Question

Database in records in managed in which data structure

Answer 1

Query evaluation is performed in several steps as outlined in Figure 60.2. Starting with the

high-level input query expressed in a declarative language called SQL (see, for example, [2])

the Parser scans, parses, and validates the query. The goal is to check whether the query

is formulated according to the syntax rules of the language supported in the DBMS. The

parser also validates that all attribute and relation names are part of the database schema

that is being queried.