Db Performance

---
name: db-performance
description: "Производительность БД и запросов 1С. Используй когда нужно диагностировать slow query, SQL/DBMS trace, индексы, блокировки, deadlock, TEMPDB/WAL, размеры таблиц или СКД на больших данных."
---

# DB Performance

## MCP routing

- Preferred path: use MCP `unica` tools `unica.view {}`, `unica.search`, `unica.view` on the object node, `unica.view` on the schema node, `unica.check`, `unica.docs`, and `unica.run`.
- Runtime идёт через `unica.run`: вызов без `op` отдаёт словарь операций и
контракт каждой — `argsSchema`, `execution`, `previewRequired`,
`dryRunRequired`. Контракт вызова бери оттуда, а не из этого текста;
при `implemented: true` используй опубликованную `argsSchema`; при
`support.state: limited` разрешено только подмножество `support.supportedArgs`.
При `support.state: unavailable` остановись; не выдумывай аргументов при
`argsSchema: null`. Для плановой операции сначала проверь результат `dryRun: true`,
затем исполняй запрос с `dryRun: false`. Preview не фиксирует входы между
вызовами. Не обходи контракт прямым runner-ом.
- Use `unica.view` on the role node when performance behavior depends on rights filters, RLS, or tenant boundaries.
- Do not call internal analyzer, runtime, standards, or package adapters directly. They are hidden behind MCP `unica`.

## References

- Read `../../references/platform/db-performance.md` for DB-aware workflow, indexes, virtual tables, locks, and DBMS evidence.
- Read `../../references/platform/runtime-diagnostics.md` when performance evidence comes from ЖР/ТЖ, process ids, sessions, or runtime timeline.
- Read `../../references/platform/transactions-locks.md` once evidence points at contention; this skill keeps the evidence side, that document owns the lock and transaction rules.

## Workflow

1. Name the slow scenario first: user action, API call, report, background job, exchange step, or posting.
2. Extract exact query/DCS text with `unica.search` or `unica.view` on the schema node; inspect large candidate modules with `unica.view` on the module node (its `Method` branch lists the methods) before reading full bodies.
3. Find callers with `unica.search` by the method name when the performance issue depends on execution path, query-in-loop risk, or impact of moving logic; a call graph is not on the v0.13 surface.
4. Inspect `unica.view` on the object node for both the local object structure and related modules, roles, subscriptions, functional options, or predefined items that can change the performance path.
5. Gather evidence: row counts, generated SQL, query plan, managed locks, lock order, lock/deadlock participants, long transaction boundaries, temp storage, TEMPDB or WAL pressure, and table/index names.
6. Separate causes: inefficient platform query, missing or harmful index, broad virtual table read, query-in-loop, lock contention, DBMS maintenance, or data growth.
7. Propose one measurable change at a time; check syntax with `unica.check` (test runs are outside the v0.13 surface), and require separate runtime plus timing/DBMS evidence before calling the change verified.

## Stop rules

- Do not recommend indexes without a concrete predicate, join, sort, grouping, and write-cost tradeoff.
- Do not remove rights filters, tenant filters, or `РАЗРЕШЕННЫЕ` for performance without a named security decision.
- Do not claim a DBMS root cause without DBMS evidence. State missing evidence or Unica MCP contract gap.

## Output

- Scenario and evidence summary.
- Root cause ranked by likelihood.
- Minimal query/metadata/code change.
- Verification command or measurement.
- Residual risk for data volume, locks, or DBMS-specific behavior.