplug/plug

Download the needed files for 26ai DB System

These files are needed for creating a 26ai DB System:

36524660 => System image for 26ai DB Systems
36524627 => the GI clone needed for deploying newer 26ai GI version
36524642 => the DB clone for deploying new version 26ai

Be sure to choose the very latest 19.29 patch when downloading these files, download link from MOS will first propose older versions.

My 19c source database

My source database is a 19c container database with one PDB running on an ODA X8-2M. I want to migrate this PDB to 26ai:

su - oracle
 . oraenv <<< CPROD19
ORACLE_SID = [CPROD19] ? The Oracle base remains unchanged with value /u01/app/odaorabase/oracle
sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Thu Jan 8 09:53:43 2026
Version 19.29.0.0.0

Copyright (c) 1982, 2025, Oracle.  All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.29.0.0.0

show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 PRODDB01                       READ WRITE NO

exit

Provision a new 26ai DB System

It’s not yet possible to deploy a 26ai container database on Bare Metal, so let’s create a DB System for testing this migration. First unzip and register the VM template, GI 26ai and DB 26ai:

cd /opt/dbi

unzip -o p36524660_1929000_Linux-x86-64.zip
unzip -o p36524627_1929000_Linux-x86-64.zip
unzip -o p36524642_1929000_Linux-x86-64.zip

odacli update-repository -f /opt/dbi/odacli-dcs-23.26.0.0.0-251116-ODAVM-19.29.0.0.zip
odacli update-repository -f /opt/dbi/odacli-dcs-23.26.0.0.0-251116-GI-23.26.0.0.zip
odacli update-repository -f /opt/dbi/odacli-dcs-23.26.0.0.0-251116-DB-23.26.0.0.zip

sleep 30 ; odacli list-jobs | tail -n 4
d4700315-db8c-4522-af55-0fddd262bfe4     Repository Update                                                           2025-12-08 15:20:14 CET             Success
ba7d452f-e03d-46d0-a607-fd7c758cd1b1     Repository Update                                                           2025-12-08 15:20:59 CET             Success
bfc102d1-985b-4792-8054-03709aa8d949     Repository Update                                                           2025-12-08 15:21:20 CET             Success

odacli describe-dbsystem-image | grep 23.26
DBVM                  23.26.0.0.0           23.26.0.0.0
GI                    23.26.0.0.0           23.26.0.0.0
DB                    23.26.0.0.0           23.26.0.0.0

A CPU pool is needed for DB Systems, if you don’t have one. A 2-core CPU pool is enough:

odacli create-cpupool -c 2 -n cpupool2c -dbs

Now let’s create a json file, then create a new DB System based on this file:

cat /opt/dbi/create_dbs-04-tst-cdb.json
{
    "system": {
        "name": "dbs-04-tst",
        "shape": "dbs2",
        "systemPassword": "***********",
        "timeZone": "Europe/Zurich",
        "diskGroup": "DATA",
        "cpuPoolName": "cpupool2c",
        "enableRoleSeparation": true,
        "customRoleSeparation": {
            "groups": [
                {
                    "name": "oinstall",
                    "id": 1001,
                    "role": "oinstall"
                },
                {
                    "name": "dbaoper",
                    "id": 1002,
                    "role": "dbaoper"
                },
                {
                    "name": "dba",
                    "id": 1003,
                    "role": "dba"
                },
                {
                    "name": "asmadmin",
                    "id": 1004,
                    "role": "asmadmin"
                },
                {
                    "name": "asmoper",
                    "id": 1005,
                    "role": "asmoper"
                },
                {
                    "name": "asmdba",
                    "id": 1006,
                    "role": "asmdba"
                }
            ],
            "users": [
                {
                    "name": "grid",
                    "id": 1001,
                    "role": "gridUser"
                },
                {
                    "name": "oracle",
                    "id": 1000,
                    "role": "oracleUser"
                }
            ]
        }
    },
    "database": {
        "name": "CTEST26",
        "uniqueName": "CTEST26_S1",
        "domainName": "dbi-lab.ch",
        "adminPassword": "**********",
        "version": "23.26.0.0.0",
        "edition": "EE",
        "type": "SI",
        "dbClass": "OLTP",
        "shape": "odb2",
        "role": "PRIMARY",
        "enableDbConsole": false,
        "enableFlashStorage": false,
        "redundancy": null,
        "characterSet": {
            "characterSet": "AL32UTF8",
            "nlsCharacterset": "AL16UTF16",
            "dbTerritory": "AMERICA",
            "dbLanguage": "AMERICAN"
        },
        "rmanBackupPassword": null,
        "enableTDE": false,
        "isCdb": true,
        "pdbName": "pdb1",
        "pdbAdminUser": "pdbadmin",
        "tdePassword": null
    },
    "network": {
        "domainName": "dbi-lab.ch",
        "ntpServers": [
            "85.195.224.28"
        ],
        "dnsServers": [
            "10.16.0.250"
        ],
        "nodes": [
            {
                "name": "dbs-04-tst",
                "ipAddress": "10.16.0.247",
                "netmask": "255.255.255.0",
                "gateway": "10.16.0.1",
                "number": 0
            }
        ],
        "publicVNetwork": "pubnet"
    },
    "grid": {
        "language": "en"
    }
}

