How to fix Error 4958 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: Error 4958 – ROWGUIDCOL Property Mismatch in ALTER TABLE SWITCH

Why This Error Happens

This error occurs because SQL Server requires the source and target tables in a partition switch operation to have structurally identical schemas, including the ROWGUIDCOL property on matching columns. When one table has a uniqueidentifier column flagged with ROWGUIDCOL and the corresponding column in the other table does not, SQL Server blocks the switch to prevent metadata inconsistency. This typically happens when tables were created at different times, through different scripts, or when a column was altered after the table was initially provisioned.

Step-by-Step Resolution Guide

Step 1: Identify the Mismatched Column

  • Run the following query against both the source and target tables to inspect the ROWGUIDCOL flag:
  • SELECT name, is_rowguidcol FROM sys.columns WHERE object_id = OBJECT_ID('YourSchema.YourTable');
  • Compare the output between both tables to confirm which column has is_rowguidcol = 1 on one side but 0 on the other.
  • Note the exact column name returned in the Error 4958 message (the %.*ls placeholders will show it in the actual error output).

Step 2: Correct the ROWGUIDCOL Property

  • Since you cannot directly toggle ROWGUIDCOL via a simple ALTER COLUMN, you must drop and re-add the property using a workaround.
  • Create a new column with the correct property, migrate data, then drop the old column:
  • ALTER TABLE YourSchema.YourTable ADD NewGuidCol uniqueidentifier ROWGUIDCOL NOT NULL DEFAULT NEWID();
  • UPDATE YourSchema.YourTable SET NewGuidCol = OldGuidCol;
  • Alternatively, if only one table incorrectly has ROWGUIDCOL set, remove it by recreating the column without the property instead.
  • Ensure both tables end up with matching is_rowguidcol values before attempting the switch again.

Step 3: Validate Table and Index Schema Alignment

  • Open SQL Server Management Studio (SSMS) 21 or Azure Data Studio connected to your SQL Server 2025 instance.
  • Right-click both tables and select “Script Table as > CREATE To > New Query Editor Window” to visually diff the schemas side-by-side.
  • Confirm that constraints, collation, nullability, and identity properties also match, as these commonly accompany ROWGUIDCOL mismatches.
  • Check sys.indexes and sys.partitions to ensure partition schemes and filegroups align between source and target tables.

Step 4: Rerun the ALTER TABLE SWITCH Command

  • Execute the switch statement again in a test environment first:
  • ALTER TABLE YourSchema.SourceTable SWITCH TO YourSchema.TargetTable PARTITION n;
  • Monitor the Windows Server 2025 Event Viewer (Applications and Services Logs > Microsoft > SQL Server) for any residual Error 4958 entries.
  • If the error persists, restart the SQL Server service via services.msc or net stop MSSQLSERVER && net start MSSQLSERVER to clear any cached metadata.

Alternative or Verification Steps

  • Verify success by re-running the sys.columns query from Step 1 on both tables and confirming is_rowguidcol values are now identical (both 0 or both 1).
  • If recreating the column is not feasible due to downstream dependencies (triggers, replication, or foreign keys), consider using SELECT INTO to stage a new target table with correct schema properties, then repoint applications to the new table instead of switching partitions.