sql-dao

name	sql-dao
description	SQL data access best practices for AIRBot reviewers
license	MIT

Mission

• Guard database performance and correctness by enforcing disciplined DAO/DAL patterns.
• Catch regressions that risk outages: unbounded queries, missing indexes, unsafe scripts, or misuse of replicas.

Query Execution Standards

• Require explicit column selection (SELECT col1, col2) rather than SELECT *.
• Prefer synchronous flows within jdbi.inTransaction {}; avoid mixing suspend calls inside transactions.
• Enforce batching (@SqlBatch, @BatchChunkSize(2000)) for bulk inserts/updates and chunk large WHERE IN arguments (SQL Server limit ~2200 params).
• Validate pagination on read-heavy endpoints; flag unbounded fetches or N+1 loops.
• Ensure blocking annotations (@BlockingClass, @BlockingCall) exist for DAL/Repo classes and consumers.
• Confirm master vs. replica usage: critical writes/reads hit master; replica lag can reach 30 minutes.

Indexing & Performance

• Request evidence of supporting indexes for new predicates, sort columns, and pagination keys.
• Encourage use of table aliases/prefixes in JOINs to maintain clarity.
• For new queries, verify index coverage and that updated_at timestamps update alongside data mutations.
• Demand UTC handling for timestamps and rely on the database (CURRENT_TIMESTAMP) to set them.

Schema & DDL Expectations

• Ensure PRs document DDL changes and keep migrations incremental/backward compatible.
• Require created_at/updated_at columns, primary keys, and consider unique constraints where appropriate.
• Prefer NVARCHAR over VARCHAR; align column nullability with Kotlin model nullability.
• Advocate for foreign keys to avoid orphaned rows and use online/resumable index operations.

Scripts & Data Ops

• Scripts should live in dedicated packages, run transactional logic in managers/DAL, and treat CLI entrypoints as thin wrappers.
• Verify bulk update scripts log progress, support mockRun, wrap per-row mutations in try/catch, and notify stakeholders before production runs.

Related Stores

• Cosmos DB batches should rely on BulkExecutor; discourage ad-hoc parallel loops.
• RedisCache2 usage must reuse clients, keep TTLs under 6 hours, and avoid local caches that cannot be invalidated.

Tooling Tips

• Grep for SELECT *, @SqlBatch, inTransaction, or AsyncResponse inside DAO code to ensure patterns align.
• Read migration files and DAL implementations to confirm pagination, batching, and index handling.
• Glob *Dao.kt, *Repository.kt, *Script.kt to review related data access or scripting changes together.