[SERVER-70659] Cardinality estimate of the minimum values of data types Created: 18/Oct/22  Updated: 29/Oct/23  Resolved: 10/Nov/22

Status: Closed
Project: Core Server
Component/s: None
Affects Version/s: None
Fix Version/s: 6.2.0-rc0

Type: Improvement Priority: Major - P3
Reporter: Milena Ivanova Assignee: Milena Ivanova
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Backwards Compatibility: Fully Compatible
Sprint: QO 2022-11-14
Participants:

 Description   

Investigate what is the best cardinality estimate of the minimum value of a given data type, e.g. empty string. When the value falls inside of a bucket we can estimate the equality as follows:

1) use the equality frequency for the inner bucket values (rangeFreq / NDV)

2) use kMinCard = 0.01 (if the value actually exists in the data, this will lead to underestimation).



 Comments   
Comment by Githook User [ 10/Nov/22 ]

Author:

{'name': 'Milena Ivanova', 'email': 'milena.ivanova@mongodb.com', 'username': 'mivanova3'}

Message: SERVER-70659 Cardinality estimate of the minimum values of data types
Branch: master
https://github.com/mongodb/mongo/commit/d5ff440817391833df0ee8d918689cef60140d90

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