Constraints enforce data integrity at the database level. PRIMARY KEY ensures uniqueness and identifies rows. FOREIGN KEY maintains referential integrity. NOT NULL prevents null values. UNIQUE prevents duplicates. CHECK validates data conditions. DEFA

Advanced aggregations extract insights from data. ROLLUP creates hierarchical subtotals. CUBE generates all possible grouping combinations. GROUPING SETS specifies exact grouping combinations. FILTER clause conditions aggregations. String aggregation

Materialized views store query results physically for fast access. I use them for expensive aggregations, complex joins, reporting queries. Unlike views, materialized views cache data—need manual refresh. REFRESH MATERIALIZED VIEW updates cached data.

Schema migrations evolve database structure safely. I use migration tools like Flyway, Liquibase, or framework migrations. Version-controlled migrations track schema changes. Up migrations apply changes, down migrations revert. Idempotent migrations c

Connection pooling reuses database connections across requests. Creating connections is expensive—pooling amortizes overhead. I use PgBouncer for PostgreSQL, ProxySQL for MySQL. Session pooling maintains session state. Transaction pooling is more effi

Performance monitoring identifies slow queries and bottlenecks. I use EXPLAIN ANALYZE to profile query execution. pgstatstatements tracks query statistics over time. Slow query logs capture problematic queries. Query execution time, I/O, and buffer us

Backups protect against data loss from failures, corruption, or human error. I use full backups for complete database snapshots. Incremental backups save only changes since last backup. Point-in-time recovery restores to specific moments. Logical back

Database security protects data from unauthorized access. I use GRANT/REVOKE for permissions—SELECT, INSERT, UPDATE, DELETE. Role-based access control groups permissions. Row-level security filters data per user. Column-level security restricts sensit

Full-text search finds documents matching text queries. PostgreSQL tsvector stores processed documents optimized for search. I use tsquery for search queries with operators—AND, OR, NOT. GIN indexes on tsvector columns enable fast search. Text search

Partitioning splits large tables into smaller physical pieces. Range partitioning divides by value ranges—dates, IDs. List partitioning groups by specific values—regions, categories. Hash partitioning distributes evenly across partitions. I use partit

Replication copies data across multiple servers for redundancy and scalability. Master-slave replication has one writable primary, multiple read-only replicas. I use read replicas to scale read-heavy workloads. Master-master allows writes to multiple

Stored procedures encapsulate business logic in database. Functions return values; procedures don't (PostgreSQL 11+). I use functions for reusable calculations, data transformations. PL/pgSQL provides procedural language—variables, loops, conditionals