Error
Error Code:
HV009
PostgreSQL Error HV009: FDW Null Pointer Dereference
Description
This error indicates that a Foreign Data Wrapper (FDW) encountered an invalid memory access, specifically attempting to use a null pointer. It typically occurs when the FDW's internal logic expects a valid data reference but receives `NULL`, often due to misconfiguration, unexpected external system behavior, or a bug within the FDW extension itself.
Error Message
fdw invalid use of null pointer
Known Causes
3 known causesUnavailable Foreign Server
The external data source that the FDW connects to is unreachable, offline, or returns unexpected connection errors, causing the FDW to fail during initialization or data retrieval.
FDW Extension Bug
A defect within the specific Foreign Data Wrapper extension itself leads to improper handling of certain data conditions, query types, or edge cases, resulting in a null pointer access.
Data Type Mismatch
The data types defined in the foreign table do not align with the actual data types on the foreign server, causing the FDW to misinterpret data and encounter null references.
Solutions
Coming SoonDetailed step-by-step solutions for this error are being prepared. In the meantime, try these general troubleshooting tips:
General Troubleshooting Tips
- Check the error message carefully for specific details
- Review recent changes that might have caused the error
- Search for the exact error code in the official documentation
- Check log files for additional context
- Try restarting the application or service