# Database glossary: Journeyman level

57 Database terms at the Journeyman level, each with a short definition and a link to its full page.

Updated: September 28, 2026

[Study these as flash cards](https://www.ask-codey.com/decks/database/journeyman)

- [ACID Compliance](https://www.ask-codey.com/glossary/acid-compliance): Atomic, Consistent, Isolated, Durable
- [ACID Properties](https://www.ask-codey.com/glossary/acid-properties): Atomicity, consistency, isolation, and durability: four goals for reliable transactions.
- [Alternate Key](https://www.ask-codey.com/glossary/alternate-key): A candidate key not selected as the primary key.
- [Associative Entity](https://www.ask-codey.com/glossary/associative-entity): An entity representing a relationship and optionally storing attributes about that relationship.
- [Atomicity](https://www.ask-codey.com/glossary/atomicity): The property that all work in a transaction succeeds together or none of it takes effect.
- [Boyce-Codd Normal Form (BCNF)](https://www.ask-codey.com/glossary/boyce-codd-normal-form-bcnf): A normal form requiring every determinant of a nontrivial dependency to be a superkey.
- [Candidate Key](https://www.ask-codey.com/glossary/candidate-key): A minimal set of attributes that uniquely identifies every tuple in a relation.
- [Clustered Index](https://www.ask-codey.com/glossary/clustered-index): The index that decides the order rows are stored in; one per table.
- [COMMIT](https://www.ask-codey.com/glossary/commit): A statement that successfully ends a transaction and makes its changes durable.
- [Common Table Expression (CTE)](https://www.ask-codey.com/glossary/common-table-expression-cte): A named query expression introduced by WITH for use within one statement.
- [Composite Key](https://www.ask-codey.com/glossary/composite-key): A key made from two or more attributes.
- [Consistency](https://www.ask-codey.com/glossary/consistency): The property that a successful transaction preserves declared database rules.
- [Correlated Subquery](https://www.ask-codey.com/glossary/correlated-subquery): A subquery that refers to values from an outer query and is evaluated in that context.
- [Delete Anomaly](https://www.ask-codey.com/glossary/delete-anomaly): A design problem where deleting one fact unintentionally removes another fact.
- [Denormalization](https://www.ask-codey.com/glossary/denormalization): Deliberately adding controlled redundancy to support a measured performance or reporting need.
- [DENSE_RANK](https://www.ask-codey.com/glossary/dense-rank): A window function assigning equal rank to peers without leaving gaps after ties.
- [Determinant](https://www.ask-codey.com/glossary/determinant): The attribute set on the left side of a functional dependency.
- [Durability](https://www.ask-codey.com/glossary/durability): The property that committed changes survive a later failure.
- [Entity Integrity](https://www.ask-codey.com/glossary/entity-integrity): The rule that every relation has a primary key whose values are unique and non-NULL.
- [First Normal Form (1NF)](https://www.ask-codey.com/glossary/first-normal-form-1nf): The normal form requiring each attribute value to be a single value from its domain.
- [Functional Dependency](https://www.ask-codey.com/glossary/functional-dependency): A rule where one set of attributes determines another set of attributes.
- [Index](https://www.ask-codey.com/glossary/index): An auxiliary data structure that helps an RDBMS locate rows without scanning every row.
- [Insert Anomaly](https://www.ask-codey.com/glossary/insert-anomaly): A design problem where one fact cannot be stored without supplying an unrelated fact.
- [Isolation](https://www.ask-codey.com/glossary/isolation): The property controlling how concurrent transactions can observe one another's work.
- [Junction Table](https://www.ask-codey.com/glossary/junction-table): A table that represents a many-to-many relationship through foreign keys.
- [LAG](https://www.ask-codey.com/glossary/lag): A window function returning a value from an earlier row in the window partition.
- [LEAD](https://www.ask-codey.com/glossary/lead): A window function returning a value from a later row in the window partition.
- [Natural Key](https://www.ask-codey.com/glossary/natural-key): A key formed from meaningful values that already belong to the modeled domain.
- [Nonclustered Index](https://www.ask-codey.com/glossary/nonclustered-index): A separate sorted lookup structure that points back to the rows.
