BUG #19489: Function Name Conflict Between TimescaleDB and pg_stat_monitor Affecting Extension Upgrade

The following bug has been logged on the website:

Bug reference: 19489
Logged by: Siddharth Gupta
Email address: siddharth(dot)gupta(at)nutanix(dot)com
PostgreSQL version: 18.4
Operating system: All
Description:

Hi Team,

We observed a potential function name conflict between TimescaleDB and
pg_stat_monitor during extension compatibility and upgrade validation.

Details observed:

PostgreSQL Version: All versions
TimescaleDB Version: all versions
pg_stat_monitor Version: All versions

The common function/object identified is:

Function Name: histogram

Issue observed:
When both extensions are present in the same database, the shared function
name appears to create a conflict during extension operations.

Specifically, this issue prevents pg_stat_monitor from successfully
completing the ALTER EXTENSION UPDATE operation. The upgrade fails due to
the conflicting histogram function definition/object resolution between the
two extensions.

Current observations:

Individual installation and upgrade of each extension works as expected.
The issue is reproducible only when both TimescaleDB and pg_stat_monitor
coexist in the same cluster/database.
The failure is observed during pg_stat_monitor extension upgrade execution.

Reproducible Steps:

Install PostgreSQL
Create extension TimescaleDB
Create extension pg_stat_monitor(older version)

Execute:

ALTER EXTENSION pg_stat_monitor UPDATE;
Observe the failure related to the histogram function/object conflict.