{ "date": "2016-11-11T05:19:32", "slug": "oracle-12cr2-pluggable-database-relocation", "link": "https://www.dbi-services.com/blog/oracle-12cr2-pluggable-database-relocation/", "title": { "rendered": "Oracle 12cR2: Pluggable database relocation" }, "content": { "rendered": "

By Franck Pachot

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\nHere is, in my opinion, the most beautiful feature of the multitenant architecture. You know how I love Transportable Tablespaces. But here:

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Standard Edition

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I am in Standard Edition here in both source and target, no option required for this:

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\nSQL*Plus: Release 12.2.0.1.0 Production on Thu Nov 10 13:40:05 2016\nCopyright (c) 1982, 2016, Oracle.  All rights reserved.\n \nConnected to:\nOracle Database 12c Standard Edition Release 12.2.0.1.0 - 64bit Production\n
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Source: PDB1 on CDB1

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On server opc1 I have a container database CDB1 with one pluggable database PDB1 where I create a new table:

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\n23:40:20 (opc1)CDB1 SQL>alter session set container=PDB1;\nSession altered.\n23:40:20 (opc1)CDB1 SQL>create table DEMO as select current_timestamp insert_timestamp,instance_name from v$instance;\nTable created.\n23:40:21 (opc1)CDB1 SQL>insert into DEMO select current_timestamp,instance_name from v$instance;\n1 row created.\n23:40:21 (opc1)CDB1 SQL>select * from DEMO;\n \nINSERT_TIMESTAMP                    INSTANCE_NAME\n----------------------------------- ----------------\n10-NOV-16 11.40.20.902761 PM +00:00 CDB1\n10-NOV-16 11.40.21.966815 PM +00:00 CDB1\n
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Export encryption key

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I’m in Oracle Public Cloud where tablespaces are encrypted. To ship a pluggable database I must export the keys. Here is the query to get them:

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\n23:40:23 (opc1)CDB1 SQL>select key_id from v$encryption_keys where creator_pdbname='PDB1';\n \nKEY_ID\n------------------------------------------------------------------------------\nAWlnBaUXG0/gv4evS9Ywu8EAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\n
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And I can filter with this query to export it:

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\n23:40:23 (opc1)CDB1 SQL>administer key management export encryption keys with secret \"oracle\" to '/tmp/cdb2pdb1.p12' identified by \"Ach1z0#d\" with identifier in (select key_id from v$encryption_keys where creator_pdbname='PDB1');\nadminister key management export encryption keys with secret \"oracle\" to '/tmp/cdb2pdb1.p12' identified by \"Ach1z0#d\" with identifier in (select key_id from v$encryption_keys where creator_pdbname='PDB1')\n*\nERROR at line 1:\nORA-28417: password-based keystore is not open\n
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I can’t do that with auto-login wallet.

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\n23:40:23 (opc1)CDB1 SQL>select wrl_type,wrl_parameter,wallet_type from v$encryption_wallet;\n \nWRL_TYPE WRL_PARAMETER                          WALLET_TY\n-------- -------------------------------------- ---------\nFILE     /u01/app/oracle/admin/CDB1/tde_wallet/ AUTOLOGIN\n
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Let’s open the wallet with password:

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\n23:40:23 (opc1)CDB1 SQL>administer key management set keystore close;\nkeystore altered.\n23:40:23 (opc1)CDB1 SQL>administer key management set keystore open identified by \"Ach1z0#d\";\nkeystore altered.\n23:40:23 (opc1)CDB1 SQL>select wrl_type,wrl_parameter,wallet_type from v$encryption_wallet;\n \nWRL_TYPE WRL_PARAMETER                          WALLET_TY\n-------- -------------------------------------- ---------\nFILE     /u01/app/oracle/admin/CDB1/tde_wallet/ PASSWORD\n
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and re-try my export:

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\n23:40:23 (opc1)CDB1 SQL>administer key management export encryption keys with secret \"oracle\" to '/tmp/cdb2pdb1.p12' identified by \"Ach1z0#d\" with identifier in (select key_id from v$encryption_keys where creator_pdbname='PDB1');\nkeystore altered.\n
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This file must be copied to the destination server. I did it with scp. You can also use dbms_file_transfer as you will need a database link anyway for the remote clone.

