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/)