Oracle Exam 1Z0-908 Topic 5 Question 75 Discussion

Actual exam question for Oracle's 1Z0-908 exam

Question #: 75
Topic #: 5

Which statement is true about InnoDB persistent index statistics?

AUpdating index statistics is an I/O expensive operation.

BIndex statistics are calculated from pages buffered in the buffer pool for tables with InnoDB storage engine.

CSetting innodb_stats_auto_recalc=ON causes statistics to be updated automatically when a new index is created.

DExecution plans based on transient index statistics improve precision when innodb_stats_persistent_sample_pages is increased.

EIncreasing innodb_stats_persistent_sample_pages determines higher pages scanning speed, at the cost of increased memory usage.

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Suggested Answer: A

by Carmelina at Apr 09, 2024, 07:05 PM

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Sylvie

6 months ago

I personally think E) Increasing innodb_stats_persistent_sample_pages for higher scanning speed, at the cost of more memory usage, is a trade-off worth considering. Efficiency is key.

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Weldon

6 months ago

I'm leaning towards D) Execution plans based on transient index statistics improve precision when innodb_stats_persistent_sample_pages is increased. It makes sense for better accuracy.

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Elvera

7 months ago

I agree with Alice on B), but I think C) Setting innodb_stats_auto_recalc=ON causing automatic updates is an important feature for keeping statistics updated.

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Goldie

7 months ago

I believe A) Updating index statistics is an I/O expensive operation is also true. It can be costly in terms of performance.

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Lauran

7 months ago

I think the correct answer is B) Index statistics are calculated from pages buffered in the buffer pool for tables with InnoDB storage engine.

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Sheridan

8 months ago

Option E seems a bit counterintuitive. Increasing sampling should improve speed, but higher memory usage? That's a tradeoff I'd need to understand better.

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Eve

8 months ago

Option D is interesting, but I'm not sure how transient statistics would improve precision. Wouldn't persistent statistics be more reliable?

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Letha

8 months ago

Option C sounds plausible. If we have auto-recalc enabled, the statistics should update automatically when a new index is created.

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Anglea

8 months ago

I'm not sure about option B. Wouldn't the index statistics be calculated from the actual data, not just the pages in the buffer pool?

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Eliseo

8 months ago

Hmm, I think option A might be correct. Updating index statistics probably involves a lot of I/O, which can be expensive.

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Lenny

7 months ago

But index statistics are calculated from pages buffered in the buffer pool for tables with InnoDB storage engine.

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Helene

7 months ago

I agree, updating index statistics is indeed an I/O expensive operation.

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Romana

8 months ago

This question seems a bit tricky. I'm not sure if I fully understand the difference between persistent and transient index statistics.

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