Migrating an Oracle 19c database on Linux to PostgreSQL on Windows involves several steps. This is a detailed step-by-step process, but ensure you understand both Oracle and PostgreSQL environments before proceeding. This guide uses tools such as ora2pg to assist with the migration.
Prerequisites:
Oracle 19c installed on Linux
PostgreSQL installed on Windows
Network access between the Linux and Windows servers
ora2pg installed on Linux
Step 1: Install ora2pg on the Linux Server
ora2pg is a tool used to migrate Oracle schemas to PostgreSQL.
Install dependencies:
bash
sudo apt-get install -y build-essential libaio1 libaio-dev
Download and install ora2pg:
bash
sudo apt-get install ora2pg
Verify installation:
bash
ora2pg --version
Step 2: Configure ora2pg for Oracle 19c
Create a directory for ora2pg project files:
bash
mkdir ~/ora2pg_project cd ~/ora2pg_project
Copy the default ora2pg configuration file:
bash
cp /etc/ora2pg/ora2pg.conf ./ora2pg.conf
Edit the ora2pg.conf file:
bash
nano ora2pg.conf
Update the following settings:
ini
ORACLE_HOME /path/to/oracle/home ORACLE_DSN dbi:Oracle:host=your_oracle_host;sid=your_oracle_sid ORACLE_USER your_oracle_user ORACLE_PWD your_oracle_password PG_DSN dbi:Pg:host=your_postgres_host;port=5432;dbname=your_postgres_db PG_USER your_postgres_user PG_PWD your_postgres_password
Step 3: Export Oracle Schema using ora2pg
Perform an initial export of your Oracle schema:
bash
ora2pg -t SHOW_VERSION
Test the schema export:
bash
ora2pg -t SCHEMA -o schema.sql -b ./output
This will export the Oracle schema into PostgreSQL compatible SQL.
Verify the output in the ./output directory and modify it if necessary.
Step 4: Export Oracle Data
Export data from Oracle:
bash
ora2pg -t COPY -o data.sql -b ./output
Check for any errors or warnings in the export log files.
Step 5: Set up PostgreSQL on Windows
Install PostgreSQL on Windows: You can download and install PostgreSQL from here.
Create a new PostgreSQL database:
sql
CREATE DATABASE your_postgres_db;
Create necessary users:
sql
CREATE USER your_postgres_user WITH PASSWORD 'your_postgres_password'; GRANT ALL PRIVILEGES ON DATABASE your_postgres_db TO your_postgres_user;
Step 6: Transfer the Export Files from Linux to Windows
Transfer the schema and data files (from ./output directory) from the Linux server to the Windows machine. You can use tools like scp or file transfer utilities.
Example using scp:
bash
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scp ~/ora2pg_project/output/schema.sql your_windows_user@your_windows_ip:/path/to/destination scp ~/ora2pg_project/output/data.sql your_windows_user@your_windows_ip:/path/to/destination
Step 7: Import into PostgreSQL
On the Windows machine, connect to your PostgreSQL instance:
bash
psql -h localhost -U your_postgres_user -d your_postgres_db
Import the schema:
bash
\i '/path/to/schema.sql';
Import the data:
bash
\i '/path/to/data.sql';
Step 8: Verify Migration
Check table structure:
sql
\dt
Check the data:
sql
SELECT * FROM your_table LIMIT 10;
Verify that all your tables, constraints, and data are successfully imported.
Step 9: Post-Migration Tasks
Fix any compatibility issues: Review logs, check for data types or functions in PostgreSQL that behave differently than in Oracle.
Migrate Stored Procedures: Manually convert Oracle PL/SQL procedures to PostgreSQL PL/pgSQL.
Test thoroughly: Run application tests to ensure everything works correctly in PostgreSQL.
Step 10: Backup and Optimization
Backup PostgreSQL database:
bash
pg_dump -U your_postgres_user -F c -b -v -f "backup_filename.backup" your_postgres_db
Optimize: Run VACUUM and analyze performance tuning for PostgreSQL.
bash
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VACUUM FULL; ANALYZE;
This is a basic guide for migration. Complex databases may require more fine-tuning and customization during the migration process. Be sure to test everything thoroughly after migration.
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