Profiler for slow queries in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable the profiler for slow queries in MongoDB.

MongoDB

db.setProfilingLevel([1])

Drag options to blanks, or click blank then click option'

A2

B0

C3

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using level 0 disables profiling.

Level 3 is not a valid profiling level.

Setting profiling level to 1 enables profiling for slow operations only.

2fill in blank

medium

Complete the code to set the slow operation threshold to 100 milliseconds.

MongoDB

db.setProfilingLevel(1, { slowms: [1] })

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A100

B10

C1000

D10000

Attempts:

3 left

💡 Hint

Common Mistakes

Setting slowms too high misses slow queries.

Setting slowms too low may log too many queries.

Setting slowms to 100 means queries slower than 100 milliseconds are profiled.

3fill in blank

hard

Fix the error in the command to retrieve slow queries from the system profiler collection.

MongoDB

db.system.profile.find({ [1]: { $gt: 100 } })

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AexecutionTime

BtimeMillis

Cmillis

DdurationMillis

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect field names like 'durationMillis' or 'timeMillis'.

Using 'executionTime' which is not a valid field.

The field 'millis' stores the query duration in milliseconds in the profiler collection.

4fill in blank

hard

Fill both blanks to query slow operations longer than 200 ms and sort by duration descending.

MongoDB

db.system.profile.find({ [1]: { $gt: 200 } }).sort({ [2]: -1 })

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AdurationMillis

Bmillis

DexecutionTime

Attempts:

3 left

💡 Hint

Common Mistakes

Using different field names for filter and sort.

Sorting ascending instead of descending.

Use 'millis' to filter and sort by query duration in milliseconds.

5fill in blank

hard

Fill all three blanks to enable profiling for slow queries over 150 ms and retrieve them sorted by duration.

MongoDB

db.setProfilingLevel([1], { slowms: [2] }); db.system.profile.find({ [3]: { $gt: 150 } }).sort({ [3]: -1 })

Drag options to blanks, or click blank then click option'

A1

B150

Cmillis

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using profiling level 2 which profiles all queries.

Using inconsistent field names for filtering and sorting.

Profiling level 1 enables slow query profiling with slowms 150 ms. Use 'millis' to filter and sort.