The intent of this guide is to give you an idea about the DBA landscape and to help guide your learning if you are confused. The roadmap is highly opinionated — neither, knowing everything listed in the roadmap, nor the order of items given in the roadmap is required to be followed in order to be a DBA.
## Learn basic RDBMS terms and concepts
Get basic understanding of Postgres key terms and basic RDBMS concepts.
- **Object model**: data types, columns, rows, tables, schemas, databases, queries.
- **Relational model**: domains, attributes, tuples, relations, constraints, NULL.
- **Databases high-level concepts**: ACID, MVCC, transactions, write-ahead log, query processing.
- **Links**:
- [Postgres Glossary](https://www.postgresql.org/docs/13/glossary.html)
- SQL and Relational Theory - Christopher J. Date, 2009
- Database Design and Relational Theory - Christopher J. Date, 2012
## Learn how to install and run PostgreSQL
Get practical skills of how to set up and run Postgres to get a working environment for further learning.
- Using package managers (APT, YUM, etc.)
- Using `docker`.
- Managing Postgres service using `systemd` (start, stop, restart, reload).
- Managing Postgres service using `pg_ctl`, or OS-specific tools (like `pg_ctlcluster`).
- Connect to Postgres using `psql`.
- Deploy database service in cloud environment (AWS, GCE, Azure, Heroku, DigitalOcean, etc...).
- **Links**:
- [Official download and install instructions](https://www.postgresql.org/download/)
- [Official Docker images](https://hub.docker.com/_/postgres)
## Learn SQL concepts
Get practical skills of how to create and manipulate database objects and how to execute queries using `psql` client.
- Understand basic data types.
- **DML queries**: querying data, modifying data, filtering data, joining tables.
- **Advanced topics**: transactions, CTE, subqueries, lateral join, grouping, set operations.
- **DDL queries**: managing tables and schemas (create, alter, drop).
- Import and export data using `COPY`.
- **Links**:
- [DB Fiddle](https://www.db-fiddle.com/)
- [PostgreSQL Tutorial](https://www.postgresqltutorial.com/)
- [PostgreSQL SQL Getting Started](https://www.postgresql.org/docs/current/tutorial-sql.html)
- [The SQL Language](https://www.postgresql.org/docs/current/sql.html)
## Learn how to configure Postgres
Get understanding of the main aspects of how Postgres could be configured. Deep understanding of Postgres internals is not yet necessary here.
- postgresql.conf:
- Resources usage
- Write-ahead Log
- Checkpoints and Background Writer
- Cost-based vacuum and auto-vacuum
- Replication
- Query planner
- Reporting, logging and statistics
- Adding extra extensions
- ...keep exploring other configuration options
- **Links**:
- [Postgresqlco.nf](http://postgresqlco.nf/)
## Learn Postgres security concepts
Get understanding about basic security concepts and common ways of how to deploy secure configurations.
- Authentication models, roles, pg_hba.conf, SSL settings.
- **Objects privileges**: grant/revoke, default privileges.
- **Advanced topics** - row-level security, selinux.
- **Links**:
- [Client authentication](https://www.postgresql.org/docs/current/client-authentication.html)
- [Roles and users managements](https://www.postgresql.org/docs/current/user-manag.html)
## Develop infrastructure DBA skills
Get practical skills of how to deploy, extend, maintain and support Postgres installations and 3rd-party Postgres ecosystem software.
- **Replication**: streaming replication, logical replication
- **Backup/recovery tools**:
- Built-in: `pg_dump`, `pg_dumpall`, `pg_restore`, `pg_basebackup`
- 3rd-party: `barman`, `pgbackrest`, `pg_probackup`, `WAL-G`
- Backup validation procedures
- **Upgrading procedures**
- Minor and major upgrades using `pg_upgrade`
- Upgrades using logical replication
- **Connection pooling**:
- `Pgbouncer`
- Alternatives: `Pgpool-II`, `Odyssey`, `Pgagroal`
- **Infrastructure monitoring**: `Prometheus`, `Zabbix`, other favourite monitoring solution
- **High availability and cluster management tools**:
- `Patroni`
- **Alternatives**: `Repmgr`, `Stolon`, `pg_auto_failover`, `PAF`
- **Applications Load Balancing and Service Discovery**: `Haproxy`, `Keepalived`, `Consul`, `Etcd`
- **Deploy Postgres on `Kubernetes`**: Simple `StatefulSet` setup, `HELM`, operators
- Resource usage and provisioning, capacity planning
## Learn how to automate routines
Get practical skills, learn automation tools and automate existing routine tasks.
