SQL DBA Blog: Home
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Restore Testing: Proving the Backups Actually Work
A backup you have never restored is a hypothesis. What coverage checks prove, what they do not, and how to run a restore drill that measures your real recovery time.
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The First Hour on a SQL Server You Have Never Seen
Four questions in order: what is this, what is it supposed to do, what is it short of, and what is unprotected. The order matters more than the speed, and nothing gets changed.
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Linked Server Login Failed for NT AUTHORITY\ANONYMOUS LOGON
A linked server that works on the server and fails from your desktop is the double hop. The query that proves it, the four login mappings and what each one fails with, plus error 7391 and MS DTC.
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SQL Server Agent Jobs Queued on Maximum User Working Threads (Fix)
SQL Server Agent jobs queued with message [398]: how to see what is waiting for a thread right now, which of 3 similarly named limits you hit, and the Windows desktop heap value that cleared it on a clustered distributor.
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Cumulative Wait Stats Lie: Measuring Waits Over an Interval
Wait statistics accumulate from startup, so on a long-running instance they describe history rather than the problem in front of you. Two snapshots and a subtraction fix that.
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SQL Server Cannot Obtain a LOCK Resource at This Time (Error 1204)
SQL Server cannot obtain a LOCK resource at this time. What error 1204 actually means, the 1 query and the 1 ERRORLOG line that find the cause, and the fix in the order worth trying.
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SQL Server Differential vs Log Backup: Which One Restores What, and How the Chain Breaks
Mid restore is the wrong moment to work out how differential and log backups differ. What each one contains, which files you actually need, and the trap that any ordinary full backup taken by anyone silently becomes the new base for your differentials.
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SQL Server MAXDOP and Cost Threshold: What To Set, and Why 5 Is Not a Recommendation
Two settings decide when SQL Server splits a query across processors, and both ship with values you are probably meant to change. Microsoft’s current MAXDOP table, what they actually say about cost threshold, and why CXPACKET is no longer the evidence it used to be.
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SQL Server Log Won’t Truncate: What log_reuse_wait_desc Is Telling You
A transaction log is filling a disk and the backup job says it succeeded. SQL Server already knows why it cannot reuse the space, and it tells you in one column of sys.databases.
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sp_who vs sp_who2 vs sp_whoisactive in SQL Server
Ever wondered what is happening inside your SQL Server instance right now? sp_who, sp_who2 and sp_whoisactive all answer that question, at very different depths. The first ships documented, the second ships undocumented but better, and the third is a free community procedure that most working DBAs treat as the real answer. This post is the…
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- SQL Server Configuration Manager: Where to Find It and What a DBA Uses It For
- DBA Scripts: Get Failed Login Summary
- Query Was Fast Yesterday, Slow Today: Find What Changed
- The Current Transaction Cannot Be Committed (Error 3930)
- Sort and Hash Spills to TempDB: Find the Query and Fix the Grant
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