Fottas commented on PR #36370: URL: https://github.com/apache/shardingsphere/pull/36370#issuecomment-3243630955
> Hi @Fottas, this PR looks very complicated. Could you please submit an issue first to describe your design? Hi @strongduanmu: Issue Description: IN Predicate Sharding Optimization Problem: Currently ShardingSphere sends all values in IN predicates to every shard, causing unnecessary data transfer and computation. For example, WHERE id IN (1,2,3,4) is sent as-is to all shards, even though based on sharding keys we can determine that values 1,3 belong to shard A while values 2,4 belong to shard B. Solution: Route-aware IN predicate splitting that distributes values only to their target shards based on sharding algorithms. Technical Design Implementation Principle: Parse each value in IN expressions, invoke existing sharding algorithms to calculate target shards, then rewrite IN clauses for each RouteUnit to contain only values belonging to that shard. Core Components: 1. ShardingInPredicateValue - Encapsulates IN values with their target route information 2. ShardingInPredicateToken - SQL token that rewrites IN clauses per route, filtering values and parameters 3. ShardingInPredicateTokenGenerator - Analyzes IN expressions and calculates shard distribution using existing sharding algorithms 4.ParameterFilterable - Cross-module decoupling interface that enables parameter filtering capability between modules, since ShardingInPredicateToken is in the sharding module while RouteSQLRewriteEngine is in the infra module Key Features: - Supports both standard and complex sharding strategies - Handles parameter markers and literals - Optimizes single-value cases to equality comparisons - Achieves module decoupling through interface abstraction, allowing core engine to work without direct dependencies on - sharding token implementations -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: notifications-unsubscr...@shardingsphere.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
