SQL Server Performance, Transaction, and Replication Operations Knowledge
From statistics, wait types, transactions, and log files to CDC, replication, linked servers, and TLS connections — practical checks for SQL Server production operations, with SQL included.
- SQL ServerMediumSQL to Check Statistics Last-Updated Time per Table in SQL ServerA read-only SQL script using sys.stats and STATS_DATE that lists the last-updated time and the number of rows modified since the last update, per table and statistic.Last Verified 2026-08-13
- SQL ServerRead-onlyHow to Check Transaction Log Usage on RDS for SQL ServerA read-only procedure that checks log usage with DBCC SQLPERF(LOGSPACE) and sys.dm_db_log_space_usage, and isolates the reason it is not being released using log_reuse_wait_desc.Last Verified 2026-08-13
- SQL ServerHighSQL to Check for Long-Running Open Transactions in SQL ServerA procedure using the sys.dm_tran_active_transactions family of DMVs to identify abandoned transactions, including start time, session, and the last SQL statement executed.Last Verified 2026-08-13
- SQL ServerMediumCauses and Checks for High CXPACKET Waits in SQL ServerA procedure for evaluating CXPACKET using sys.dm_os_wait_stats and sys.dm_os_waiting_tasks, distinguishing it from CXCONSUMER, and moving toward a review of the degree of parallelism.Last Verified 2026-08-13
- SQL ServerMediumHow to Check and Change MAXDOP and Cost Threshold for Parallelism in SQL ServerA procedure for checking and changing the degree of parallelism at the server, database, and query levels, along with the differences in scope and impact at each level.Last Verified 2026-08-13
- SQL ServerExpert Review RequiredHow to Check Whether CDC Log Scanning Has Stopped in SQL ServerA procedure for checking whether CDC's log scan is progressing, using sys.dm_cdc_log_scan_sessions, cdc.lsn_time_mapping, and the state of the capture job.Last Verified 2026-08-13
- SQL ServerExpert Review RequiredWhy MSrepl_commands Keeps Growing in SQL Server, and How to Check for Replication LagA procedure for isolating a backlog of commands in the distribution database from two angles: the state of the distribution agent, and the cleanup job / retention period.Last Verified 2026-08-13
- SQL ServerHighCauses and Checks for Msg 7356 on a Linked Server in SQL ServerMsg 7356 signals that column metadata disagreed between compile time and run time. This organizes how to isolate the cause and how to work around it using pass-through queries.Last Verified 2026-08-13
- SQL ServerMediumWhy TLS 1.2 Connections Fail with SQLNCLI10, and Migrating to MSOLEDBSQL 19This separates connection failures caused by SQLNCLI10's lack of TLS 1.2 support from those caused by MSOLEDBSQL 19's default changing to Encrypt=yes, and organizes what to check during migration.Last Verified 2026-08-13
- SQL ServerHighThe Difference Between DBCC SHRINKDATABASE and DBCC SHRINKFILE, and What to Check Before Running ThemOrganizes the difference between SHRINKDATABASE, which targets the whole database, and SHRINKFILE, which targets a single file; when to use TRUNCATEONLY; and what to check before running either.Last Verified 2026-08-13
- SQL ServerHighCauses and Countermeasures for Disk I/O Performance Degradation After Migrating an On-Premises SQL Server to AWSOrganizes the causes of disk I/O performance degradation due to structural differences between on-premises physical NVMe/SSD and AWS EBS, and four practical countermeasures: buffer pool maximization, data compression, file separation, and CDC log bloat response.Last Verified 2026-09-07
- SQL ServerRead-onlyMissing N prefix on NVARCHAR literals silently mangles Japanese/Korean text and emoji without any errorAn NVARCHAR literal missing its N prefix is implicitly converted with no error, losing non-ASCII characters. This summarizes detection methods and how to prevent recurrence.Last Verified 2026-08-16