odacli create-dbsystem -p /opt/dbi/create_dbs-04-tst-cdb.json
Enter password for system "dbs-04-tst":
Retype password for system "dbs-04-tst":
Enter administrator password for DB "CTEST26":
Retype administrator password for DB "CTEST26":
...

35 minutes later, my new DB System is ready to use:

odacli describe-job -i c79ecbbf-dd0c-4b75-ba10-249c78b25f33

Job details
----------------------------------------------------------------
                     ID:  c79ecbbf-dd0c-4b75-ba10-249c78b25f33
            Description:  DB System dbs-04-tst creation
                 Status:  Success
                Created:  January 08, 2026 10:23:39 CET
                Message:

Task Name                                Start Time                               End Time                                 Status
---------------------------------------- ---------------------------------------- ---------------------------------------- ----------------
Create DB System metadata                January 08, 2026 10:23:39 CET            January 08, 2026 10:23:41 CET            Success
Persist new DB System                    January 08, 2026 10:23:41 CET            January 08, 2026 10:23:41 CET            Success
Remove unused network interfaces         January 08, 2026 10:23:41 CET            January 08, 2026 10:23:41 CET            Success
Validate DB System creation              January 08, 2026 10:23:41 CET            January 08, 2026 10:23:46 CET            Success
Create the infra quota group             January 08, 2026 10:23:46 CET            January 08, 2026 10:23:50 CET            Success
Setup DB System environment              January 08, 2026 10:23:46 CET            January 08, 2026 10:23:46 CET            Success
Create DB System ASM volume              January 08, 2026 10:23:50 CET            January 08, 2026 10:24:01 CET            Success
Create DB System ACFS filesystem         January 08, 2026 10:24:01 CET            January 08, 2026 10:24:13 CET            Success
Create DB System ACFS mount point        January 08, 2026 10:24:01 CET            January 08, 2026 10:24:01 CET            Success
Create DB System VM ACFS snapshots	 January 08, 2026 10:24:13 CET            January 08, 2026 10:24:28 CET            Success
Setup ASM client cluster config          January 08, 2026 10:24:28 CET            January 08, 2026 10:24:30 CET            Success
Create temporary SSH key pair            January 08, 2026 10:24:30 CET            January 08, 2026 10:24:31 CET            Success
Create BM certificates in ACFS location  January 08, 2026 10:24:31 CET            January 08, 2026 10:24:32 CET            Success
Create DB System cloud-init config	 January 08, 2026 10:24:32 CET            January 08, 2026 10:24:32 CET            Success
Provision DB System VM(s)                January 08, 2026 10:24:32 CET            January 08, 2026 10:24:35 CET            Success
Create u01 vDisk for DB System           January 08, 2026 10:24:35 CET            January 08, 2026 10:24:36 CET            Success
Add DB System to Clusterware             January 08, 2026 10:24:36 CET            January 08, 2026 10:24:37 CET            Success
Attach disks to DB System                January 08, 2026 10:24:36 CET            January 08, 2026 10:24:36 CET            Success
Attach u01 vDisk to DB System            January 08, 2026 10:24:36 CET            January 08, 2026 10:24:36 CET            Success
Add extra PCI slots                      January 08, 2026 10:24:37 CET            January 08, 2026 10:24:37 CET            Success
Create Network Filters                   January 08, 2026 10:24:37 CET            January 08, 2026 10:24:37 CET            Success
Export clones repository                 January 08, 2026 10:24:37 CET            January 08, 2026 10:24:37 CET            Success
Start DB System                          January 08, 2026 10:24:37 CET            January 08, 2026 10:24:40 CET            Success
Wait DB System VM first boot             January 08, 2026 10:24:40 CET            January 08, 2026 10:26:49 CET            Success
Setup Mutual TLS (mTLS)                  January 08, 2026 10:26:49 CET            January 08, 2026 10:26:51 CET            Success
Cleanup temporary SSH key pair           January 08, 2026 10:26:51 CET            January 08, 2026 10:26:52 CET            Success
Copy ASM client cluster config           January 08, 2026 10:26:51 CET            January 08, 2026 10:26:51 CET            Success
Delete Mutual TLS (mTLS) Artifacts	 January 08, 2026 10:26:51 CET            January 08, 2026 10:26:51 CET            Success
Wait DB System VM DCS Agent readiness    January 08, 2026 10:26:52 CET            January 08, 2026 10:27:12 CET            Success
Add Network Filters                      January 08, 2026 10:27:12 CET            January 08, 2026 10:27:14 CET            Success
Install DB System                        January 08, 2026 10:27:14 CET            January 08, 2026 10:53:57 CET            Success
Wait DB System VM DCS Agent readiness    January 08, 2026 10:53:57 CET            January 08, 2026 10:55:58 CET            Success
Set DB System as configured              January 08, 2026 10:55:58 CET            January 08, 2026 10:55:58 CET            Success

odacli list-dbsystems

Name                  Shape       GI version          DB info                         Status                  Created                   Updated
--------------------  ----------  ------------------  ------------------------------  ----------------------  ------------------------  ------------------------
dbs-04-tst            dbs2        23.26.0.0.0         23.26(CONFIGURED=1)             CONFIGURED              2026-01-08 10:23:39 CET   2026-01-08 10:55:58 CET

Migration using datapump

Let’s consider a classic migration using datapump. This tool has been the official one for migration for nearly 2 decades now.

Let’s first create a new PDB inside the container database of the new DB System:

ssh root@dbs-04-tst
su - oracle
. oraenv <<< CTEST26
sqlplus / as sysdba
show pdbs
    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 3 PDB1 			  READ WRITE NO

alter pluggable database PDB1 close immediate;
Pluggable database altered.

drop pluggable database PDB1 including datafiles;
Pluggable database dropped.

create pluggable database MIG26DTPUMP admin user pdbadmin identified by "*********";
Pluggable database created.

alter pluggable database MIG26DTPUMP open;
Pluggable database altered.

alter pluggable database MIG26DTPUMP save state;
Pluggable database altered.

show pdbs
    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 4 MIG26DTPUMP			  READ WRITE NO

alter session set container=MIG26DTPUMP;

create tablespace users datafile size 100M autoextend on maxsize 10G;
Tablespace created.

exit

On source database, non-CDB or PDB it doesn’t matter, export data using datapump:

su - oracle
. oraenv <<< CPROD19
export ORACLE_PDB_SID=PRODDB01
sqlplus / as sysdba
create or replace directory mig as '/backup/dumps/';
col current_scn for 999999999999
select current_scn from v$database;
    CURRENT_SCN
---------------
        6292616
exit
expdp system directory=MIG full=y dumpfile=PRODDB01_20260112.dmp logfile=exp_PRODDB01_20260112.log flashback_scn=6292616

Export: Release 19.0.0.0.0 - Production on Mon Jan 12 10:36:52 2026
Version 19.29.0.0.0

Copyright (c) 1982, 2019, Oracle and/or its affiliates.  All rights reserved.
Password:

Connected to: Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Starting "SYSTEM"."SYS_EXPORT_FULL_01":  system/******** directory=MIG full=y dumpfile=PRODDB01_20260112.dmp logfile=exp_PRODDB01_20260112.log flashback_scn=6292616
Processing object type DATABASE_EXPORT/EARLY_OPTIONS/VIEWS_AS_TABLES/TABLE_DATA
Processing object type DATABASE_EXPORT/NORMAL_OPTIONS/TABLE_DATA
Processing object type DATABASE_EXPORT/NORMAL_OPTIONS/VIEWS_AS_TABLES/TABLE_DATA
Processing object type DATABASE_EXPORT/SCHEMA/TABLE/TABLE_DATA
Processing object type DATABASE_EXPORT/SCHEMA/TABLE/INDEX/STATISTICS/INDEX_STATISTICS
Processing object type DATABASE_EXPORT/SCHEMA/TABLE/STATISTICS/TABLE_STATISTICS
Processing object type DATABASE_EXPORT/STATISTICS/MARKER
Processing object type DATABASE_EXPORT/PRE_SYSTEM_IMPCALLOUT/MARKER
Processing object type DATABASE_EXPORT/PRE_INSTANCE_IMPCALLOUT/MARKER
Processing object type DATABASE_EXPORT/TABLESPACE
...

. . exported "WMSYS"."WM$METADATA_MAP"                   11.16 KB       0 rows
. . exported "MDSYS"."RDF_PARAM$"                        6.515 KB       3 rows
. . exported "SYS"."AUDTAB$TBS$FOR_EXPORT"               5.960 KB       2 rows
. . exported "SYS"."DBA_SENSITIVE_DATA"                  8.070 KB       0 rows
. . exported "SYS"."DBA_TSDP_POLICY_PROTECTION"          7.656 KB       0 rows
. . exported "SYS"."NACL$_ACE_EXP"                       9.812 KB       0 rows
. . exported "SYS"."NACL$_HOST_EXP"                      6.921 KB       1 rows
. . exported "SYS"."NACL$_WALLET_EXP"                    5.929 KB       0 rows
. . exported "DBI"."CONSULTANTS"                         5.937 KB       1 rows
Master table "SYSTEM"."SYS_EXPORT_FULL_01" successfully loaded/unloaded
******************************************************************************
Dump file set for SYSTEM.SYS_EXPORT_FULL_01 is:
  /backup/dumps/PRODDB01_20260112.dmp
Job "SYSTEM"."SYS_EXPORT_FULL_01" successfully completed at Mon Jan 12 10:38:52 2026 elapsed 0 00:01:54


ls -lrth /backup/dumps/*20260112*
-rw-r-----. 1 oracle asmadmin  34M Jan 12 10:38 /backup/dumps/PRODDB01_20260112.dmp
-rw-r--r--. 1 oracle asmadmin 9.8K Jan 12 10:38 /backup/dumps/exp_PRODDB01_20260112.log

On target database, let’s do the import:

ssh root@dbs-04-tst
su - oracle
. oraenv <<< CTEST26
export ORACLE_PDB_SID=MIG26DTPUMP
sqlplus / as sysdba
create or replace directory mig as '/backup/dumps/';
exit

vi /backup/dumps/imp_PRODDB01.par
directory=MIG
schemas=dbi
dumpfile=PRODDB01_20260112.dmp
logfile=imp_PRODDB01_to_MIG26DTPUMP_20260112.log
exclude=statistics

impdp system parfile=/backup/dumps/imp_PRODDB01.par
Import: Release 23.26.0.0.0 - for Oracle Cloud and Engineered Systems on Mon Jan 12 10:51:39 2026
Version 23.26.0.0.0

Copyright (c) 1982, 2025, Oracle and/or its affiliates.  All rights reserved.
Password:

Connected to: Oracle AI Database 26ai Enterprise Edition Release 23.26.0.0.0 - for Oracle Cloud and Engineered Systems
Master table "SYSTEM"."SYS_IMPORT_SCHEMA_01" successfully loaded/unloaded
import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
export done in WE8MSWIN1252 character set and AL16UTF16 NCHAR character set
Warning: possible data loss in character set conversions
Starting "SYSTEM"."SYS_IMPORT_SCHEMA_01":  system/******** parfile=/backup/dumps/imp_PRODDB01.par
Processing object type DATABASE_EXPORT/SCHEMA/USER
Processing object type DATABASE_EXPORT/SCHEMA/GRANT/SYSTEM_GRANT
Processing object type DATABASE_EXPORT/SCHEMA/ROLE_GRANT
Processing object type DATABASE_EXPORT/SCHEMA/DEFAULT_ROLE
Processing object type DATABASE_EXPORT/SCHEMA/PROCACT_SCHEMA/LOGREP
Processing object type DATABASE_EXPORT/SCHEMA/TABLE/TABLE
Processing object type DATABASE_EXPORT/SCHEMA/TABLE/TABLE_DATA
. . imported "DBI"."CONSULTANTS"                           5.9 KB       1 rows
Job "SYSTEM"."SYS_IMPORT_SCHEMA_01" successfully completed at Mon Jan 12 10:51:54 2026 elapsed 0 00:00:08

Let’s now compute statistics for my schema:

sqlplus / as sysdba
exec dbms_stats.gather_schema_stats(ownname => 'DBI');
PL/SQL procedure successfully completed.
exit;

Let’s do a quick check on data:

sqlplus / as sysdba
select start_date from dbi.consultants where name like 'DUB%';

START_DAT
---------
04-SEP-17

exit

That’s fine.

Pros & cons

  • + Same procedure as previous migrations
  • + Reorganize data and indexes
  • + Keep the source database untouched
  • – Rather slow when database is big

If the source database is a PDB, it can be copied through a DB link, this is a very convenient way of migrating a database.

