developer-roadmap/content/roadmaps/7-postgresql-dba/0-About/0-Summary.md

PostgreSQL DBA Roadmap

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
• 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
• Official Docker images

Learn SQL concepts

Get practical skills of how to create and manipulate database objects and how to execute queries using psql client.

• Understanding 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
• PostgreSQL Tutorial
• PostgreSQL SQL Getting Started
• The SQL Language

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 autovacuum
• replication
• query planner
• reporting, logging and statistics
• adding extra extensions
• ... keep exploring other configuration options Links:
• 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
• Roles and users managements

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
• System catalog
• Fine-grained tuning:
• Per-user, per-database settings
• 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 for database administrators and system developers
• PL/pgSQL Guide

Learn Postgres troubleshooting technics

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
• Depesz online EXPLAIN visualization tool
• PEV online EXPLAIN visualization tool
• Tensor 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 by Brendan Gregg
• USE Method

Learn SQL optimization technics

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 - 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
  • pgsql-general
  • pgsql-admin
  • pgsql-performance
  • pgsql-hackers
  • pgsql-bugs
• reviewing patches
• writing patches, attending in Commitfests