DashBoard/openspec/changes/archive/2026-03-02-unified-batch-query-redis-cache/specs/reject-history-api/spec.md

MODIFIED Requirements

Requirement: Database query execution path

The reject-history service (reject_history_service.py and reject_dataset_cache.py) SHALL use read_sql_df_slow (dedicated connection) instead of read_sql_df (pooled connection) for all Oracle queries. For large queries, BatchQueryEngine SHALL decompose by time range or ID count.

Scenario: Primary query uses dedicated connection

• WHEN the reject-history primary query is executed
• THEN it uses read_sql_df_slow which creates a dedicated Oracle connection outside the pool
• AND the connection has a 300-second call_timeout (configurable)
• AND the connection is subject to the global slow query semaphore

Scenario: Long date range triggers time decomposition (date_range mode)

• WHEN the primary query is in date_range mode and the range exceeds 60 days (configurable via BATCH_QUERY_TIME_THRESHOLD_DAYS)
• THEN the query SHALL be decomposed into ~31-day monthly chunks via BatchQueryEngine.decompose_by_time_range()
• THEN each chunk SHALL execute independently with the chunk's date sub-range as bind parameters
• THEN chunk results SHALL be stored individually in Redis and merged via pd.concat

Scenario: Large container ID set triggers ID decomposition (container mode)

• WHEN the primary query is in container mode (workorder/lot/wafer_lot input) and the resolved container ID count exceeds 1000
• THEN the container IDs SHALL be decomposed into 1000-item batches via BatchQueryEngine.decompose_by_ids()
• THEN each batch SHALL execute independently
• THEN batch results SHALL be merged into the final cached DataFrame

Scenario: Short date range or small ID set uses direct query

• WHEN the date range is 60 days or fewer, or resolved container IDs are 1000 or fewer
• THEN the existing single-query path SHALL be used without engine decomposition

Scenario: Memory guard on result

• WHEN a chunk query result exceeds BATCH_CHUNK_MAX_MEMORY_MB
• THEN the chunk SHALL be discarded and marked as failed
• THEN the current limit: 999999999 pattern SHALL be replaced with a configurable max_rows_per_chunk