Details
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New Feature
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Resolution: Duplicate
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Major - P3
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None
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None
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Query
Description
If an application scans by index, then serverStatus().indexCounters.btree.accesses shows the counts and activity against the index. However, if your application is performing scans not using an index (perhaps sub-optimally) there is no metric that shows anything. If a metric was exposed then it would be possible to spot poor plans/scans as well as do ratios of scans vs index accesses. Just a typical pattern for DBA's to see what the DB is doing at any given time. Perhaps the metric could be named: serverStatus().collections.scans. This is also good for an application where scans are needed (like the reads are most of the table) to show the DB activity during these periods. It's also a good measure of overall workload of the DB (scans/sec) and helps to differentiate different I/O patterns/performance. For instance how it changes when faults > 0, and also how it changes platform to platform (aka: I can scan more blocks with platform X).
Attachments
Issue Links
- duplicates
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SERVER-40755 Expose statistics which indicate how many collection scans have executed
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- Closed
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