How to fix Error 2803 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: Error 2803 – Cachestore Flush Event (SQL Server 2025)

Why This Error Happens

This informational message occurs when SQL Server 2025 clears the plan cache (or a specific cachestore such as CACHESTORE_OBJCP or CACHESTORE_SQLCP) in response to database maintenance operations like ALTER DATABASE, sp_configure reconfiguration, or memory pressure events. It is typically triggered by DDL operations, changes to server-level configuration options, or automated maintenance plans that force SQL Server to invalidate cached execution plans for consistency. While not a critical failure, frequent occurrences can indicate excessive configuration changes or maintenance jobs running more often than necessary, leading to degraded query performance due to repeated plan recompilation.

Step-by-Step Resolution Guide

Step 1: Identify the Source of the Reconfigure Operations

  • Open SQL Server Management Studio (SSMS) and query the error log using EXEC sp_readerrorlog 0, 1, 'cachestore flush';
  • Cross-reference the timestamp of the flush event with your SQL Agent Job History (msdb.dbo.sysjobhistory) to identify recent maintenance plans.
  • Check for recent ALTER DATABASE [DBName] SET ... commands or sp_configure changes run by DBAs or third-party monitoring tools.

Step 2: Audit and Consolidate Database Maintenance Plans

  • Navigate to SQL Server Agent > Jobs in SSMS and review the schedule of Index Rebuild, Update Statistics, or Integrity Check jobs.
  • Consolidate overlapping maintenance tasks; running ALTER DATABASE or index operations too frequently (e.g., every 15 minutes) will repeatedly flush the cache.
  • Adjust the schedule to run intensive maintenance during off-peak hours only, reducing the job frequency to once every 24 hours if business logic allows.

Step 3: Review Server Configuration Stability

  • Open a query window and run SELECT * FROM sys.configurations WHERE value_in_use <> value; to check for pending configuration changes that require a cache flush.
  • Ensure third-party monitoring tools (like Dynatrace or SolarWinds) are not issuing repeated sp_configure 'show advanced options' commands, as toggling this setting forces a plan cache flush.
  • Apply configuration changes using RECONFIGURE only once, consolidating multiple settings changes into a single batch script to avoid multiple flush events.

Step 4: Optimize Plan Cache Memory Pressure

  • Navigate to the Windows Server 2025 Performance Monitor (PerfMon) and add the counter SQLServer:Plan Cache - Cache Hit Ratio.
  • If the hit ratio is low immediately following the error, verify the max server memory setting in SSMS under Server Properties > Memory to ensure the OS is not forcing SQL Server to trim its cache due to insufficient system RAM.
  • Increase available memory for the Windows Server 2025 instance or adjust the min server memory to stabilize the cache footprint.

Alternative or Verification Steps

  • Verification: Run DBCC MEMORYSTATUS and check the Procedure Cache section to confirm the cache size remains stable and is no longer dropping to zero immediately after your scheduled maintenance windows.
  • Alternative: If flushes persist due to necessary business logic (e.g., mandatory schema changes), consider using Query Store to retain performance history independently of the plan cache, ensuring that the flush does not result in a total loss of execution plan analytics.