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SQL Server 2019 CU28 SQL Server 2019 CU28 Cumulative update

KB5039747

KB5039747: Cumulative update for SQL Server 2019, CU branch, August 2024. SESSION_CONTEXT errors in parallel plans; backup and patching issues

In short

CU28 adds 13 fixes, but queries using SESSION_CONTEXT in parallel plans might return incorrect results or trigger access violations. Two other listed issues are fixed in CU29.

Does it affect you? Applies to: SQL Server 2019 instances. The package applies to all supported languages and updates only the SQL Server components installed on the instance.

Build
15.0.4385.2
Servicing branch
CU
Restart
Required

For servers on the CU branch: they install cumulative updates, which also bring fixes beyond security. Servers on the GDR branch (security fixes only) get a separate update. Which branch am I on?

What changes

Fixes 10 changes

Backup Restore

  • A VSS restore no longer encounters an error when the SQL Server instance previously had deleted databases.1
    Fixes a Volume Shadow Copy Service (VSS) restore error calling GetVolumePathName on a path that cannot be found.

Extensibility

  • The SQL Server Launchpad service can shut down properly when certain errors occur during startup.2

Metadata

3 items
  • Fetching the next value for sequence objects no longer encounters the listed latch time-out caused by self-deadlock during lock escalation.3
  • The Database Engine can obtain lock resources again when the listed error 1204 occurs.4
    Fixes error 1204 caused by an unintentionally disabled lock escalation regression introduced in CU26.
  • Fetching the next value for sequence objects no longer encounters the listed latch time-out caused by self-deadlock during lock escalation.5

PolyBase

  • PolyBase no longer throws the listed startup error when the SQL Server instance listens on multiple TCP ports.6
    Fixes System.ArgumentException: Unable to parse port at service startup for instances configured to listen on multiple TCP ports.

Query Optimizer

  • Forcing a query plan in Query Store no longer triggers the listed non-yielding scheduler dump issue.7
    Fixes a non-yielding scheduler dump issue encountered when forcing a query plan in Query Store (QDS).

Replication

2 items
  • Transactional replication no longer stops with error 18752 in the described high-workload availability-group scenario after a failover.8
    Fixes error 18752 when a heavy workload is used with availability groups and a failover occurs.
  • The listed error 21890 no longer occurs when sp_validate_redirected_publisher is run with a case-sensitive collation.9
    Fixes error 21890 encountered when running sp_validate_redirected_publisher with a case-sensitive collation.

SQL OS

  • Running a stored procedure on a remote SQL Server instance through a linked server no longer encounters the listed out-of-memory issue.10

Improvements 3 changes

Analysis Services

  • Intel Threading Building Blocks assemblies are digitally signed with a Microsoft certificate.11
    Digitally signs the Intel Threading Building Blocks (Intel TBB) assemblies by using a Microsoft certificate.

Command Line Tools

For: Administrators using SQL Server Linux container images

  • SQL Server 2019 container images use the new mssql-tools18 package and tools directory. The previous tools directory is phased out.12
    Starting with SQL Server 2019 CU28, container images include mssql-tools18; the Microsoft ODBC 18 tools are in /opt/mssql-tools18/bin, replacing the phased-out /opt/mssql-tools/bin directory.

SQL OS

  • A high-I/O-latency warning is logged less often, reducing excessive entries in the SQL Server error log.13
    Increases the threshold for the Long asynchronous API Call log message when high I/O latencies are detected in Bufferpool Lazy Writer (ntdll!ZwWriteFile).

Known issues

  1. Open Affects: Everyone

    Incorrect behavior of SESSION_CONTEXT in parallel plans

    Queries using SESSION_CONTEXT might return incorrect results or trigger access violation dumps when run in parallel query plans, particularly if the session is reset for reuse.14

    Workaround status No workaround yet

    Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.

  2. Open Affects: Organizations and IT administrators

    Issue two: SQL Server VSS Writer might fail to perform a backup because no database is available to freeze

    Backup tools might fail to achieve application consistency when the SQL Server VSS Writer has no database available to freeze. Rolling back to SQL Server 2019 CU27 is the stated workaround; SQL Server 2019 CU29 fixes this issue.15

    How to apply the workaround Workaround

    Roll back to SQL Server 2019 CU27 and perform the snapshot backup.15

    Step-by-step workaround instructions
    2 steps
    Show steps Hide steps
    Step-by-step procedure
    1. Roll back the package to SQL Server 2019 CU27.
    2. Perform the snapshot backup.
  3. Resolved Affects: Organizations and IT administrators Resolved by KB5037331

