pingcap/tidb

use hack.Slice in ColumnInfo:Dump to avoid unnecessary `string to slice` conversation

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#32,073 opened on Jan 30, 2022

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help wantedtype/enhancementtype/performance

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Description

Enhancement

In some read-heavy workloads, we found that Column Dump causes some CPUs

image

Through the flamegraph, we can see that nearly 1% of CPU is caused by string to slice conversation. We can ensure that we don't change the slice value in the Dump function, https://github.com/pingcap/tidb/blob/master/server/column.go#L41, so we can use hack.Slice instead.

Contributor guide

Research direction
Replace string to []byte conversion with hack.Slice in the Dump function of ColumnInfo in server/column.go to improve performance.
Tech stack
go
Domain
backend
Issue type
Performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Go
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
80