Extract and Replicat processes take care the data from the point of setup of the processes. To setup a replication using Goldengate, We need to make sure that existing data are properly copied from Source to Target and this is called Initial Load.
There are different types of Initial Load available in Oracle GoldenGate as well as a few possible methods outside the GoldenGate for performing data synchronization between Source and Target databases.
Initial Loading Methods:
- Using RMAN
- Oracle Export and Import (Data PUMP)
- Oracle Transportable Tablespace
- ETL Tools
- SQL Loader – Useful for heterogeneous environments.
GoldenGate Initial Loading Methods:
- File to Replicat
- File to Database Utility
- Direct Load
- Direct Bulk Load.
Oracle GoldenGate Direct Load: I will show in below example, how to load data using this method.
Create Initial Extract Load:
GGSCI (orclprd.localdomain as ggusr@orclprd) 24> VIEW PARAM EINIT1 extract EINIT1 SETENV (ORACLE_SID=ORCLPRD) USERIDALIAS GGUSR_ORCLPRD RMTHOST 192.168.56.20, MGRPORT 7809 RMTTASK REPLICAT, GROUP RINIT1 TABLE HR.*;
GGSCI (orclprd.localdomain as ggusr@orclprd) 16> ADD EXTRACT EINIT1 SOURCEISTABLE EXTRACT added.
Create Initial Load Replicate on Target:
GGSCI (orcl19c.localdomain) 7> view param RINIT1 REPLICAT RINIT1 SETENV (ORACLE_SID=ORCLPRD) USERIDALIAS GGUSR_ORCL MAP HR.*, TARGET HR1.*; GGSCI (orcl19c.localdomain) 8> ADD REPLICAT RINIT1 SPECIALRUN REPLICAT added.
Create All Objects (Tables/View) on Target Database. We may generate the table creation scripts from source database and execute on Target.
Start Extract Initial Load Process:
Note::: Don’t need to start the Replicat Process.
GGSCI (orclprd.localdomain) 2> start EINIT1
Sending START request to MANAGER ...
EXTRACT EINIT1 starting
GGSCI (orclprd.localdomain as ggusr@orclprd) 41> info EINIT1
EXTRACT EINIT1 Last Started 2023-11-27 23:20 Status RUNNING
Checkpoint Lag Not Available
Process ID 29612
Log Read Checkpoint Table HR.COUNTRIES
2023-11-27 23:20:20 Record 1
Task SOURCEISTABLE
GGSCI (orclprd.localdomain as ggusr@orclprd) 42> info EINIT1
EXTRACT EINIT1 Last Started 2023-11-27 23:20 Status RUNNING
Checkpoint Lag Not Available
Process ID 29612
Log Read Checkpoint Table HR.EMPLOYEES
2023-11-27 23:20:30 Record 1
Task SOURCEISTABLE
GGSCI (orclprd.localdomain) 4> !
info EINIT1
EXTRACT EINIT1 Last Started 2023-11-27 23:23 Status STOPPED
Checkpoint Lag Not Available
Log Read Checkpoint Table HR.REGIONS
2023-11-27 23:23:32 Record 4
Task SOURCEISTABLE
Validation on Target Side:
SQL> select name from v$database;
NAME
---------
ORCL
SQL> select count(*) from hr1.REGIONS;
COUNT(*)
----------
4
SQL> select count(*) from hr.EMPLOYEES;
COUNT(*)
----------
107
Note: We need to start extract and pump prior to the initial load starting to capture the changes while initial load is running.
GGSCI (orclprd.localdomain) 6> info EINIT1
EXTRACT EINIT1 Last Started 2023-11-27 23:23 Status STOPPED
Checkpoint Lag Not Available
Log Read Checkpoint Table HR.REGIONS
2023-11-27 23:23:32 Record 4
Task SOURCEISTABLE