    Issue three: Patching error for secondary replicas in an availability group with databases enabled replication or CDC

    When Setup patches an availability group with a database enabled for replication or CDC, it might report an initial failure in single-user mode. Patching completes after SQL Server starts again outside single-user mode, with no user action required; SQL Server 2019 CU29 fixes this issue.16

    How to apply the workaround SQL Trace Flag

    Before patching, enable Trace Flag 12347 and remove it after patching, or remove the replication- or CDC-enabled database from the availability group or remove replication or CDC from that database.16

    Step-by-step workaround instructions
    2 steps
    Show steps Hide steps
    Step-by-step procedure
    1. Before running the patch, enable Trace Flag 12347, or use one of the listed alternatives: drop the replication- or CDC-enabled database from the availability group, or remove replication or CDC from the database.
    2. Remove Trace Flag 12347 after patching if you enabled it.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2024-08-01
Classification
Updates
Type
Cumulative update
Servicing branch
CU
Restart
Required
Replaces
KB5037331, KB5035123, KB5033688
Replaced by
KB5042749
VersionBuildChannel
2019 15.0.4385.2 General availability

Security

No vulnerabilities are listed for this update.

Downloads (Microsoft Update Catalog)

Package 2019
880.2 MB
sqlserver2019-kb5039747-x64.exe Main update · KB5039747 SHA-1: 1cad9480…95b095

Sources

Updated
Cited passages from Microsoft's official notes (16)
  1. 1. Fixes the following error that you encounter during a Volume Shadow Copy Service (VSS) restore on a SQL Server instance that has previously deleted databases: Volume Shadow Copy Service error: Unexpected error calling routine GetVolumePathName is fail on the path <PathName> ... The system cannot find the file specified. support.microsoft.com
  2. 2. Fixes an issue in which the SQL Server Launchpad service can't shut down properly when certain errors occur during startup. support.microsoft.com
  3. 3. Fixes a latch time-out issue that you encounter when fetching the next value for sequence objects, which is due to self-deadlock during lock escalation. support.microsoft.com
  4. 4. Fixes the following error 1204 due to unintentionally disabled lock escalation regression introduced in CU26: SQL Server Database Engine cannot obtain a LOCK resource at this time. support.microsoft.com
  5. 5. Fixes a latch time-out issue that you encounter when fetching the next value for sequence objects, which is due to self-deadlock during lock escalation. support.microsoft.com
  6. 6. Fixes an issue in which PolyBase throws the following error at service startup if the SQL Server instance is configured to listen on multiple TCP ports: System.ArgumentException: Unable to parse port support.microsoft.com
  7. 7. Fixes a non-yielding scheduler dump issue that you might encounter when forcing a query plan in the Query Store (QDS). support.microsoft.com
  8. 8. Fixes an issue in which error 18752 occurs and transactional replication stops working when you use a heavy workload in combination with availability groups and after a failover occurs. support.microsoft.com
  9. 9. Fixes the following error 21890 that you encounter when you use the case-sensitive collation and run sp_validate_redirected_publisher support.microsoft.com
  10. 10. Fixes an out of memory issue that you encounter when running a stored procedure on a remote SQL Server instance by using a linked server. support.microsoft.com
  11. 11. Digitally signs the Intel Threading Building Blocks (Intel TBB) assemblies by using a Microsoft certificate. support.microsoft.com
  12. 12. Starting with SQL Server 2019 (15.x) CU28, container images include the new mssql-tools18 package. The previous directory /opt/mssql-tools/bin is phased out. The new directory for Microsoft ODBC 18 tools is /opt/mssql-tools18/bin support.microsoft.com
  13. 13. Increases the threshold of the following log message when high I/O latencies are detected in Bufferpool Lazy Writer (ntdll!ZwWriteFile system call) due to a performance issue in the underlying storage support.microsoft.com
  14. 14. Queries that use the built-in SESSION_CONTEXT function might return incorrect results or trigger access violation (AV) dump files when run in parallel query plans. support.microsoft.com
  15. 15. The current solution is to roll back to SQL Server 2019 CU27 and perform the snapshot backup. support.microsoft.com
  16. 16. This issue is fixed in SQL Server 2019 CU29. support.microsoft.com
Checked automatically: 8 of 8 checks passed, 16 quoted passages · compared with Microsoft's page on Oct 20, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: passed

A second AI read the text against the sources: correctness 5/5, clarity 4/5, completeness 5/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake