Bug Report

Evidence status: confirmed.

1. Minimal reproduce step (Required)

SELECT COUNT(*) FROM information_schema.tikv_region_peers; -- 269
EXPLAIN FORMAT='brief' SELECT * FROM information_schema.tikv_region_peers WHERE region_id = -1; -- MemTableScan without Selection and without region_ids filter
SELECT COUNT(*) FROM information_schema.tikv_region_peers WHERE region_id = -1; -- 269
SELECT COUNT(*) FROM information_schema.tikv_region_peers WHERE CASE WHEN region_id = -1 THEN TRUE ELSE FALSE END; -- 0
SELECT region_id, store_id, peer_id, region_id = -1 AS predicate_value FROM information_schema.tikv_region_peers WHERE region_id = -1 LIMIT 5; -- predicate_value=0 on returned rows
SELECT COUNT(*) FROM information_schema.tikv_region_peers WHERE store_id = -1; -- 269
SELECT COUNT(*) FROM information_schema.tikv_region_peers WHERE CASE WHEN store_id = -1 THEN TRUE ELSE FALSE END; -- 0

2. What did you expect to see? (Required)

A negative region_id/store_id predicate is unsatisfiable for TiKV peer metadata and should return an empty rowset. Invalid or out-of-domain extracted IDs must not bypass the SQL predicate; backend lookup errors for impossible filters should not replace SQL empty-row semantics.

3. What did you see instead? (Required)

The extractor removes the SQL predicate, fails to build a valid uint64 ID filter, and scans all peers. region_id=-1 and store_id=-1 return every row in information_schema.tikv_region_peers; rows visibly fail their own predicate. Non-numeric strings can additionally be coerced to region_ids:[0] and reported as a PD 400 error.

4. What is your TiDB version? (Required)

Confirmed on QA testbed 8192975. SELECT VERSION() returned 8.0.11-TiDB-v8.4.0-this-is-a-placeholder.