5.9 Database operations

14 entries

• 0200 PostgreSQL roles, privileges and default privileges Create login and group roles, grant access to databases, schemas and tables, and use ALTER DEFAULT PRIVILEGES so tables created later get… Intermediate · How-to · Linux Article Roles & administration · Security & access 15 Oct 2026
• 0201 pg_hba.conf and PostgreSQL authentication methods pg_hba.conf decides who may connect from where and how they must prove who they are. Rules are checked top to bottom and… Intermediate · Concept · Linux Article Install & connect · Security & access 15 Oct 2026
• 0209 Fix: FATAL: password authentication failed for user PostgreSQL reached the server and found a matching pg_hba.conf rule, but the password check failed. Usually a wrong password, a role without… Intermediate · Fix · Any system Article Roles & administration · Security & access 15 Oct 2026
• 0210 Fix: FATAL: no pg_hba.conf entry for host The server received the connection but no pg_hba.conf rule matches this client address, user, database and SSL mode. Add or correct a… Intermediate · Fix · Linux Article Install & connect · Security & access 15 Oct 2026
• 0214 MySQL users and privileges: CREATE USER, GRANT and authentication plugins A MySQL account is a user name plus the host it connects from. You create it with CREATE USER, give it rights… Beginner · How-to · Linux Article Administration · Security & access 15 Oct 2026
• 0216 MySQL vs MariaDB: what actually differs MariaDB started as a fork of MySQL and still speaks the same client protocol, but GTIDs, JSON storage, authentication and tooling have… Intermediate · Concept · Linux Article Choosing a database · MySQL & MariaDB 15 Oct 2026
• 0220 Fix: ERROR 1045 (28000): Access denied for user ‘appuser’@’localhost’ (using password: YES) The server rejected the user, host and password combination. Usually it is a wrong password, a host part that does not match,… Beginner · Fix · Linux Article Administration · Security & access 15 Oct 2026
• 0227 Fix: ORA-01017: invalid username/password; logon denied Oracle rejected the login. Check the password (case-sensitive), that you connect to the right PDB service, and whether the account is locked… Intermediate · Fix · Any system Article Administration · Security & access 15 Oct 2026
• 0231 MongoDB documents and collections compared with SQL tables MongoDB stores data as JSON-like documents grouped in collections instead of rows in tables. This explains the model, the _id field, embedding… Beginner · Concept · Any system Article Basics · Choosing a database 15 Oct 2026
• 0233 Turn on MongoDB authentication and create least-privilege users A fresh MongoDB install accepts connections without a password. Create a user administrator, enable authorization, then give each application and backup job… Intermediate · How-to · Linux Article Administration · Security & access 15 Oct 2026
• 0239 Fix: (error) NOAUTH Authentication required. (and securing Redis with ACLs) Redis requires a login and your client sent a command without one. Pass the right user and password, and use the moment… Advanced · Fix · Linux Article Administration & persistence · Security & access 15 Oct 2026
• 0241 Choosing a database: relational, document or key-value Relational databases, document stores like MongoDB and key-value stores like Redis each fit different jobs. An honest look at what each does… Beginner · Concept · Any system Article Choosing a database · Database operations 15 Oct 2026
• 0242 Database security checklist: access, encryption, exposure and patching A practical checklist for hardening any database server, with MongoDB and Redis examples: no public exposure, authentication, least privilege, TLS, protected backups,… Advanced · How-to · Linux Article Database operations · Security & access 15 Oct 2026
• 0243 Database backup strategy: the 3-2-1 rule and testing restores Keep three copies of your data on two kinds of storage with one copy offsite, choose dump or snapshot methods per database,… Intermediate · How-to · Linux Article Database operations · Security & access 15 Oct 2026