First, it’s weird but the PDB administrator of the source DB must have the CREATE PLUGGABLE DATABASE privilege:

su - oracle
. oraenv <<< CPROD19
sqlplus / as sysdba
alter session set container=PRODDB01;
grant create pluggable database to pdbadmin;
exit

On the DB System, let’s create a new TNS entry for the 19c PDB:

ssh dbs-04-tst
su - oracle
. oraenv <<< CTEST26
vi $ORACLE_HOME/network/admin/tnsnames.ora

...
PRODDB01 =
  (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = dbioda01.dbi-lab.ch)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = proddb01.dbi-lab.ch)
    )
  )

On the target CDB, create a new database link to the source database:

CREATE DATABASE LINK PRODDB01 CONNECT TO PDBADMIN IDENTIFIED BY "*********"  USING 'PRODDB01';

select count(*) from dual@PRODDB01;
  COUNT(*)
----------
         1

Now let’s copy the source PDB under a new name on the 26ai container:

create pluggable database MIG26DBLINK from PRODDB01@PRODDB01;
Pluggable database created.

alter pluggable database MIG26DBLINK open;

Opening this PDB will take some minutes because it automatically triggers the upgrade from 19c to 26ai:

tail -n 15 --f /u01/app/oracle/diag/rdbms/ctest26_s1/CTEST26/trace/alert_CTEST26.log 
...
MIG26DBLINK(3):Starting Upgrade on PDB Open
2026-01-12T10:57:49.606651+01:00
MIG26DBLINK(3):alter pluggable database application APP$CDB$CATALOG begin install '19.0.0.0.0' on error capture
MIG26DBLINK(3):Completed: alter pluggable database application APP$CDB$CATALOG begin install '19.0.0.0.0' on error capture
MIG26DBLINK(3):alter pluggable database application APP$CDB$CATALOG end install '19.0.0.0.0'
MIG26DBLINK(3):Completed: alter pluggable database application APP$CDB$CATALOG end install '19.0.0.0.0'
MIG26DBLINK(3):alter pluggable database application APP$CDB$CATALOG begin upgrade
  '19.0.0.0.0' to '23.0.0.0.0.partial' on error capture
MIG26DBLINK(3):Completed: alter pluggable database application APP$CDB$CATALOG begin upgrade
  '19.0.0.0.0' to '23.0.0.0.0.partial' on error capture
...
MIG26DBLINK(3):SERVER COMPONENT id=CATJAVA: status=UPGRADED, version=23.26.0.0.0, timestamp=2026-01-12 11:09:54 Container=MIG26DBLINK Id=3
2026-01-12T11:09:58.200636+01:00
MIG26DBLINK(3):Resize operation completed for file# 19, fname +DATA/CTEST26_S1/482EE16D86417106E063F700240A6555/DATAFILE/undotbs1.294.1222340161, old size 450560K, new size 455680K
2026-01-12T11:09:59.496448+01:00
MIG26DBLINK(3):Resize operation completed for file# 19, fname +DATA/CTEST26_S1/482EE16D86417106E063F700240A6555/DATAFILE/undotbs1.294.1222340161, old size 455680K, new size 460800K
2026-01-12T11:10:26.701609+01:00
MIG26DBLINK(3):oracle :
MIG26DBLINK(3):SERVER COMPONENT id=XDB: status=UPGRADED, version=23.26.0.0.0, timestamp=2026-01-12 11:10:26 Container=MIG26DBLINK Id=3
2026-01-12T11:10:36.378304+01:00
MIG26DBLINK(3):Resize operation completed for file# 19, fname +DATA/CTEST26_S1/482EE16D86417106E063F700240A6555/DATAFILE/undotbs1.294.1222340161, old size 460800K, new size 465920K
2026-01-12T11:10:45.077998+01:00
MIG26DBLINK(3):Resize operation completed for file# 19, fname +DATA/CTEST26_S1/482EE16D86417106E063F700240A6555/DATAFILE/undotbs1.294.1222340161, old size 465920K, new size 471040K
...
MIG26DBLINK(3):***************************************************************
MIG26DBLINK(3):WARNING: Pluggable Database MIG26DBLINK with pdb id - 3 is
MIG26DBLINK(3):         altered with errors or warnings. Please look into
MIG26DBLINK(3):         PDB_PLUG_IN_VIOLATIONS view for more details.
MIG26DBLINK(3):***************************************************************
MIG26DBLINK(3):--ATTENTION--
MIG26DBLINK(3):Errors reported while opening PDB (ContainerId: 3) and have been recorded in pdb_alert$ table.
MIG26DBLINK(3) Error Violation: SQL Patch, Cause: '23.26.0.0.0 Release_Update 2509270520' is installed in the CDB but no release updates are installed in the PDB, Action: Call datapatch to install in the PDB or the CDB
2026-01-12T11:13:31.632629+01:00
MIG26DBLINK(3):Opening pdb with no Resource Manager plan active
Violations: Type: 1, Count: 1
Violations: Type: 2, Count: 2
Completed: Pluggable database MIG26DBLINK opened read write
Completed: alter pluggable database MIG26DBLINK open

After a couple of minutes, the PDB is opened with errors:

Warning: PDB altered with errors.
exit

Let’s apply datapatch on this very PDB:

$ORACLE_HOME/OPatch/datapatch -pdbs MIG26DBLINK
SQL Patching tool version 23.26.0.0.0 Lim on Mon Jan 12 11:14:55 2026
Copyright (c) 2012, 2025, Oracle.  All rights reserved.

