SQL Server without a dedicated database administrator: how clients find instances, how to authenticate them with Kerberos, how to keep logins and roles in order, keep an eye on the transaction log and backups, and when the Express edition is enough.
Error 26 after a server restart means the client could not determine the port of a named instance. Where the driver gets the name, port and protocol, when SQL Browser on UDP 1434 is needed, and why current drivers require a trusted server certificate.
Windows authentication in SQL Server keeps working when Kerberos fails, because the client silently falls back to NTLM. How the client builds the SPN, why a named instance needs a static port and its own DNS name, and how to check which protocol applications actually use.
A login lets a connection into the instance, a user grants access to a database, and the two are linked by a SID, not by name. How to build access from directory groups and custom roles, why an application should sign in with a Windows account, and how to fix a user without a login after restoring a database on another server.
A log file more than ten times the size of the data file almost always means a database in the FULL recovery model without log backups. How log truncation works, what log_reuse_wait_desc shows and how to bring the .ldf file back to a sensible size in one go.
A SQL Server service account with a password that never expires and that several people know stays unchanged for years, because changing the password means downtime on every server. How to deploy a group managed service account (gMSA): the KDS root key, the account, installation on the servers and the account change in SQL Server Configuration Manager.
SQL Server Express has no SQL Server Agent and no maintenance plans, so backups have to be scheduled some other way. A PowerShell script with sqlcmd run from Task Scheduler under a gMSA, file retention, and restoring log backups on a second server as an equivalent of log shipping.
Express has three hard limits: database size, buffer pool memory and the number of cores, and it has no SQL Server Agent, backup compression or high availability. How to measure which limit actually blocks work, how the SQL Server 2025 editions differ, and when to move to Standard.