GPSS jobs fail with permission or ownership errors on transient external tables in gpss_external schema

Products

• VMware Tanzu Greenplum
• VMware Tanzu Greenplum / Gemfire

Issue/Introduction

When running GPSS ingestion jobs, job execution may fail with errors like below:

pq: permission denied for relation gpkafkaloadext_>

 

GPSS dynamically creates temporary external tables under the schema gpss_external during job execution. These tables are transient in nature, used as part of the data load pipeline.

In environments where multiple GPSS service accounts are used for ingestion, jobs may fail during retries or cleanup phases with permission or ownership errors.

This typically occurs when one service account attempts to drop or manage external tables created by another service account.

Cause

• Cross-account management of transient external tables is not supported in Greenplum or GPSS.

• Only the owner or a superuser can drop transient tables, regardless of shared roles or schema-level privileges.

• Schema roles can provide CREATE and USAGE access but cannot override ownership.

• This is expected behavior based on the Greenplum privilege model.

Resolution

Workaround:

Drop the transient external tables on failure. This will ensure that newly triggered GPSS jobs do not encounter permission conflicts.

 

Note:

R&D has acknowledged this limitation and plans to introduce an enhancement to support prefix customization for GPSS transient external tables. This improvement is targeted for inclusion in GPSS version 2.3.0, which is tentatively scheduled for release in January 2026.