Alibaba Exam ACA-Operator Topic 9 Question 74 Discussion

Actual exam question for Alibaba's ACA-Operator exam

Question #: 74
Topic #: 9

When you use SQL statements to access tables in a database without an index configured, a full table scan will be performed. If a table contains a large amount of data, this kind of scan will access a large amount of data and consume a lot of the database's resources. Which of the following options are best practices when creating database indexes? (Number of correct answers: 3)

AAdd an index to a field that is frequently queried but does not frequently perform add, delete, or modify operations.

BApplies indices to fields to contain many records.

CA table should not contaiiAiore than 6 indexed fields.

DApply indexing to fields of fixed length (preferably not long fields).

EAdhere to the rightmost prefix principle when using composite indexes

Show Suggested Answer

Suggested Answer: A, C, D

by Larue at Oct 23, 2024, 09:48 PM

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Emily

6 days ago

Haha, C is just silly. A table shouldn't have more than 6 indexed fields? Who came up with that rule? I'm going with A, D, and E as the best options.

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Diane

8 days ago

I believe option E is also important. Adhering to the rightmost prefix principle can optimize composite indexes.

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Stefan

9 days ago

I agree with you, Kimi. Adding an index to a frequently queried field can improve performance.

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Gabriele

12 days ago

B is definitely not a good practice. Indexing fields with many records can actually slow down performance. I'm going with A, D, and E as the correct answers.

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Kirby

13 days ago

I think A, D, and E are the best options here. Indexing frequently queried fields is a no-brainer, and fixed-length fields are easier to index efficiently. The rightmost prefix principle is also important for composite indexes.

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Kimi

19 days ago

I think option A is a good practice for creating database indexes.

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