pingcap/tidb

Use a new struct to store the props generated by `preparePossibleProperties`

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#10,749 opened on Jun 10, 2019

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help wantedsig/plannertype/performance

Description

after https://github.com/pingcap/tidb/pull/10548 There'll be multiple props which share the same suffix. We can implement a struct which can store the eqPrefixLen to cut off the possible props then reduce the search space.

Contributor guide

Tech stack
go
Domain
databaseperformance
Issue type
refactor
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Go programmingTiDB internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
Review the referenced PR #10548 to understand the background about multiple props sharing suffixes. Look at the current implementation of `preparePossibleProperties` in the TiDB source code to identify where the new struct should be introduced. The goal is to encapsulate `eqPrefixLen` and the props in a struct to reduce search space. There are no comments or additional guidance, so the contributor may need to propose a design in the issue first.
Use a new struct to store the props generated by `preparePossibleProperties` · pingcap/tidb#10749 | Good First Issue