The spDeleteUpdate stored procedure runs slowly

When the spDeleteUpdate stored procedure runs, it may take tens of seconds for it to delete a single update. When you use spDeleteUpdate to delete hundreds or thousands of updates during Windows Server Update Services (WSUS) maintenance, it may take days to finish.

Cause

The slow performance occurs because a primary key isn't set on a temporary table that's created by spDeleteUpdate.

Resolution

To fix the issue, run the following SQL script against the WSUS database (SUSDB) on every affected WSUS server. This script sets a primary key on the @revisionList temporary table.

USE [SUSDB]
GO

/****** Object:  StoredProcedure [dbo].[spDeleteUpdate]    Script Date: 11/2/2020 8:55:02 AM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

 
ALTER PROCEDURE [dbo].[spDeleteUpdate]
    @localUpdateID int
AS
SET NOCOUNT ON
BEGIN TRANSACTION
SAVE TRANSACTION DeleteUpdate
DECLARE @retcode INT
DECLARE @revisionID INT
DECLARE @revisionList TABLE(RevisionID INT PRIMARY KEY)
INSERT INTO @revisionList (RevisionID)
    SELECT r.RevisionID FROM dbo.tbRevision r
        WHERE r.LocalUpdateID = @localUpdateID
IF EXISTS (SELECT b.RevisionID FROM dbo.tbBundleDependency b WHERE b.BundledRevisionID IN (SELECT RevisionID FROM @revisionList))
   OR EXISTS (SELECT p.RevisionID FROM dbo.tbPrerequisiteDependency p WHERE p.PrerequisiteRevisionID IN (SELECT RevisionID FROM @revisionList))
BEGIN
    RAISERROR('spDeleteUpdate got error: cannot delete update as it is still referenced by other update(s)', 16, -1)
    ROLLBACK TRANSACTION DeleteUpdate
    COMMIT TRANSACTION
    RETURN(1)
END
INSERT INTO @revisionList (RevisionID)
    SELECT DISTINCT b.BundledRevisionID FROM dbo.tbBundleDependency b
        INNER JOIN dbo.tbRevision r ON r.RevisionID = b.RevisionID
        INNER JOIN dbo.tbProperty p ON p.RevisionID = b.BundledRevisionID
        WHERE r.LocalUpdateID = @localUpdateID
            AND p.ExplicitlyDeployable = 0
IF EXISTS (SELECT IsLocallyPublished FROM dbo.tbUpdate WHERE LocalUpdateID = @localUpdateID AND IsLocallyPublished = 1)
BEGIN
    INSERT INTO @revisionList (RevisionID)
        SELECT DISTINCT pd.PrerequisiteRevisionID FROM dbo.tbPrerequisiteDependency pd
            INNER JOIN dbo.tbUpdate u ON pd.PrerequisiteLocalUpdateID = u.LocalUpdateID
            INNER JOIN dbo.tbProperty p ON pd.PrerequisiteRevisionID = p.RevisionID
            WHERE u.IsLocallyPublished = 1 AND p.UpdateType = 'Category'
END
DECLARE #cur CURSOR LOCAL FAST_FORWARD FOR
    SELECT t.RevisionID FROM @revisionList t ORDER BY t.RevisionID DESC
OPEN #cur
FETCH #cur INTO @revisionID
WHILE (@@ERROR=0 AND @@FETCH_STATUS=0)
BEGIN
    IF EXISTS (SELECT b.RevisionID FROM dbo.tbBundleDependency b WHERE b.BundledRevisionID = @revisionID
                   AND b.RevisionID NOT IN (SELECT RevisionID FROM @revisionList))
       OR EXISTS (SELECT p.RevisionID FROM dbo.tbPrerequisiteDependency p WHERE p.PrerequisiteRevisionID = @revisionID
                      AND p.RevisionID NOT IN (SELECT RevisionID FROM @revisionList))
    BEGIN
        DELETE FROM @revisionList WHERE RevisionID = @revisionID
        IF (@@ERROR <> 0)
        BEGIN
            RAISERROR('Deleting disqualified revision from temp table failed', 16, -1)
            GOTO Error
        END
    END
    FETCH NEXT FROM #cur INTO @revisionID
END
IF (@@ERROR <> 0)
BEGIN
    RAISERROR('Fetching a cursor to value a revision', 16, -1)
    GOTO Error
END
CLOSE #cur
DEALLOCATE #cur
DECLARE #cur CURSOR LOCAL FAST_FORWARD FOR
    SELECT t.RevisionID FROM @revisionList t ORDER BY t.RevisionID DESC
OPEN #cur
FETCH #cur INTO @revisionID
WHILE (@@ERROR=0 AND @@FETCH_STATUS=0)
BEGIN
    EXEC @retcode = dbo.spDeleteRevision @revisionID
    IF @@ERROR <> 0 OR @retcode <> 0
    BEGIN
        RAISERROR('spDeleteUpdate got error from spDeleteRevision', 16, -1)
        GOTO Error
    END
    FETCH NEXT FROM #cur INTO @revisionID
END
IF (@@ERROR <> 0)
BEGIN
    RAISERROR('Fetching a cursor to delete a revision', 16, -1)
    GOTO Error
END
CLOSE #cur
DEALLOCATE #cur
COMMIT TRANSACTION
RETURN(0)
Error:
    CLOSE #cur
    DEALLOCATE #cur
    IF (@@TRANCOUNT > 0)
    BEGIN
        ROLLBACK TRANSACTION DeleteUpdate
        COMMIT TRANSACTION
    END
    RETURN(1)
GO