Aurélien LEQUOY
Senior Database Architect — MariaDB / MySQL / High Availability
20+ years building and rescuing mission-critical MariaDB/MySQL platforms worldwide. Founder of PmaControl, an advanced observability & automation suite. Specialist in Galera Cluster, high availability, performance engineering, and zero-downtime migrations.
Paris, France • Worldwide
email
+33 6 63 28 27 47
LinkedIn
French • English
GitHub → PmaControl
Aurélien Lequoy
Executive Summary

Senior DBA & Architect specializing in MariaDB, MySQL, Oracle and high-availability solutions. I intervene in complex production environments: performance crises, cluster failures, HA redesign, secure migrations, and large-scale automation.

My approach is observability-driven (PmaControl, real-time telemetry, replay), highly pragmatic, and incident-focused.

Signature Capabilities
MariaDB / MySQL
  • Advanced performance engineering (queries, indexes, CPU/memory/I/O).
  • Replication topologies: GTID, multi-source, semi-sync, cross-DC.
  • Galera Cluster design, tuning & rescue (segments, IST/SST, gcache).
  • Severe crash recovery: corrupted InnoDB, lost nodes, broken backups, DC disasters.
Oracle
  • Run DBA, PL/SQL and execution plan optimization.
  • DataGuard (physical/logical), switchover/failover & PRA drills.
  • RMAN backup architecture: full/incr/archivelog, PITR.
  • Oracle ↔ MySQL/MariaDB heterogeneous migrations.
Recent Experience (Top)
PmaControl — Founder & Lead Architect
Feb 2024 – Present • Worldwide
  • EngineV4 real-time topology + replay of overnight incidents.
  • AI-assisted slow query autotuning (local LLM).
  • Full ProxySQL/MaxScale support and HA diagnostics.
  • RocksDB-backed time-series ingestion at high scale.
Worldline — Senior DBA MySQL/MariaDB/Oracle
Apr 2023 – Dec 2023 • Lille
  • MySQL 5.7→8 & InnoDB Cluster upgrades without downtime.
  • Oracle run DBA, backup standardization, GR deployment automation.
CNFPT — Galera Cluster Rescue (0 downtime)
May–Jun 2024 • Paris
  • Recovered a collapsed Galera cluster with corrupted final node.
  • Low-level data salvage, rebuild, hot cutover.
Landscape One-Pager • Export PDF from Chrome with “Background graphics”.
Skills Portfolio — Detailed Competencies
MariaDB / MySQL / Oracle / HA / Performance / Recovery / Automation
Selected technical capabilities built over 20+ years of high-stakes production missions.
Aurélien LEQUOY
Senior DBA / Architect
Worldwide missions
Performance & Storage Engineering (MariaDB/MySQL)
  • Holistic performance engineering: end-to-end tuning of queries, indexes, buffer pool, log subsystem, CPU/memory pressure, I/O scheduling, NUMA considerations, and network latency.
  • Deep InnoDB internals expertise: redo/undo lifecycle, flushing heuristics, adaptive flushing, doublewrite behavior, page formats, corruption identification and low-level page recovery.
  • RocksDB/MyRocks advanced tuning: block cache sizing, compaction strategies, WAL configuration, rate-limiting, bloom filters, and partitioning for high-ingestion time-series workloads.
  • Spider engine sharding & distributed queries at extreme scale (XA semantics, remote tables, query fan-out, parallel reads, cross-partition consistency guarantees).
  • High-volume bench & storage modeling: tests up to 100B+ rows with RocksDB + Spider, evaluating compaction impact, LSM write amplification, and cold/warm cache behavior.
  • Optimizer-level analysis: histograms, semijoin/inner-join strategies, derived table merging, range vs ref optimizations, subquery materialization, and plan regression prevention.
  • Advanced binlog engineering: retention strategies, parallel replication tuning, transaction write-set ordering, relay log I/O pressure mitigation, and GTID failover safety.
  • Write-intensive workload stabilization: redo/undo pressure control, adaptive flushing calibration, flush_neighbors strategy tuning, and mitigation of checkpoint stalls under OLTP bursts.
  • Page-level behavior analysis under high write load: LRU eviction patterns, doublewrite tuning, I/O fusion, dirty page pressure, and flushing models for SSD/NVMe tiers.
  • Engine interoperability & workload matching: expert-level selection and tuning across InnoDB, RocksDB/MyRocks, Aria, and Spider — based on read/write ratio, latency profile, compaction behavior, durability requirements, and data distribution models.
  • Galera cluster performance deep-dive: flow control tuning, gcache and IST management, wsrep write-set handling, certification overhead analysis, parallelization strategies, cross-datacenter latency mitigation, and avoiding cluster-wide stalls under high load.
