PostgreSQL Database Administrator

**L1 PostgreSQL Database Administrator**

Job Summary:
The L1 PostgreSQL Database Administrator is responsible for routine database operations, including monitoring, maintenance, and basic troubleshooting. This role is crucial in ensuring the continuous availability and performance of PostgreSQL databases, handling day-to-day tasks with guidance from higher-level DBAs.

**Technical Responsibilities**:
**Database Monitoring & Alerting**:
Utilize monitoring tools like pgAdmin, Prometheus with Grafana, or Nagios to track key PostgreSQL metrics (e.g., query execution times, CPU/IO load, replication status).

Set up and manage alerting systems to notify about thresholds breaches (e.g., disk space, connection limits).

**Backup and Recovery Management**:
Execute regular backups using tools like pg_dump, pg_basebackup, and configure automated backup scripts.

Perform data restoration using pg_restore and validate backup integrity using checksums and test restores.

**User Management and Security**:
Manage PostgreSQL roles and privileges using SQL commands (CREATE ROLE, GRANT, REVOKE).

Enforce basic security protocols, including SSL configuration and enforcing password policies.

**Basic Performance Tuning**:
Perform routine maintenance tasks like VACUUM, VACUUM FULL, ANALYZE, and REINDEX to optimize table performance.

Identify and create indexes based on slow query logs (pg_stat_statements).

**Database Maintenance & Housekeeping**:
Monitor and maintain logs using pgBadger for performance insights and log rotation.

Implement periodic pg_repack or cluster operations to reorganize tables and indexes.

**Patching and Updates**:
Validate patches in a staging environment before production deployment.

**Basic Troubleshooting**:
Diagnose and resolve common issues like connection timeouts, lock contention, and missing indexes.

Use PostgreSQL diagnostic views (pg_stat_activity, pg_locks) for issue identification.

**Documentation and Reporting**:
Document standard operating procedures (SOPs), database configurations, and maintenance scripts.

Maintain an incident log for database issues and resolutions.

**Technical Skills**:
Operating Systems: Proficient in Linux/Unix (e.g., CentOS, Ubuntu), with basic shell scripting.

PostgreSQL Tools: psql, pgAdmin, pg_dump, pg_restore, pg_basebackup.

SQL: Basic to intermediate SQL scripting, query tuning, and optimization.

Monitoring Tools: Prometheus, Grafana, Nagios, pg_stat_statements.

Scripting: Basic Bash/Python for automation of routine tasks.
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- **Job Title**:
**L2 PostgreSQL Database Administrator**

Job Summary:
The L2 PostgreSQL Database Administrator handles advanced database tasks, including performance tuning, replication, and disaster recovery planning. This role involves in-depth troubleshooting and optimizing database systems to ensure efficient operations and high availability.

**Technical Responsibilities**:
**Advanced Performance Tuning**:
Perform in-depth query optimization using EXPLAIN, EXPLAIN ANALYZE, auto_explain, and pg_stat_statements.

Optimize PostgreSQL configuration parameters (shared_buffers, work_mem, maintenance_work_mem, effective_cache_size) for performance improvements.

Implement partitioning strategies and fine-tune indexing (including BRIN, GIN, and GiST indexes).

**Replication & High Availability**:
Set up and manage replication configurations (e.g., streaming replication, logical replication).

Implement and monitor high-availability solutions using tools like Patroni, pg_auto_failover, or PgBouncer for connection pooling.

**Backup & Disaster Recovery**:
Design and implement comprehensive backup strategies using pgBackRest, Barman, or custom scripts.

Develop and regularly test disaster recovery plans, including Point-In-Time Recovery (PITR) scenarios.

**Security Hardening**:
Enforce advanced security measures, including database encryption (e.g., TLS, data-at-rest encryption), role-based access control (RBAC), and auditing with tools like pgAudit.

Conduct regular security audits and vulnerability assessments.

**Data Migration & Upgrades**:
Plan and execute major version upgrades using techniques like pg_upgrade, and handle data migrations with mínimal downtime.

Perform cross-platform migrations (e.g., from Oracle to PostgreSQL) using tools like Ora2Pg.

**Troubleshooting & Root Cause Analysis**:
Perform deep-dive troubleshooting of complex issues (e.g., deadlocks, replication lag, high latency queries) using PostgreSQL logs, pg_stat_activity, pg_locks, pg_stat_user_tables.

Lead incident response and root cause analysis for critical production issues.

**Automation & Scripting**:
Develop automation scripts for routine database tasks (e.g., backups, monitoring) using Bash, Python, or Ansible.

Implement Infrastructure as Code (IaC) for PostgreSQL environments using tools like Terraform.

**Documentation & Mentori