PostgreSQL
Learn PostgreSQL end to end. SQL basics, joins, indexes, transactions, JSONB, EXPLAIN, and schema design.
14 lessons, in order
- 120 min
What is PostgreSQL
Relational databaseACIDMVCCPostgres vs MySQL vs SQLiteWhere Postgres shines - 225 min
psql and First Commands
Psql command line clientConnecting as postgres userMeta commands like \l \c \dt \d \qSemicolons end statementsMultiline queriesSELECT version() - 330 min
Creating Databases and Tables
CREATE DATABASECREATE TABLEPRIMARY KEYNOT NULLDEFAULTDROP TABLE+1 - 425 min
Data Types
Integer and bigintNumeric vs floatText and varcharBooleanTimestamptz vs timestampDate+3 - 530 min
SELECT and WHERE
SELECT specific columnsWHERE with AND ORBETWEENINLIKE and ILIKEIS NULL+2 - 635 min
Joins
INNER JOINLEFT JOINRIGHT JOINFULL OUTER JOINSelf joinUSING vs ON - 730 min
Aggregates and Grouping
COUNTSUMAVGMINMAXGROUP BY+3 - 835 min
Indexes
B-tree defaultCREATE INDEXMulti-column indexPartial index WHERE activeUnique indexWrite cost+1 - 935 min
Transactions and Isolation
BEGIN COMMIT ROLLBACKSavepointsREAD COMMITTED defaultREPEATABLE READSERIALIZABLEDirty read non-repeatable read phantom read serialization anomaly - 1035 min
Functions and Triggers
CREATE FUNCTIONLANGUAGE plpgsqlRETURNSCREATE TRIGGERBEFORE UPDATENEW and OLD+1 - 1135 min
JSONB and Arrays
JSONB column-> operator->> operator@> contains operatorGIN index on jsonbText[] and integer[] arrays+2 - 1235 min
EXPLAIN and Query Tuning
EXPLAINEXPLAIN ANALYZESeq scan vs index scan vs index-only scanFixing a missing indexPg_stat_statements overview - 1325 min
Backup and Restore
Pg_dump custom formatPg_restorePlain SQL dumpsPoint-in-time recovery overview - 1460 min
Capstone: Design a Schema
Schema designPrimary and foreign keysIndexes on hot columnsUpdated_at triggerJSONB metadataJoins with aggregates+1
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Roles that use PostgreSQL
See how hiring teams interview engineers on PostgreSQL, in production-like environments.
Database Administrator (DBA)
Hire DBAs in real workspaces with PostgreSQL or MySQL, real replication lag, real slow queries and real backups to restore. Live or take-home.
See the interviewBackend Engineer (Go, Rust, Java)
Hire backend engineers in real services with real databases, real concurrency and real latency budgets. Live or take-home, fully recorded.
See the interviewData Engineer
Hire data engineers in workspaces with real Spark, dbt and Airflow pipelines. Schema drift, bad data and reruns included.
See the interview