Feat: cache infoschema #772

Song-Quan · 2026-01-04T03:38:05Z

缓存 infoschema 来加速 select、create view 之类语句

gemini-code-assist · 2026-01-04T03:38:23Z

Summary of Changes

Hello @Song-Quan, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

此拉取请求旨在通过引入信息模式 (infoschema) 缓存机制来显著提升数据库操作的性能，特别是针对 SELECT 和 CREATE VIEW 等语句。通过缓存常用的信息模式数据并确保在 DDL 操作后及时更新缓存，系统可以减少对底层数据库的频繁查询，从而提高响应速度和整体效率。

Highlights

引入信息模式缓存: 在 pkg/scdb/storage/storage.go 中引入了一个 sync.Map (infoSchemaCache) 来缓存数据库的信息模式 (infoschema)，并添加了缓存命中/未命中统计。
实现缓存失效机制: 新增 InvalidateInfoSchemaCache 函数，用于根据数据库名称清除特定缓存或清空所有缓存。
集成缓存到查询逻辑: 修改 QueryDBInfoSchema 函数，使其在查询信息模式时首先检查缓存，如果未命中则从数据库查询并存入缓存。
DDL操作后缓存失效: 在 pkg/scdb/executor/ddl.go 和 pkg/scdb/storage/schema_tables.go 中，为 CREATE DATABASE, CREATE TABLE, CREATE VIEW, DROP DATABASE, DROP TABLE 等 DDL 操作成功后添加了调用 InvalidateInfoSchemaCache 的逻辑，确保缓存数据的一致性。

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Code Review

本次 PR 引入了 infoschema 缓存机制，旨在提升 select、create view 等语句的执行效率，这是一个很好的优化。代码整体实现不错，但在并发安全、代码冗余和性能方面还有一些可以改进的地方。我主要提出了以下几点建议：

修复了 InvalidateInfoSchemaCache 中一个严重的竞态条件问题。
指出了 ddl.go 中存在的多余的缓存失效调用，并建议移除。
建议使用 sync/atomic 来优化缓存命中/未命中计数器的性能，以减少锁竞争。

pkg/scdb/storage/storage.go

pkg/scdb/executor/ddl.go

pkg/scdb/storage/storage.go

Copilot

Pull request overview

This PR introduces an InfoSchema caching mechanism to improve query performance for operations like SELECT and CREATE VIEW by reducing database queries. The implementation adds a cache layer with automatic invalidation on schema-modifying DDL operations.

Key Changes:

Implements InfoSchema caching using sync.Map with cache hit/miss statistics tracking
Adds cache invalidation hooks to all DDL operations (CREATE/DROP database, table, and view)
Provides utility functions for cache management and statistics retrieval

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 9 comments.

File	Description
pkg/scdb/storage/storage.go	Adds cache infrastructure with `sync.Map`, statistics tracking, and cache invalidation/query functions
pkg/scdb/storage/schema_tables.go	Adds cache invalidation calls to DropSchema and DropTable operations
pkg/scdb/executor/ddl.go	Adds cache invalidation calls to all DDL executor methods (create/drop database, table, view)

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pkg/scdb/storage/storage.go

pkg/scdb/executor/ddl.go

pkg/scdb/storage/storage.go

jingshi-ant · 2026-01-05T08:59:58Z

pkg/scdb/executor/ddl.go

 		}
 	}
+
+	storage.InvalidateInfoSchemaCache(dbName)


invalid的操作直接在调用 executeCreateView 的层级上统一做应该会更简洁。

jingshi-ant · 2026-01-05T09:00:54Z

pkg/scdb/storage/storage.go

+}
+
+// GetInfoSchemaCacheStats returns cache hit and miss statistics
+func GetInfoSchemaCacheStats() (hits, misses int64) {


这两个func只是为了测试用吗？可以看看是否适合加到metrics里面

Song-Quan added 2 commits January 4, 2026 03:32

cache infoschema

b7825b6

drop cache when schema changed

9269028

Song-Quan requested a review from Copilot January 4, 2026 03:38

Copilot started reviewing on behalf of Song-Quan January 4, 2026 03:38 View session

gemini-code-assist bot reviewed Jan 4, 2026

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Copilot AI reviewed Jan 4, 2026

View reviewed changes

Song-Quan added 2 commits January 4, 2026 03:46

add ut & remove unnecessary comments

3503a6e

opt lock

20b6b18

Song-Quan marked this pull request as ready for review January 5, 2026 03:03

Song-Quan requested a review from a team January 5, 2026 03:10

jingshi-ant reviewed Jan 5, 2026

View reviewed changes

Song-Quan added the run-ci-full run ci on multiple platforms label Jan 5, 2026

github-actions bot removed the run-ci-full run ci on multiple platforms label Jan 5, 2026

concentrate invalidate

518a618

Song-Quan added run-ci run-ci-cov and removed run-ci labels Jan 5, 2026

github-actions bot removed the run-ci-cov label Jan 5, 2026

Song-Quan added 5 commits January 5, 2026 11:57

infoschema cache configurable

7e4d13f

enable infoschema cache

a4d9d9e

add ut

0283252

Merge branch 'main' into feat/infoschema-cache

c6f3087

fix go lint & update config ut

4b90c31

Song-Quan requested a review from a team January 6, 2026 07:47

Song-Quan mentioned this pull request Jan 6, 2026

SCQL grant特别慢 #770

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Feat: cache infoschema #772

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Feat: cache infoschema #772

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Song-Quan commented Jan 4, 2026

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