Category: Troubleshooting

SQL Server error 15517, cannot execute as the database principal. Why dbo maps to an orphaned owner after a restore and the one-line fix.

Nothing is broken when you see 468. Two sides of a comparison store text under different rules, and SQL Server will not guess which should win. The fix is one line, and it does not belong on the column.

823 means the storage failed the read and said so. 824 means it succeeded and the data was wrong. Which one you have changes who you escalate to, and what you protect first.

3417 is the summary, not the diagnosis. Four kinds of master damage reproduced in a throwaway container, and 3417 appeared in none of them. Here is what each one actually logs.

🚨Part of the SQL Server Errors series, the exact messages and what actually causes them. Msg 15138  ·  Level 16  ·  State 1 The database principal owns a schema in the database, and cannot be dropped. Msg 15138, Level 16, State 1 ⚡Reassign, then drop. ALTER AUTHORIZATION ON SCHEMA::[name] TO [dbo] clears it, but check…

3013 is never the cause, it is the last line of a failed restore. Five restore failures reproduced in a container, five different real errors above it, and three of them had nothing wrong with the backup file.

701 is the server unable to find memory at all. 8645 is the memory existing and being held by someone else. Neither one means buy more RAM, and cumulative wait stats will mislead you about both.

🚨Part of the SQL Server Errors series, the exact messages and what actually causes them. Msg 3154  ·  Level 16  ·  State 4 The backup set holds a backup of a database other than the existing ‘Sales’ database. Msg 3154, Level 16, State 4 RESTORE DATABASE is terminating abnormally. ⚡Restore alongside rather than over the…

🚨Part of the SQL Server Errors series, the exact messages and what actually causes them. Msg 5030  ·  Level 16  ·  State 2 The database could not be exclusively locked to perform the operation. Msg 5030, Level 16, State 2 ⚡Never end a session with the database still in SINGLE_USER. An application pool takes the…

Msg 102 usually is not a typo. If the same statement runs on one database and fails on another, the parser grammar is chosen by compatibility level, not by the version of the instance.