Sql Glossary

Browse 40 sql terms defined in plain English, from the cultural dictionary of computing.

40 Sql Terms

Clause
A distinct component of a SQL statement or logical expression that specifies a condition or operation. In SQL, clauses like WHERE, GROUP BY, and HAVING filter,...
CockroachDB
A distributed SQL database designed for resilience, horizontal scaling, and strong consistency across nodes.
CTE
Common Table Expression — a named temporary result set defined within a SQL statement using the WITH clause. Makes complex queries readable by breaking them...
Database
An organized collection of structured data managed by a database management system (DBMS). Relational databases (PostgreSQL, MySQL) use tables with SQL. NoSQL...
Database Trigger
A database function that executes automatically in response to INSERT, UPDATE, or DELETE events on a table. Can fire BEFORE (to validate/modify) or AFTER (to...
data warehouse
A central repository of structured, cleaned, and organized data optimized for analytical queries and reporting. Unlike operational databases designed for fast...
dbt
Data Build Tool — a transformation framework that lets data analysts write modular SQL to transform raw data into analytics-ready tables. Models are...
Dialect
A variant of a programming language or query language that differs from the standard in syntax or features. SQL dialects (MySQL, PostgreSQL, T-SQL) are the...
Drizzle
A TypeScript ORM that positions itself as 'if you know SQL, you know Drizzle.' Unlike Prisma's abstracted query API, Drizzle provides a SQL-like query builder...
foreign key
A column or set of columns in one table that references the primary key of another table, establishing a link between the two. Foreign keys enforce referential...
index
A data structure (typically a B-tree or hash table) that speeds up data retrieval operations on a database table at the cost of additional storage and slower...
Index Scan vs Seq Scan
Two fundamental data access methods in databases. An index scan uses a B+ tree index to jump directly to matching rows — fast for selective queries. A...
Join
A relational database operation that combines rows from two or more tables based on a related column or join condition. Different join types such as INNER,...
Knex
A SQL query builder for Node.js that provides a fluent, chainable API for constructing database queries across PostgreSQL, MySQL, SQLite, and other engines,...
Lateral Join
A SQL join where the right-hand subquery can reference columns from the left-hand table — like a correlated subquery but returning multiple rows/columns....
Left Join
A SQL join that returns all rows from the left (first) table and the matching rows from the right (second) table, filling in NULLs for right-side columns when...
MariaDB
A community-developed relational database descended from MySQL and used in many web and application stacks.
materialized view
A database object that stores the precomputed results of a query physically on disk, unlike a regular view which re-executes the query each time. Materialized...
MySQL
An open-source relational database management system originally developed by MySQL AB (now Oracle), widely used for web applications and known for its InnoDB...
osquery
An operating-system instrumentation framework that exposes system state through a SQL-like interface for security and operations use cases.
Outer Join
A SQL join that returns all rows from one or both tables even when there is no matching row in the other table, filling in NULLs for the missing side. LEFT...
PostgreSQL
PostgreSQL is an open-source, object-relational database management system known for its standards compliance, extensibility, and reliability. Often referred...
Primary Key
A column or combination of columns in a database table that uniquely identifies each row, enforcing both a uniqueness constraint and a NOT NULL constraint. The...
Procedure
A named sequence of instructions that performs a specific task, called by name from other code. Distinguished from a function in that a procedure traditionally...
Query
A request for data from a database or search engine, typically expressed in a structured language like SQL, GraphQL, or a search DSL. As a verb, to query means...
Query Builder
A programmatic API that lets developers construct database queries using method chaining or composable objects instead of writing raw SQL strings. Query...
Query Engine
The core component of a database or analytics system responsible for parsing, planning, optimizing, and executing queries against stored data. Query engines...
Query Optimizer
The database subsystem that transforms a parsed SQL query into an efficient execution plan by evaluating strategies like join ordering, index selection, and...
Query Plan
The execution strategy chosen by the database's query optimizer for a SQL statement. Shows which indexes are used, join order and method (nested loop, hash,...
query planner
The database component that analyzes a SQL query and determines the most efficient execution strategy — which indexes to use, what join order and algorithms to...
Raw SQL
Hand-written SQL statements executed directly against a database, bypassing an ORM or query builder. Developers drop to raw SQL for complex queries,...
RDBMS
Relational Database Management System — software that stores data in tables of rows and columns, enforces schemas and relational integrity constraints (primary...
Right Join
A SQL join that returns all rows from the right (second) table and the matching rows from the left (first) table, filling in NULLs for left-table columns where...
SQLite
A self-contained, serverless, zero-configuration relational database engine stored as a single file on disk. It is the most widely deployed database in the...
stored procedure
A precompiled program stored in the database that encapsulates SQL statements and procedural logic, executed by calling its name rather than sending raw SQL....
Subquery
A SQL query nested inside another query, typically within a WHERE, FROM, or SELECT clause. The inner query executes first and its result is used by the outer...
Table
A structured collection of data organized in rows and columns within a relational database, where each row represents a record and each column represents a...
trigger
A database object that automatically executes a specified function in response to certain events (INSERT, UPDATE, DELETE) on a table. Triggers enable automatic...
Upsert
An atomic operation that inserts a row if it doesn't exist or updates it if it does, based on a unique key. Eliminates race conditions between separate SELECT...
Window Function
A SQL function that performs a calculation across a set of rows related to the current row, without collapsing them into a single result (unlike GROUP BY)....

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