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Import encryption key

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On the destination server, where I have no CDB (I’m limited to one PDB here without the multitenant option)

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\n23:40:31 (opc2)CDB2 SQL>show pdbs\n \n    CON_ID CON_NAME                       OPEN MODE  RESTRICTED\n---------- ------------------------------ ---------- ----------\n         2 PDB$SEED                       READ ONLY  NO\n
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I have to import the encryption key:

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\n23:40:31 (opc2)CDB2 SQL>administer key management set keystore open identified by \"Ach1z0#d\";\nkeystore altered.\n \n23:40:31 (opc2)CDB2 SQL>administer key management import encryption keys with secret \"oracle\" from '/tmp/cdb2pdb1.p12' identified by \"Ach1z0#d\";\nkeystore altered.\n
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I’m now ready to relocate my PDB as I’m sure I’ll be ready to open it.

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Database link

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The remote clone is done through a DB link. I’ve a TNS entry named CDB1:

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\n23:40:31 (opc2)CDB2 SQL>select dbms_tns.resolve_tnsname('CDB1') from dual;\n \nDBMS_TNS.RESOLVE_TNSNAME('CDB1')\n--------------------------------------------------------------------------------\n(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=opc1)(PORT=1521))(CONNECT_DAT\nA=(SERVER=DEDICATED)(SERVICE_NAME=CDB1.opcoct.oraclecloud.internal)(CID=(PROGRAM\n=oracle)(HOST=SE222.compute-opcoct.oraclecloud.internal)(USER=oracle))))\n \n23:40:31 (opc2)CDB2 SQL>create database link CDB1 connect to C##DBA identified by oracle using 'CDB1';\nDatabase link created.\n
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DML on source

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In order to show that the source doesn’t have to be read only as in previous release, I’m running the following inserts every 5 minutes:

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\n23:40:44 (opc1)CDB1 SQL>commit;\nCommit complete.\n23:40:44 (opc1)CDB1 SQL>insert into DEMO select current_timestamp,instance_name from v$instance;\n1 row created.\n23:40:44 (opc1)CDB1 SQL>select * from DEMO;\n \nINSERT_TIMESTAMP                    INSTANCE_NAME\n----------------------------------- ----------------\n10-NOV-16 11.40.20.902761 PM +00:00 CDB1\n10-NOV-16 11.40.21.966815 PM +00:00 CDB1\n10-NOV-16 11.40.29.136529 PM +00:00 CDB1\n10-NOV-16 11.40.34.214467 PM +00:00 CDB1\n10-NOV-16 11.40.39.304515 PM +00:00 CDB1\n10-NOV-16 11.40.44.376796 PM +00:00 CDB1\n6 rows selected.\n
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PDB remote clone

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Here is the syntax.
\nI need to provide the masterkey of the source wallet.
\nThe RELOCATE is this new feature where the source PDB will be relocated to the destination when the clone is opened.

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\n23:40:48 (opc2)CDB2 SQL>create pluggable database PDB1 from PDB1@CDB1 keystore identified by \"Ach1z0#d\" relocate;\nPluggable database created.\n23:41:08 (opc2)CDB2 SQL>\n
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It took some time, shipping the datafiles through the DB link, but this is online.
\nI was still inserting during this time:

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\n23:41:04 (opc1)CDB1 SQL>select * from DEMO;\n \nINSERT_TIMESTAMP                    INSTANCE_NAME\n----------------------------------- ----------------\n10-NOV-16 11.40.20.902761 PM +00:00 CDB1\n10-NOV-16 11.40.21.966815 PM +00:00 CDB1\n10-NOV-16 11.40.29.136529 PM +00:00 CDB1\n10-NOV-16 11.40.34.214467 PM +00:00 CDB1\n10-NOV-16 11.40.39.304515 PM +00:00 CDB1\n10-NOV-16 11.40.44.376796 PM +00:00 CDB1\n10-NOV-16 11.40.49.454661 PM +00:00 CDB1\n10-NOV-16 11.40.54.532699 PM +00:00 CDB1\n10-NOV-16 11.40.59.614745 PM +00:00 CDB1\n10-NOV-16 11.41.04.692784 PM +00:00 CDB1\n \n10 rows selected.\n
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Note that you need to be in ARCHIVELOG and LOCAL UNDO to be able to do this because syncronisation will be made by media recovery when we open the clone.