Log file for this invocation: /u01/app/oracle/product/23.0.0.0/dbhome_1/cfgtoollogs/sqlpatch/sqlpatch_sid_CTEST26_ts_2026_01_12_11_14_55_pid_5074/sqlpatch_invocation.log

Connecting to database...OK
Gathering database info...done

Note:  Datapatch will only apply or rollback SQL fixes for PDBs
       that are in an open state, no patches will be applied to closed PDBs.
       Please refer to Note: Datapatch: Database 12c Post Patch SQL Automation
       (Doc ID 1585822.1)

Bootstrapping registry and package to current versions...done
Determining current state...done

Current state of interim SQL patches:
  No interim patches found

Current state of release update SQL patches:
  Binary registry:
    23.26.0.0.0 Release_Update 250927052030: Installed
  PDB MIG26DBLINK:
    Applied 23.26.0.0.0 Release_Update 250927052030 successfully

Adding patches to installation queue and performing prereq checks...done
Installation queue:
  For the following PDBs: MIG26DBLINK
    No interim patches need to be rolled back
    No release update patches need to be installed
    No interim patches need to be applied

Bypass install queue:
  For the following PDBs: MIG26DBLINK
    No interim rollbacks will bypass install
    Patch 38404116 (Database Release Update : 23.26.0.0.0 (38404116) Gold Image): will bypass install
      Apply from 23.26.0.0.0 Release_Update 250927052030 to 23.26.0.0.0 Release_Update 250927052030
    No interim applys will bypass install


Installation queue after removing bypass entries...
Installation queue:
  For the following PDBs: MIG26DBLINK
    No interim patches need to be rolled back
    No release update patches need to be installed
    No interim patches need to be applied


Processing bypass install queue:
  Patch 38404116 apply (pdb MIG26DBLINK): SUCCESS (bypass_install)

SQL Patching tool complete on Mon Jan 12 11:15:03 2026

Everything is fine, now let’s close and open this PDB in normal mode:

sqlplus / as sysdba
show pdbs

    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 3 MIG26DBLINK			  READ WRITE YES
	 4 MIG26DTPUMP			  READ WRITE NO

alter pluggable database MIG26DBLINK close immediate;
alter pluggable database MIG26DBLINK open;
alter pluggable database MIG26DBLINK save state;

show pdbs

    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 3 MIG26DBLINK			  READ WRITE NO
	 4 MIG26DTPUMP			  READ WRITE NO

Let’s do a quick data check:

sqlplus / as sysdba
alter session set container=MIG26DBLINK;
select start_date from dbi.consultants where name like 'DUB%';
START_DAT
---------
04-SEP-17

exit

Database is ready to use.

Pros & cons

  • + Maybe the easiest way of migrating a PDB
  • + Keep the source database untouched
  • + Rather fast
  • + No downtime of the source database
  • – Need to apply datapatch

Migration using unplug/plug features

If the source database is a PDB, it can be unplugged and plugged back to another container. This is how multitenant architecture was presented when it first came to 12cR1.

Let’s unplug the source PDB:

su - oracle
. oraenv <<< CPROD19
sqlplus / as sysdba
alter pluggable database PRODDB01 close immediate;
Pluggable database altered.

alter pluggable database PRODDB01 unplug into '/backup/dumps/PRODDB01.xml';
Pluggable database altered.

exit

Now let’s plug this PDB to the new 26ai container:

ssh root@dbs-04-tst
su - oracle
. oraenv <<< CTEST26

sqlplus / as sysdba

show pdbs

    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 3 MIG26DBLINK			  READ WRITE NO
	 4 MIG26DTPUMP			  READ WRITE NO

create pluggable database MIG26REPLUG using '/backup/dumps/PRODDB01.xml' COPY;
create pluggable database MIG26REPLUG using '/backup/dumps/PRODDB01.xml' COPY
*
ERROR at line 1:
ORA-19505: failed to identify file
"+DATA/CPROD19_S1/450AA2873245B6F5E063F100240AC35A/DATAFILE/system.302.122233608
1"
ORA-17503: ksfdopn:2 Failed to open file
+DATA/CPROD19_S1/450AA2873245B6F5E063F100240AC35A/DATAFILE/system.302.1222336081
ORA-15260: permission denied on ASM disk group
Help: https://docs.oracle.com/error-help/db/ora-19505/