Severe Crash & Data Recovery (MariaDB/MySQL)
  • Recovery after severe production failures: corrupt InnoDB pages/indexes, broken tablespaces, FS corruption, multiple node loss.
  • Reconstruction using remaining healthy pages, dictionary rebuild, and transaction replay.
  • Binlog/GTID reconstruction to restore consistency and minimize data loss.
  • Disaster scenarios: partial datacenter loss including fire events, loss of backups, restore from offsite + log shipping + emergency topology rebuild.
  • Objective: fastest possible RTO, minimal RPO, documented post-mortem.
Oracle (Run / HA / Backup)
  • Run DBA responsibilities on critical Oracle estates.
  • Performance tuning: AWR/ASH, execution plans, SQL tuning sets, PL/SQL optimization.
  • DataGuard physical/logical: design, standby redo logs, apply monitoring, switchover/failover automation, PRA drills.
  • RMAN backup strategy: full/incremental/archivelog, duplication, transport TS.
  • Point-In-Time Recovery (PITR) to recover after human error or corruption.
  • Heterogeneous migrations Oracle ↔ MySQL/MariaDB.
Detailed Competencies • Page 2
Automation, Observability & Service Catalog
PmaControl / EngineV4 / Time-series / CI/CD
Industrialization of operations, telemetry, and proactive incident management.
Aurélien LEQUOY
Senior DBA
Senior Architect
Service Catalog
Audit / Health-Check
  • Configuration, schema, workload, HA, backup, security.
  • Prioritized action plan + roadmap.
Performance Engineering
  • Crisis resolution, optimizer tuning, indexing/partitioning.
  • Capacity planning & benchmarks.
High Availability Design
  • Galera / replication / GR / DataGuard architectures.
  • PRA/PCA strategy and tests.
Zero-Downtime Migration
  • MySQL/MariaDB major upgrades with hot cutover.
  • Oracle ↔ MariaDB/MySQL heterogeneous migrations.
Rescue Mission
  • Cluster down, corruption, replication broken.
  • Low-level recovery and emergency rebuild.
Training
  • DBA Admin, Performance, HA Galera, ProxySQL/MaxScale.
  • 3-day hands-on workshops (install + ops + troubleshooting).
Methodology
  • Phase 0 – Rapid framing (1–2h): context, SLA, volumetry, access & risks.
  • Phase 1 – Diagnosis: metrics extraction, logs, schema & workload analysis.
  • Phase 2 – Quick wins: immediate safe fixes to stabilize production.
  • Phase 3 – Structured remediation: tuning, HA redesign, automation.
  • Phase 4 – Validation: load tests, failover/PITR/restore drills, runbooks.
Standard Deliverables
  • Audit report (PDF): findings, risks, priorities, quick wins, roadmap.
  • HA / PRA / backup detailed plans.
  • Automation scripts (Git), documented, production-ready.
  • Runbooks and operational guidelines.
  • Knowledge transfer & team training.
Automation & Services • Page 3
Experience & Major Missions
Selected engagements — Worldwide
High-impact missions in finance, cloud, telecom, public sector, and high-scale SaaS.
Aurélien LEQUOY
Senior DBA / Architect
Major Legacy Missions
CNFPT — Galera Cluster Rescue (2024)
Cluster collapsed (2 nodes lost + last node corrupted). Low-level salvage, rebuilt cluster and hot cutover with zero downtime.
Worldline — Senior DBA MySQL/MariaDB/Oracle (2023)
MySQL 5.7→8 & InnoDB Cluster upgrades without interruption, automated GR deployment, Oracle run DBA in multi-DB environment, unified backup & purge tooling.
Payplug / Dalenys — GCP Migration & HA (2022–2023)
Migrated heterogeneous platform to GCP with ProxySQL + Orchestrator HA. Production ownership over ~100 servers across environments.
OVHcloud — Non-standard MariaDB Architectures (2020–2021)
Owner of all Galera/custom replication solutions. Fixed replication lag, designed HA patterns, and deployed Patroni clusters for PostgreSQL.
Visa Europe — PCI-DSS / Encryption / Galera Architect (2017)
Tablespace+binlog encryption, key rotation, ClusterControl integration, segment-based clustering, ultra-fast purge scripts without contention.
RueDuCommerce — Hot Migrations & HA (2017–2019)
Hot migration MySQL 5.1/5.5/10.0/10.1 → MariaDB 10.3 without downtime, Galera+HAProxy, archiving tools, automatic binlog retention, PmaControl v2.
Saint-Gobain — Big Data Storage Tests (2017)
Benchmarked RocksDB + Spider for extreme volumetry (100B+ rows), architecture guidance and model adaptation.
EDF / Alstom — Oracle DBA & Migration Lead (2010–2014)
Oracle server deployment, MySQL→Oracle migrations, PL/SQL performance, technical leadership for high-volume financial applications.
Education
IUT du Havre — Computer Science (2001–2003)
Experience & Impact • Page 4