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Open the clone

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Now, the theory is that when we open the clone, DML is quiesced on source during the recovery of the target and sessions can continue on the target once opened.

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\n23:41:09 (opc2)CDB2 SQL>alter pluggable database PDB1 open;\nalter pluggable database PDB1 open\n*\nERROR at line 1:\nORA-00060: deadlock detected while waiting for resource\n23:41:26 (opc2)CDB2 SQL>\n
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Bad luck. Every time I tested this scenario, the first open after the relocate fails in deadlock and the session on the source crashes:

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\n23:41:09 (opc1)CDB1 SQL>select * from DEMO;\n \nINSERT_TIMESTAMP                    INSTANCE_NAME\n----------------------------------- ----------------\n10-NOV-16 11.40.20.902761 PM +00:00 CDB1\n10-NOV-16 11.40.21.966815 PM +00:00 CDB1\n10-NOV-16 11.40.29.136529 PM +00:00 CDB1\n10-NOV-16 11.40.34.214467 PM +00:00 CDB1\n10-NOV-16 11.40.39.304515 PM +00:00 CDB1\n10-NOV-16 11.40.44.376796 PM +00:00 CDB1\n10-NOV-16 11.40.49.454661 PM +00:00 CDB1\n10-NOV-16 11.40.54.532699 PM +00:00 CDB1\n10-NOV-16 11.40.59.614745 PM +00:00 CDB1\n10-NOV-16 11.41.04.692784 PM +00:00 CDB1\n10-NOV-16 11.41.09.773300 PM +00:00 CDB1\n \n11 rows selected.\n \n23:41:14 (opc1)CDB1 SQL> commit;\nERROR:\nORA-03114: not connected to ORACLE\n
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It’s a good occasion to look at the traces.
\nWe can see some messages about the recovery:

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\n*** 2016-11-10T23:41:12.660402+00:00 (PDB1(3))\nMedia Recovery Log /u03/app/oracle/fast_recovery_area/CDB1/foreign_archivelog/PDB1/2016_11_10/o1_mf_1_24_2025109931_.arc\nLog read is SYNCHRONOUS though disk_asynch_io is enabled!\n
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Those FOREIGN ARCHIVED LOG is a new type of file that you will see in the FRA in 12.2.

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So I lost my session on source and now if I try again it works:

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\n23:42:20 (opc2)CDB2 SQL>alter pluggable database PDB1 open;\nPluggable database altered.\n23:42:24 (opc2)CDB2 SQL>select * from DEMO;\n \nINSERT_TIMESTAMP                    INSTANCE_NAME\n----------------------------------- ----------------\n10-NOV-16 11.40.20.902761 PM +00:00 CDB1\n10-NOV-16 11.40.21.966815 PM +00:00 CDB1\n10-NOV-16 11.40.29.136529 PM +00:00 CDB1\n10-NOV-16 11.40.34.214467 PM +00:00 CDB1\n10-NOV-16 11.40.39.304515 PM +00:00 CDB1\n10-NOV-16 11.40.44.376796 PM +00:00 CDB1\n10-NOV-16 11.40.49.454661 PM +00:00 CDB1\n10-NOV-16 11.40.54.532699 PM +00:00 CDB1\n10-NOV-16 11.40.59.614745 PM +00:00 CDB1\n10-NOV-16 11.41.04.692784 PM +00:00 CDB1\n \n10 rows selected.\n
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All the inserts that were commited on the source are there.
\nEven with this deadlock bug (SR 3-13618219421), it’s the easiest and fastest way to migrate a database, with the minimum of downtime. Especially in Standard Edition where transportable tablespaces import is not enabled.
\nWithout the deadlock bug, the sessions on the source are supposed to be still running , only paused during the recovery, and then continue on the destination.

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