Files from the source database are not readable by this DB System. Let’s change the permission on these files from the Bare Metal ASM instance:

exit
exit
exit
su - grid

asmcmd ls -lt +DATA/CPROD19_S1/450AA2873245B6F5E063F100240AC35A/DATAFILE/* --permission
Type      Redund  Striped  Time             Sys  User                                     Group  Permission  Name
DATAFILE  MIRROR  COARSE   JAN 12 11:00:00  Y    oracle@e7d9d36f6b157fdabf89026bcf48d757          rw-------  USERS.297.1222336081
DATAFILE  MIRROR  COARSE   JAN 12 11:00:00  Y    oracle@e7d9d36f6b157fdabf89026bcf48d757          rw-------  UNDOTBS1.306.1222336081
DATAFILE  MIRROR  COARSE   JAN 12 11:00:00  Y    oracle@e7d9d36f6b157fdabf89026bcf48d757          rw-------  SYSTEM.302.1222336081
DATAFILE  MIRROR  COARSE   JAN 12 11:00:00  Y    oracle@e7d9d36f6b157fdabf89026bcf48d757          rw-------  SYSAUX.305.1222336081

asmcmd ls -lt +DATA/CTEST26_S1/DATAFILE/* --permission
Type      Redund  Striped  Time             Sys  User                                     Group  Permission  Name
DATAFILE  MIRROR  COARSE   JAN 12 10:00:00  Y    oracle@b94b488f82b1cf5cbf58f54162aafac0          rw-------  USERS.299.1222339507
DATAFILE  MIRROR  COARSE   JAN 12 10:00:00  Y    oracle@b94b488f82b1cf5cbf58f54162aafac0          rw-------  UNDOTBS1.693.1222338993
DATAFILE  MIRROR  COARSE   JAN 12 10:00:00  Y    oracle@b94b488f82b1cf5cbf58f54162aafac0          rw-------  SYSTEM.906.1222338951
DATAFILE  MIRROR  COARSE   JAN 12 10:00:00  Y    oracle@b94b488f82b1cf5cbf58f54162aafac0          rw-------  SYSAUX.832.1222338987

asmcmd chmod a+r +DATA/CPROD19_S1/450AA2873245B6F5E063F100240AC35A/DATAFILE/*
asmcmd ls -lt +DATA/CPROD19_S1/450AA2873245B6F5E063F100240AC35A/DATAFILE/* --permission
Type      Redund  Striped  Time             Sys  User                                     Group  Permission  Name
DATAFILE  MIRROR  COARSE   JAN 12 11:00:00  Y    oracle@e7d9d36f6b157fdabf89026bcf48d757          rw-r--r--  USERS.297.1222342153
DATAFILE  MIRROR  COARSE   JAN 12 11:00:00  Y    oracle@e7d9d36f6b157fdabf89026bcf48d757          rw-r--r--  UNDOTBS1.301.1222341995
DATAFILE  MIRROR  COARSE   JAN 12 11:00:00  Y    oracle@e7d9d36f6b157fdabf89026bcf48d757          rw-r--r--  SYSTEM.305.1222341995
DATAFILE  MIRROR  COARSE   JAN 12 11:00:00  Y    oracle@e7d9d36f6b157fdabf89026bcf48d757          rw-r--r--  SYSAUX.302.1222341995

exit

ssh root@dbs-04-tst
su - oracle
. oraenv <<< CTEST26

sqlplus / as sysdba

create pluggable database MIG26REPLUG using '/backup/dumps/PRODDB01.xml' COPY;
Pluggable database created.

show pdbs

    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 3 MIG26DBLINK			  READ WRITE NO
	 4 MIG26DTPUMP			  READ WRITE NO
	 6 MIG26REPLUG			  MOUNTED

alter pluggable database MIG26REPLUG open;

