What is Data instantiation
Before data replication can start, the target database must have a copy of the database objects that are going to be replicated. It is also necessary that the data for the objects to be replicated are completely in sync at the point at which the replication starts. This is done with the Oracle SCN. By using the Oracle SCN it is guaranteed that no transactions are lost during the replication setup.
The Oracle SCN is captured to enable to pick a snapshot of the data at a point in time. This Oracle SCN is then used in two ways:
- Everything before the SCN must be copied manually. This is called Data Instantiation and is done in this example through Oracle DataPump.
- Everything after the SCN is replicated by the replication tool (in this case Dbvisit Replicate)
Running DataPump
1. On the target server (dbv02), ensure that the OE schema is clean. Run the following script to ensure that there are no OE objects. If there are then the DataPump script will fail
sqlplus oe/oe SQL> @/home/oracle/swingbench/sql/soedgdrop2.sql
2. On the target server (dbv02), setup the database link as user system
sqlplus system/oracle SQL> CREATE public DATABASE LINK ttorcl_src CONNECT TO system IDENTIFIED BY oracle USING 'ttorcl_src';
This database link is needed for the Datapump script that is created as APPLY.sh. The content of datapump script APPLY.sh is similar to:
impdp SYSTEM/oracle@ttorcl_trg table_exists_action=TRUNCATE network_link=ttorcl_src directory=DATA_PUMP_DIR flashback_scn=14415748 tables=OE.ADDRESSES,OE.CARD_DETAILS,OE.CUSTOMERS,OE.INVENTORIES,OE.LOGON,OE.ORDERENTRY_METADATA,OE.ORDERS,OE.ORDER_ITEMS,OE.PRODUCT_DESCRIPTIONS,OE.PRODUCT_INFORMATION,OE.WAREHOUSES logfile=OE_WAREHOUSES.log JOB_NAME=DP_dbvrep_orcl_0001
The flashback_scn number (in this case 14415748) determines the consistency point as to where the data will be loaded to. All data prior to this SCN will be loaded using the above DataPump script. All data past this SCN will be replicated using Dbvisit Replicate.
3. On the source server (dbv01) start the APPLY.sh script
$ ./APPLY.sh Import: Release 11.2.0.2.0 - Production on Sat Dec 28 19:55:26 2013 Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - Production With the Partitioning, OLAP, Data Mining and Real Application Testing options Starting "SYSTEM"."DP_DBVREP_ORCL_0001": SYSTEM/********@ttorcl_trg table_exists_action=TRUNCATE network_link=ttorcl_src directory=DATA_PUMP_DIR flashback_scn=14491671 tables=OE.ADDRESSES,OE.CARD_DETAILS,OE.CUSTOMERS,OE.INVENTORIES,OE.LOGON,OE.ORDERENTRY_METADATA,OE.ORDERS,OE.ORDER_ITEMS,OE.PRODUCT_DESCRIPTIONS,OE.PRODUCT_INFORMATION,OE.WAREHOUSES logfile=OE_WAREHOUSES.log JOB_NAME=DP_dbvrep_orcl_0001 Estimate in progress using BLOCKS method... Processing object type TABLE_EXPORT/TABLE/TABLE_DATA Total estimation using BLOCKS method: 1.008 GB Processing object type TABLE_EXPORT/TABLE/TABLE . . imported "OE"."ORDER_ITEMS" 4290023 rows . . imported "OE"."INVENTORIES" 900632 rows . . imported "OE"."ORDERS" 1429790 rows . . imported "OE"."ADDRESSES" 1500000 rows . . imported "OE"."CUSTOMERS" 1000000 rows . . imported "OE"."CARD_DETAILS" 1500000 rows . . imported "OE"."LOGON" 2382984 rows . . imported "OE"."PRODUCT_DESCRIPTIONS" 1000 rows . . imported "OE"."PRODUCT_INFORMATION" 1000 rows . . imported "OE"."ORDERENTRY_METADATA" 4 rows . . imported "OE"."WAREHOUSES" 1000 rows Processing object type TABLE_EXPORT/TABLE/GRANT/OWNER_GRANT/OBJECT_GRANT Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/CONSTRAINT Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/REF_CONSTRAINT Processing object type TABLE_EXPORT/TABLE/INDEX/FUNCTIONAL_AND_BITMAP/INDEX Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/FUNCTIONAL_AND_BITMAP/INDEX_STATISTICS Job "SYSTEM"."DP_DBVREP_ORCL_0001" successfully completed at 20:20:50 [oracle@source dbvrep_orcl]$
During the import of the data, the archiver will become stuck because there will not be enough space.
Run the following script a few times on the target server (dbv02) to ensure that the flash recovery area does not fill up and pause the import:
/usr/local/bin/del_arch.sh orcl 0
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