Explain why, even though SQL is declarative, the query optimizer in a relational DBMS translates SQL statements into relational algebra, which is procedural.

What will be an ideal response?


The relational algebra is procedural and thus provides a concrete algorithm for query evaluation. Algebraic equivalences are then used to ?nd equivalent but more e?cient expressions.

Computer Science & Information Technology

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Capitalization errors usually are caused by accidental use of the ________ key.

A. Shift B. Caps Lock C. Tab D. Num Lock

Computer Science & Information Technology

___________  performance is a term used to describe the number of read and write operations that can be processed by the physical disk in a given time frame.

Fill in the blank(s) with the appropriate word(s).

Computer Science & Information Technology

Which of the following may be used with a BNC connector?

A. 10GBaseT B. 1000BaseSX C. 100BaseFX D. 10Base2

Computer Science & Information Technology

A technician troubleshooting a mail server determines that the server is low on available hard drive space and needs an additional hard drive installed. The server will need to be offline for the hardware installation. Which of the following troubleshooting steps should the technician do NEXT?

A. Notify impacted users of the scheduled maintenance. B. Implement one change at a time. C. Collect additional information. D. Document findings, actions, and outcomes.

Computer Science & Information Technology