[BUG] Agent tries to query column `nspname` on `pg_index`

[sardaukar]

Agent Environment

We have the agent (v7.70.2) deployed on our Render production environment, and we have a persistent error message on our logs:

2025-09-22 14:50:23 UTC | CORE | INFO | (pkg/collector/worker/check_logger.go:40 in CheckStarted) | check:postgres | Running check...
2025-09-22 14:50:23 UTC | CORE | ERROR | (pkg/collector/python/datadog_agent.go:143 in LogMessage) | postgres:f26eb3c74874f76b | (postgres.py:273) | Unhandled exception while using database connection <REDACTED_DB_NAME>
Traceback (most recent call last):
  File "/opt/datadog-agent/embedded/lib/python3.12/site-packages/datadog_checks/postgres/postgres.py", line 258, in db
    yield self._db
  File "/opt/datadog-agent/embedded/lib/python3.12/site-packages/datadog_checks/postgres/postgres.py", line 241, in execute_query_raw
    cursor.execute(query)
  File "/opt/datadog-agent/embedded/lib/python3.12/site-packages/datadog_checks/postgres/cursor.py", line 28, in execute
    return super().execute(query, params, binary=binary, prepare=prepare)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/datadog-agent/embedded/lib/python3.12/site-packages/psycopg/cursor.py", line 97, in execute
    raise ex.with_traceback(None)
psycopg.errors.UndefinedColumn: column "nspname" does not exist
LINE 30: ) s WHERE (( 1=1 AND nspname = ANY(array['public']::text[]) ...
                              ^
HINT:  Perhaps you meant to reference the column "s.relname".
2025-09-22 14:50:23 UTC | CORE | ERROR | (pkg/collector/python/datadog_agent.go:143 in LogMessage) | - | (core.py:94) | Error querying pg_index: column "nspname" does not exist
LINE 30: ) s WHERE (( 1=1 AND nspname = ANY(array['public']::text[]) ...
                              ^
HINT:  Perhaps you meant to reference the column "s.relname".
2025-09-22 14:50:23 UTC | CORE | INFO | (pkg/collector/worker/check_logger.go:59 in CheckFinished) | check:postgres | Done running check

Which makes sense, since pg_index doesn't have an "nspname" column 🤷‍♂️

agent version output:

Agent 7.70.2 - Commit: 83bbd72567 - Serialization version: v5.0.161 - Go version: go1.24.6

our config:

init_config:
instances:
  - dbm: true
    host: REDACTED-a
    port: 5432
    username: datadog
    password: REDACTED
    dbname: REDACTED
    ssl: prefer
    dbstrict: true
    relations:
      - relation_regex: .*
        schemas:
          - public
        relkind:
          - r
          - i
    collect_schemas:
      enabled: true
    query_samples:
      explain_parameterized_queries: true
    tags:
      - 'env:prod'
      - 'service:REDACTED'
  - dbm: true
    host: REDACTED-b
    port: 5432
    username: datadog
    password: REDACTED
    dbname: REDACTED
    ssl: prefer
    dbstrict: true
    query_samples:
      explain_parameterized_queries: true
    tags:
      - 'env:prod'
      - 'service:REDACTED_replica'
  - dbm: true
    host: REDACTED-c
    port: 5432
    username: datadog
    password: REDACTED
    dbname: REDACTED
    ssl: prefer
    dbstrict: true
    query_samples:
      explain_parameterized_queries: true
    tags:
      - 'env:prod'
      - 'service:REDACTED_replica_two'
  - dbm: true
    host: REDACTED
    port: 5432
    username: datadog
    password: REDACTED
    dbname: REDACTED
    ssl: prefer
    dbstrict: true
    relations:
      - relation_regex: .*
        schemas:
          - public
        relkind:
          - r
          - i
    collect_schemas:
      enabled: true
    query_samples:
      explain_parameterized_queries: true
    tags:
      - 'env:prod'
      - 'service:REDACTED_oban'

We even changed it to have just

 relkind:
   - r

In an attempt to remove indices from being monitored, but we still see the same log message :(

Describe what happened:

• Persistent error message in the logs

Describe what you expected:

• No error message

Steps to reproduce the issue:

• Run datadog-agent on Render

Additional environment details (Operating System, Cloud provider, etc):

Render DB instances, using a variation of Render's own DD agent template. Three of the four instances are v15, one of them is v17 - but the error message seems to be from a DB running v15. Regardless, pg_index didn't have nspname in v15 either, so I don't think it's a v17 issue that I know it's not on your list of supported versions.

[sardaukar]

I even tried to change the regexes present from .* to "^(?!.*(pg_index)).*$" and same error message shown

[eric-weaver]

Thank you for raising this issue @sardaukar! I've reproduced this exception from the details you provided. We'll get a fix up for this.

Small note that in the future it would be best to report issues with the Postgres integration over in https://github.com/DataDog/integrations-core. Reporting over there will just help ensure the right groups are tagged automatically and the issue is seen quickly. Either way we appreciate the detailed report!