Original goals of the SQL language What was SQL originally designed to accomplish within relational database systems?
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ASpecify the syntax and semantics of the SQL data definition language (DDL).
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BSpecify the syntax and semantics of the SQL data manipulation language (DML).
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CDefine and manage relational data structures and constraints.
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DAll of the above.
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EGenerate operating-system file handles for tables.
Answer
Correct Answer: All of the above.
Explanation
Introduction / Context:SQL emerged from the relational model to provide a declarative, vendor-neutral way to define schemas and manipulate data. Its scope covers both structure and data, enabling a complete lifecycle from creation to query to update using a single language.
Given Data / Assumptions:
- Relational databases require a language for structure (DDL) and data (DML).
- Standards bodies formalized SQL so multiple vendors could implement it.
- Constraints and relationships are part of the structural definition.
Concept / Approach:
SQL's charter includes DDL (CREATE/ALTER/DROP) to define tables, keys, and constraints; DML (SELECT/INSERT/UPDATE/DELETE) to read and modify data; and related control statements for permissions and transactions. Therefore, its original purpose encompasses all items listed except operating-system concerns.
Step-by-Step Solution:
Map DDL responsibilities to structure definition and constraints.Map DML responsibilities to data retrieval and modification.Confirm that SQL was intended to unify these under one standard.Select the comprehensive choice: All of the above.Verification / Alternative check:
Historical papers on System R and standards documentation confirm SQL's dual role in structure and manipulation, later expanded by security and transaction controls.
Why Other Options Are Wrong:
- A/B/C alone are too narrow; SQL was not limited to a single facet.
- E: Outside SQL's scope; OS file handles are managed by the DBMS internals, not SQL.
Common Pitfalls:
- Equating SQL only with querying, ignoring DDL and constraints that enforce data quality.
Final Answer:
All of the above.