- [Normalization](https://www.ask-codey.com/glossary/normalization): Organizing relations to reduce redundancy and prevent modification anomalies.
- [OVER Clause](https://www.ask-codey.com/glossary/over-clause): The clause defining the row window used by a window function.
- [Parameterized Query](https://www.ask-codey.com/glossary/parameterized-query): A query keeping data values separate from SQL text through parameters.
- [PARTITION BY](https://www.ask-codey.com/glossary/partition-by): An OVER subclause dividing query rows into independent window-function groups.
- [Prepared Statement](https://www.ask-codey.com/glossary/prepared-statement): A parsed statement template executed later with supplied parameter values.
- [RANK](https://www.ask-codey.com/glossary/rank): A window function assigning equal rank to peers and leaving gaps after ties.
- [READ COMMITTED](https://www.ask-codey.com/glossary/read-committed): An isolation level preventing a statement from reading uncommitted changes.
- [READ UNCOMMITTED](https://www.ask-codey.com/glossary/read-uncommitted): The isolation level allowing the broadest concurrency and permitting dirty reads.
- [Recursive CTE](https://www.ask-codey.com/glossary/recursive-cte): A CTE that repeatedly refers to its own accumulated result until no new rows are produced.
- [Referential Integrity](https://www.ask-codey.com/glossary/referential-integrity): The rule that foreign-key values must reference an existing allowed key or be NULL when permitted.
- [REPEATABLE READ](https://www.ask-codey.com/glossary/repeatable-read): An isolation level preventing reread rows from changing during the transaction.
- [ROLLBACK](https://www.ask-codey.com/glossary/rollback): A statement that reverses a transaction's uncommitted changes.
- [ROW_NUMBER](https://www.ask-codey.com/glossary/row-number): A window function assigning consecutive numbers to rows within each window partition.
- [SAVEPOINT](https://www.ask-codey.com/glossary/savepoint): A named point inside a transaction to which later work can be rolled back.
- [Second Normal Form (2NF)](https://www.ask-codey.com/glossary/second-normal-form-2nf): First normal form with no non-key attribute dependent on only part of a candidate key.
- [SERIALIZABLE](https://www.ask-codey.com/glossary/serializable): The strongest standard isolation level, requiring results consistent with some serial order.
- [SQL Injection](https://www.ask-codey.com/glossary/sql-injection): A vulnerability where untrusted input changes the intended structure of a SQL statement.
- [Stored Procedure](https://www.ask-codey.com/glossary/stored-procedure): A named, saved set of SQL statements with parameters.
- [Superkey](https://www.ask-codey.com/glossary/superkey): Any attribute set that uniquely identifies every tuple, including sets with unnecessary attributes.
- [Surrogate Key](https://www.ask-codey.com/glossary/surrogate-key): A key introduced solely to identify rows and carrying no domain meaning.
- [Third Normal Form (3NF)](https://www.ask-codey.com/glossary/third-normal-form-3nf): Second normal form with non-key attributes depending on keys rather than other non-key attributes.
- [Transaction](https://www.ask-codey.com/glossary/transaction): A logical unit of database work completed or reversed as a whole.
- [Transaction Isolation Level](https://www.ask-codey.com/glossary/transaction-isolation-level): A setting defining which effects of concurrent transactions may be observed.
- [Trigger](https://www.ask-codey.com/glossary/trigger): Code that runs automatically when a table's rows change.
- [Unique Index](https://www.ask-codey.com/glossary/unique-index): An index that also prevents duplicate indexed value combinations.
- [Update Anomaly](https://www.ask-codey.com/glossary/update-anomaly): A design problem where repeated copies of one fact can become inconsistent during an update.
- [Window Frame](https://www.ask-codey.com/glossary/window-frame): The subset of rows around the current row used by a window function.
- [Window Function](https://www.ask-codey.com/glossary/window-function): A function calculating across related rows without collapsing them into one row per group.

- Previous level: [Apprentice](https://www.ask-codey.com/glossary/subjects/database/apprentice)
- Next level: [Freelancer](https://www.ask-codey.com/glossary/subjects/database/freelancer)

[Every Database term, by level](https://www.ask-codey.com/glossary/subjects/database)

Source: https://www.ask-codey.com/glossary/subjects/database/journeyman