- Automation using shell scripts or any other favourite language (`Bash`, `Python`, `Perl`, etc)
- Configuration management: `Ansible`, `Salt`, `Chef`, `Puppet`
## Develop application DBA skills
Learn theory and get practical skills of how applications should work with Postgres
- **Migrations**:
- practical patterns and antipatterns
- tools: `liquibase`, `sqitch`, language-specific tools
- Data import/export, bulk loading and processing
- **Queues**:
- practical patterns and anti-patterns
- `Skytools PGQ`
- Data partitioning and sharding patterns.
- Database normalization and normal forms.
- Books:
- The Art of PostgreSQL - Dimitri Fontaine, 2020
## Learn Postgres advanced topics
Here is important to continuously extend and develop existing knowledge about Postgres.
- **Low level internals**:
- Processes and memory architecture
- Vacuum processing
- Buffer management
- Lock management
- [Physical storage and file layout](https://www.postgresql.org/docs/current/storage.html)
- [System catalog](https://www.postgresql.org/docs/current/catalogs.html)
- **Fine-grained tuning**:
- Per-user, per-database settings
- [Storage parameters](https://www.postgresql.org/docs/current/sql-createtable.html#SQL-CREATETABLE-STORAGE-PARAMETERS)
- Workload-dependant tuning: OLTP, OLAP, HTAP
- **Advanced SQL topics**:
- PL/pgSQL, procedures and functions, triggers
- Aggregate and window functions
- Recursive CTE
- **Links**:
- [The Internals of PostgreSQL](http://www.interdb.jp/pg/index.html) for database administrators and system developers
- [PL/pgSQL Guide](https://www.postgresql.org/docs/current/plpgsql.html)
## Learn Postgres troubleshooting techniques
Get basic understanding about troubleshooting tools and get practical skills of how to detect and resolve problems.
- **Operating system tools**
- `top` (`htop`, `atop`)
- `sysstat`
- `iotop`
- **Postgres system views**
- `pg_stat_activity`
- `pg_stat_statements`
- **Postgres tools**
- `pgcenter` - *personal recommendation*
- **Query analyzing**:
- [EXPLAIN](https://www.postgresql.org/docs/current/sql-explain.html)
- [Depesz](https://explain.depesz.com/) online EXPLAIN visualization tool
- [PEV](https://tatiyants.com/pev/#/plans) online EXPLAIN visualization tool
- [Tensor](https://explain.tensor.ru/) online EXPLAIN visualization tool, RU language only
- **Log analyzing**:
- `pgBadger`
- Ad-hoc analyzing using `grep`, `awk`, `sed`, etc.
- **External tracing/profiling tools**: `gdb`, `strace`, `perf-tools`, `ebpf`, core dumps
- **Troubleshooting methods**: USE, RED, Golden signals
- **Links**:
- [Linux Performance](http://www.brendangregg.com/linuxperf.html) by Brendan Gregg
- [USE Method](http://www.brendangregg.com/usemethod.html)
## Learn SQL optimization techniques
Get understanding and practical skills of how to optimize SQL queries.
- **Indexes, and their use cases**: B-tree, Hash, GiST, SP-GiST, GIN, BRIN
- SQL queries patterns and anti-patterns
- SQL schema design patterns and anti-patterns
- **Links**:
- [Use the Index, Luke](https://use-the-index-luke.com/) - a Guide to Database Performance for Developers
- **Books**:
- SQL Antipatterns: Avoiding the Pitfalls of Database Programming - Bill Karwin, 2010
## Develop architect skills
Get deeper understanding of Postgres use cases and where Postgres is suitable and where is not.
- **Postgres forks and extensions**: `Greenplum`, `Timescaledb`, `Citus`, `Postgres-XL`, etc.
- RDBMS in general, benefits and limitations
- Differences between Postgres and other RDBMS and NoSQL databases
## Develop Postgres hacker skills
Get involved to Postgres community and contribute to Postgres; be a useful member of Postgres, and the open source community; use personal experience to help other people.
- Daily reading and answering in [mailing lists](https://www.postgresql.org/list/)
- pgsql-general
- pgsql-admin
- pgsql-performance
- pgsql-hackers
- pgsql-bugs
- Reviewing patches
- Writing patches, attending in [Commitfests](https://commitfest.postgresql.org/)