orapredicate

Orapredicate is an informal term encountered in some discussions to denote the boolean expression in Oracle SQL that filters rows. It is not an official Oracle product or feature name, but it appears in user guides and blogs as shorthand for the predicate component of a SQL statement. In practice, orapredicate refers to any condition that determines whether a row satisfies a query.

In Oracle, predicates appear in the where clause, having clause, join conditions (on), or in subqueries. They include simple predicates like age > 18, range predicates like salary BETWEEN 50000 AND 100000, set predicates like department_id IN (10, 20, 30), and null checks like name IS NULL. They can be combined with logical operators AND, OR, and NOT to form compound predicates.

Predicates influence execution plans. The optimizer uses predicate selectivity estimates to choose access paths (index scans, full table scans) and the join order. Predicate pushdown may move certain predicates closer to data retrieval to prune rows early. The database engine also applies predicates during execution, sometimes evaluating them in a different order than written, subject to short-circuit semantics.

Terminology note: "orapredicate" is not a formal Oracle term; references vary and often use "predicate" or "conjunct" instead. For precise behavior, consult Oracle’s documentation on predicates, the cost-based optimizer, and execution plans. In practice, tuning focuses on how predicates interact with indexes and how they affect selectivity and performance.