Data / SQL

SQL / Databases

SQL Server, MySQL, MariaDB and PostgreSQL administration and troubleshooting for connections, performance, blocking, backups, logs and storage.

SQL ServerMySQLPostgreSQLDeadlocksBackupPerformanceLogs

2BAOI modules

23selected resources

6definitions

Tools & diagnostics

Direct access to the most relevant BAOI modules for this technology.

Troubleshooting SQL / Databases Center

Diagnostic SQL Server, MySQL/MariaDB et PostgreSQL : services, connexions, authentification, blocages, deadlocks, performances, logs, sauvegardes et espace disque.

Open → Troubleshooting WordPress Center

WordPress diagnostic: critical error, 500, database, permalinks, SMTP, cron, plugins, WordPress, SSL and performance.

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Dictionary

Essential concepts related to SQL / Databases.

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Dictionary SQL Server Always On Availability Groups

A Web, API, DNS, or database concept used to transport, expose, or protect application data.

View → Dictionary SQL Server Failover Cluster Instance

A Web, API, DNS, or database concept used to transport, expose, or protect application data.

View → Dictionary Vector Database

A Web, API, DNS, or database concept used to transport, expose, or protect application data.

View → Dictionary Vector Database AI

An AI or data concept used to build, steer, or connect models and their knowledge.

View → Dictionary Known Error Database (KEDB)

An ITSM or monitoring concept used to organize support, changes, and service quality.

View → Dictionary Public Key Pinning

A Web, API, DNS, or database concept used to transport, expose, or protect application data.

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Practical guides

Step-by-step tutorials and procedures.

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Guide How to diagnose MySQL error 1213 deadlocks

This BAOI guide provides a structured method for diagnosing mysql 1213-2.

View → Guide How to deploy DMARC gradually without blocking legitimate emails

A DMARC policy must be gradually deployed to identify all legitimate sources before moving to the quarantine or the mundane.

View → Guide How to remove stale Exchange Autodiscover references

This BAOI guide provides a structured method for cleaning an old auto-Catch exchange without multiplying unnecessary changes.

View → Guide How to troubleshoot AADSTS53003 in Microsoft Entra ID

Identify the exact Conditional Access policy blocking a sign-in without creating a broad exclusion.

View → Guide How to analyze an Auto-Divd problem

Auto SQL is often at the heart of Outlook or d profile creation problems, old Exchange environments.

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Troubleshooting

Related failures, errors and diagnostics.

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Error code MySQL 1213 — Deadlock found

Transactions are blocking each other and one has to be cancelled.

View → Error code MySQL 2002 — Can’t connect to local server

The client cannot reach the local MySQL server.

View → Error code MySQL 1045 — Access denied for user

MySQL or MariaDB refuses the authentication of, user.

View → Error code MySQL 1205 — Lock wait timeout exceeded

One transaction is waiting too long for a lock held by another transaction.

View → Error code BDD Connection Facility — Error when establishing the connection to the database

WordPress no longer manages to connect to MySQL or MariaDB.

View → Error code WordPress — Error establishing a database connection

WordPress does not manage to connect to its database.

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Field procedures

Reusable intervention methods.

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Procedure Respond to a suspected compromised Microsoft 365 account

Contain a suspected compromised Microsoft 365 account by collecting sign-in evidence, blocking access, revoking sessions, resetting credentials, reviewing…

View → Procedure Properly offboard a Microsoft 365 user

Offboard a Microsoft 365 user without losing data by blocking sign-in, revoking sessions, preserving mailbox and OneDrive content, reviewing delegations, d…

View → Procedure Deploy an Intune compliance policy

Create a Windows compliance policy in Microsoft Intune, define measurable criteria, pilot non-compliance actions and then use compliance status in Conditio…

View → Procedure Protect an API with rate limiting

Deploy a API limiting spleen without blocking legitimate customers: reference metrics, relevant key, dry-run NGINX,199, code 429 tests and observability.

View → Procedure Deploy MTA-STS and TLS-RPT

Deploy MTA-STS and SMTP TLS-Dress without blocking reception: audit section boroughTLS/MX, HTTPS policy in test mode, DNS records, TLS-RPT reports, progres…

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Cheat sheets

Quick references for operations.

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Cheat sheet WordPress — Express troubleshooting

Incident-focused WordPress reference for logs, plugins, themes, database, WP-CLI, cron, permalinks, SMTP, permissions and 500/critical errors.

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Related technologies

Continue exploring with complementary topics.

Technology Windows Server

Windows Server diagnostics and administration for services, RDP, storage, VSS, Event IDs, PowerShell, certificates and updates.

View → Technology Linux

Linux commands, diagnostics and resources for Debian, Ubuntu, Bash, systemd, SSH, files, networking, logs and backups.

View → Technology Backup & Disaster Recovery

Backup, restore and disaster recovery resources for Veeam, Acronis, VSS, RPO, RTO, immutability, replication and restore testing.

View → Technology Storage / NAS / SAN

Enterprise storage resources for RAID, SMART, NAS, SMB/NFS, iSCSI, MPIO, LUNs, SAN, ZFS, LVM, snapshots, capacity and performance.

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