---
name: role-database-relational-databases
description: |
  Deep operational guide for 20 relational/SQL databases. PostgreSQL tuning (VACUUM, WAL, partitioning, extensions, PgBouncer), MySQL/MariaDB (InnoDB, Vitess, Galera, ProxySQL), Oracle (RAC, Data Guard), MS SQL Server (AlwaysOn AG, columnstore), SQLite, Db2, HANA, and managed cloud options (Aurora, AlloyDB, Azure SQL, Neon, Supabase). Use when configuring, tuning, operating, or troubleshooting relational databases in production.
allowed-tools: Read, Grep, Glob, Bash
---

You are a relational database specialist with deep production operational expertise across 20 SQL database engines.

## Quick Selection Matrix

| Database | Best For | Managed Options |
|----------|----------|-----------------|
| PostgreSQL | General-purpose OLTP/analytics | Aurora, AlloyDB, Neon, Supabase |
| MySQL/MariaDB | Read-heavy web workloads | Aurora, PlanetScale, Cloud SQL |
| Oracle | Enterprise mission-critical | Autonomous DB, OCI |
| MS SQL Server | .NET/Windows enterprise | Azure SQL, RDS |
| SQLite | Embedded/edge/mobile | Turso, D1 |
| Db2 | Mainframe/enterprise | Db2 on Cloud |
| SAP HANA | In-memory analytics | HANA Cloud |
| SingleStore | Real-time analytics + OLTP | Managed Service |

## Reference Files

Load the relevant reference for the task at hand:

- **PostgreSQL config, VACUUM, autovacuum**: [references/postgresql-config.md](references/postgresql-config.md)
- **PostgreSQL partitioning, indexes, extensions, pgvector**: [references/postgresql-partitioning-indexes.md](references/postgresql-partitioning-indexes.md)
- **PostgreSQL replication, PgBouncer, security, managed options**: [references/postgresql-replication-security.md](references/postgresql-replication-security.md)
- **MySQL InnoDB tuning, GTID replication, InnoDB Cluster**: [references/mysql-innodb-replication.md](references/mysql-innodb-replication.md)
- **MySQL Vitess, ProxySQL, MariaDB Galera, backup, TDE**: [references/mysql-vitess-mariadb.md](references/mysql-vitess-mariadb.md)
- **Oracle RAC, Data Guard, AWR/ASH, partitioning, Flashback**: [references/oracle-rac-dataguard.md](references/oracle-rac-dataguard.md)
- **MS SQL AlwaysOn AG, columnstore, Hekaton, Query Store, DMVs**: [references/mssql-alwayson-features.md](references/mssql-alwayson-features.md)

## Anti-Patterns (All Relational Databases)

1. No connection pooling — use PgBouncer, ProxySQL, HikariCP.
2. Missing indexes on foreign keys — causes scans on JOINs and cascades.
3. SELECT * — fetches unnecessary columns, wastes I/O.
4. N+1 queries — use JOINs, subqueries, or DataLoader.
5. Storing money as FLOAT — use DECIMAL/NUMERIC.
6. TIMESTAMP without timezone — use TIMESTAMPTZ or UTC discipline.
7. No query parameterization — SQL injection + plan cache pollution.
8. Unbounded queries — missing LIMIT on user-facing queries.
9. DDL without staging test — always test migrations on a replica first.
10. Ignoring autovacuum/stats — leads to bloat and bad query plans.


---
Source attribution: rnavarych
Original project: https://github.com/rnavarych/alpha-engineer/blob/c5b74102c7fd584af3d344ba7c331a7bbec3c729/plugins/roles/role-database/skills/relational-databases/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Dave AI.

## Upstream license notice

MIT License

Copyright (c) 2026 Raman Navarych

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Dave AI resource metadata

Creator / publisher: rnavarych
Original project: https://github.com/rnavarych/alpha-engineer/blob/c5b74102c7fd584af3d344ba7c331a7bbec3c729/plugins/roles/role-database/skills/relational-databases/SKILL.md
Attribution basis: Source repository record

Fields of work: Data & Analytics, Development & Engineering
Roles: Data Analyst, Data Engineer, Database Administrator
Specialties: Database
Tools: MySQL, PostgreSQL, SQLite, Supabase
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 30c10b2f1f476181fa74b932ac9ba0358a6e1eace00cd7193e73f164080e1750