"ERROR: cache lookup failed for function" when running gpbackup in Tanzu Greenplum

Products

• VMware Tanzu Greenplum

Issue/Introduction

When running gpbackup, it returns an error that states cache lookup failed and exited: 

ERROR: cache lookup failed for function 63142680 (ruleutils.c:1472) (SQLSTATE XX000)

This error occurs when the backup operation attempted to back up a constraint, function, index, rule, or view that was dropped during the backup.

Environment

Product Version: 5.21

Resolution

This issue is fixed in Tanzu Greenplum v5.27.0 or later, and in Tanzu Greenplum v6.7.1 and later.

To resolve this issue, you need to update gpbackup to v1.18 or later. In these versions, the information is logged and the backup continues.