[SERVER-68968] Optimize column scan filter pushdown Created: 18/Aug/22  Updated: 29/Oct/23  Resolved: 11/Sep/22

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

Type: Task Priority: Major - P3
Reporter: Ian Boros Assignee: Mohammad Dashti (Inactive)
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Depends
is depended on by SERVER-69105 Achieve column index performance acce... Closed
Backwards Compatibility: Fully Compatible
Sprint: QE 2022-09-19
Participants:

 Description   

Based on what we've found in profiling, there are a few really simple optimizations for per-column filters that we should do.

Here's a simple query on the bestbuy dataset which exercises the behavior. The filter does not match anything.

db.products.aggregate([{$match:{'type': 'asdf'}}, {$group:{_id:'$type', count: {$sum:1}}}])

We should change this to not copy values out of the column index in order to apply the filter to them. This means putting an unowned value into the slot used for filtering here.

These are only ideas for a starting point. We can also split these into separate tickets.



 Comments   
Comment by Githook User [ 11/Sep/22 ]

Author:

{'name': 'Mohammad Dashti', 'email': 'mdashti@gmail.com', 'username': 'mdashti'}

Message: SERVER-68968 Avioded unnecessary copying slot values
Branch: master
https://github.com/mongodb/mongo/commit/3cad68e7f4f687dc2f199622025998b7a4e4eff3

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