It will also take a couple of minutes for this upgrade to 26ai. You will see corresponding traces in the alert.log file of the 26ai container:

tail -f /u01/app/oracle/diag/rdbms/ctest26_s1/CTEST26/trace/alert_CTEST26.log
...
2026-01-12T11:34:21.075364+01:00
MIG26REPLUG(6):Starting Upgrade on PDB Open
...
MIG26REPLUG(6):***************************************************************
MIG26REPLUG(6):WARNING: Pluggable Database MIG26REPLUG with pdb id - 6 is
MIG26REPLUG(6):         altered with errors or warnings. Please look into
MIG26REPLUG(6):         PDB_PLUG_IN_VIOLATIONS view for more details.
MIG26REPLUG(6):***************************************************************
MIG26REPLUG(6):--ATTENTION--
MIG26REPLUG(6):Errors reported while opening PDB (ContainerId: 6) and have been recorded in pdb_alert$ table.
MIG26REPLUG(6) Error Violation: SQL Patch, Cause: '23.26.0.0.0 Release_Update 2509270520' is installed in the CDB but no release updates are installed in the PDB, Action: Call datapatch to install in the PDB or the CDB
2026-01-12T11:49:56.836062+01:00
MIG26REPLUG(6):Opening pdb with no Resource Manager plan active
Violations: Type: 1, Count: 1
Violations: Type: 2, Count: 1
Completed: Pluggable database MIG26REPLUG opened read write
Completed: alter pluggable database MIG26REPLUG open

Let’s have a look at my PDBs and apply the datapatch on MIG26REPLUG:

show pdbs
    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 3 MIG26DBLINK			  READ WRITE NO
	 4 MIG26DTPUMP			  READ WRITE NO
	 6 MIG26REPLUG			  READ WRITE YES

exit

$ORACLE_HOME/OPatch/datapatch -pdbs MIG26REPLUG

SQL Patching tool version 23.26.0.0.0 Lim on Mon Jan 12 11:51:42 2026
Copyright (c) 2012, 2025, Oracle.  All rights reserved.

Log file for this invocation: /u01/app/oracle/product/23.0.0.0/dbhome_1/cfgtoollogs/sqlpatch/sqlpatch_sid_CTEST26_ts_2026_01_12_11_51_42_pid_24026/sqlpatch_invocation.log

Connecting to database...OK
Gathering database info...done

Note:  Datapatch will only apply or rollback SQL fixes for PDBs
       that are in an open state, no patches will be applied to closed PDBs.
       Please refer to Note: Datapatch: Database 12c Post Patch SQL Automation
       (Doc ID 1585822.1)

Bootstrapping registry and package to current versions...done
Determining current state...done

Current state of interim SQL patches:
  No interim patches found

Current state of release update SQL patches:
  Binary registry:
    23.26.0.0.0 Release_Update 250927052030: Installed
  PDB MIG26REPLUG:
    Applied 23.26.0.0.0 Release_Update 250927052030 successfully

Adding patches to installation queue and performing prereq checks...done
Installation queue:
  For the following PDBs: MIG26REPLUG
    No interim patches need to be rolled back
    No release update patches need to be installed
    No interim patches need to be applied

Bypass install queue:
  For the following PDBs: MIG26REPLUG
    No interim rollbacks will bypass install
    Patch 38404116 (Database Release Update : 23.26.0.0.0 (38404116) Gold Image): will bypass install
      Apply from 23.26.0.0.0 Release_Update 250927052030 to 23.26.0.0.0 Release_Update 250927052030
    No interim applys will bypass install


Installation queue after removing bypass entries...
Installation queue:
  For the following PDBs: MIG26REPLUG
    No interim patches need to be rolled back
    No release update patches need to be installed
    No interim patches need to be applied


Processing bypass install queue:
  Patch 38404116 apply (pdb MIG26REPLUG): SUCCESS (bypass_install)

SQL Patching tool complete on Mon Jan 12 11:51:50 2026

Now let’s restart the PDB in normal mode:

sqlplus / as sysdba

alter pluggable database MIG26REPLUG close immediate;
alter pluggable database MIG26REPLUG open;
alter pluggable database MIG26REPLUG save state;

show pdbs

    CON_ID CON_NAME			  OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
	 2 PDB$SEED			  READ ONLY  NO
	 3 MIG26DBLINK			  READ WRITE NO
	 4 MIG26DTPUMP			  READ WRITE NO
	 6 MIG26REPLUG			  READ WRITE NO

This PDB is now running on 26ai.

Let’s check my consultants table:

alter session set container=MIG26REPLUG;
select start_date from dbi.consultants where name like 'DUB%';
START_DAT
---------
04-SEP-17

exit

Pros & cons

  • + Easy migration
  • + Preserve source files with the copy option
  • + Rather fast
  • – Need a downtime of the source PDB
  • – Reuse of source database is only possible by unplugging and plugging back the PDB with the xml file

Conclusion

There are multiple ways of migrating to 26ai. There is quite a lot of new features coming with 26ai. You will use them or not, but trying to migrate to this version is something to start thinking about in 2026.

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Jérôme Dubar