Database Modernization with Autohand Code

# Initialize database assessment
autohand init --database oracle --target postgresql

# Generate migration roadmap
autohand plan --target-version 15 --output db-roadmap.json

# Assessment includes:
# - Schema complexity analysis
# - Data volume and migration time
# - Application dependency mapping
# - Performance benchmarking

# Initialize schema migration
autohand init --database oracle --target postgresql

# Configure migration settings
autohand config --set preserve-data=true
autohand config --set generate-tests=true

# Execute schema migration
autohand migrate --phase schema-transformation

-- Before (Oracle)
CREATE TABLE employees (
    employee_id NUMBER(6) PRIMARY KEY,
    first_name VARCHAR2(20) NOT NULL,
    last_name VARCHAR2(25) NOT NULL,
    email VARCHAR2(25) UNIQUE NOT NULL,
    hire_date DATE DEFAULT SYSDATE,
    salary NUMBER(8,2) CHECK (salary > 0),
    department_id NUMBER(4) REFERENCES departments(department_id)
);

CREATE SEQUENCE emp_seq START WITH 1 INCREMENT BY 1;

CREATE OR REPLACE TRIGGER emp_trig
BEFORE INSERT ON employees
FOR EACH ROW
BEGIN
    :NEW.employee_id := emp_seq.NEXTVAL;
END;

-- After (PostgreSQL)
CREATE TABLE employees (
    employee_id BIGSERIAL PRIMARY KEY,
    first_name VARCHAR(20) NOT NULL,
    last_name VARCHAR(25) NOT NULL,
    email VARCHAR(25) UNIQUE NOT NULL,
    hire_date DATE DEFAULT CURRENT_DATE,
    salary NUMERIC(8,2) CHECK (salary > 0),
    department_id INTEGER REFERENCES departments(department_id)
);

-- Indexes for performance
CREATE INDEX idx_employees_department_id ON employees(department_id);
CREATE INDEX idx_employees_email ON employees(email);

# Initialize data migration
autohand migrate --init --data-transfer

# Configure data migration
autohand config --set batch-size=10000
autohand config --set parallel-workers=4

# Execute data migration
autohand migrate --phase data-transfer --validate-integrity

# Change Data Capture (CDC) example
import autohand

# Set up CDC pipeline
pipeline = autohand.CDC(
    source="oracle://prod",
    target="postgresql://prod",
    tables=["employees", "departments", "salaries"]
)

# Start real-time sync
pipeline.start_realtime_sync()

# Monitor migration progress
while pipeline.is_running():
    stats = pipeline.get_stats()
    print(f"Records migrated: {stats.records_migrated}")
    print(f"Throughput: {stats.throughput} records/sec")

-- Before (Oracle-specific)
SELECT 
    e.employee_id,
    e.first_name,
    e.last_name,
    d.department_name,
    TO_CHAR(e.hire_date, 'YYYY-MM-DD') as hire_date
FROM employees e
LEFT JOIN departments d ON e.department_id = d.department_id
WHERE e.salary > (
    SELECT AVG(salary) 
    FROM employees 
    WHERE department_id = e.department_id
)
ORDER BY e.hire_date DESC;

-- After (PostgreSQL)
SELECT 
    e.employee_id,
    e.first_name,
    e.last_name,
    d.department_name,
    TO_CHAR(e.hire_date, 'YYYY-MM-DD') as hire_date
FROM employees e
LEFT JOIN departments d ON e.department_id = d.department_id
WHERE e.salary > (
    SELECT AVG(salary) 
    FROM employees 
    WHERE department_id = e.department_id
)
ORDER BY e.hire_date DESC;

// Before (Oracle JDBC)
String url = "jdbc:oracle:thin:@localhost:1521:ORCL";
Connection conn = DriverManager.getConnection(url, "user", "pass");

// Oracle-specific SQL
String sql = "SELECT * FROM employees WHERE ROWNUM <= 10";
PreparedStatement stmt = conn.prepareStatement(sql);
ResultSet rs = stmt.executeQuery();

// Date handling
java.util.Date date = new java.util.Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String dateStr = sdf.format(date);

// After (PostgreSQL JDBC)
String url = "jdbc:postgresql://localhost:5432/company";
Connection conn = DriverManager.getConnection(url, "user", "pass");

// PostgreSQL SQL
String sql = "SELECT * FROM employees LIMIT 10";
PreparedStatement stmt = conn.prepareStatement(sql);
ResultSet rs = stmt.executeQuery();

// Modern date handling
LocalDate date = LocalDate.now();
String dateStr = date.format(DateTimeFormatter.ISO_LOCAL_DATE);

# Generate migration tests
autohand test --generate --database oracle --target postgresql

# Validate data integrity
autohand validate --compare-source-target --tolerance 0.001

# Performance testing
autohand benchmark --before oracle --after postgresql

# Generated validation test
def test_employee_data_integrity():
    """Verify employee data migrated correctly"""
    
    # Compare record counts
    oracle_count = execute_oracle("SELECT COUNT(*) FROM employees")
    pg_count = execute_postgres("SELECT COUNT(*) FROM employees")
    assert oracle_count == pg_count
    
    # Compare sample records
    sample_query = "SELECT * FROM employees WHERE employee_id = ?"
    oracle_record = execute_oracle(sample_query, [1001])
    pg_record = execute_postgres(sample_query, [1001])
    
    # Validate data equality
    assert oracle_record['first_name'] == pg_record['first_name']
    assert oracle_record['last_name'] == pg_record['last_name']
    # ... more validations