[Bug]: pgjsonb get_fun raises SQL syntax error on PostgreSQL due to MySQL-style backtick quoting

What happened?

Description

salt/returners/pgjsonb.py:get_fun issues a query that uses MySQL-style backtick identifier quoting:

sql = """SELECT s.id,s.jid, s.full_ret
        FROM salt_returns s
        JOIN ( SELECT MAX(`jid`) as jid
            from salt_returns GROUP BY fun, id) max
        ON s.jid = max.jid
        WHERE s.fun = %s
        """

PostgreSQL — the only server pgjsonb talks to — rejects backticks at parse time:

ERROR:  syntax error at or near "`"
LINE 3:                 JOIN ( SELECT MAX(`jid`) as jid
                                          ^

The query is a near-verbatim copy-paste from salt/returners/mysql.py where the syntax is valid; the identifier quoting was overlooked when the file was adapted for PostgreSQL.

The bug is dormant in typical deployments. Stock master_job_cache: pgjsonb operation routes through get_load, get_jid, get_jids, get_minions, prep_jid, save_load, returner and event_return — none of those reach get_fun. The function surfaces only when an operator or an extension calls pgjsonb.get_fun explicitly, e.g. via a custom runner, or sets master_job_cache.get_fun to it from external tooling.

Setup

• on-prem machine
• classic packaging
• onedir packaging

Any deployment that uses master_job_cache: pgjsonb and either calls pgjsonb.get_fun directly or has tooling that does.

Steps to Reproduce the behavior

1. Configure master_job_cache: pgjsonb.
2. From a runner or REPL: salt-run salt.cmd pgjsonb.get_fun test.ping.
3. The call raises psycopg2.errors.SyntaxError: syntax error at or near "\"`.

Expected behavior

get_fun returns a {minion_id: full_ret} dict for the last execution of the given function across all minions.

Additional context

The accompanying PR drops the backticks (PostgreSQL does not require quoting around jid since it is not a reserved word) and adds a behavioural unit test that asserts the per-minion mapping is built correctly and guards against backticks creeping back into the SQL through future copy-paste from the mysql returner.

A separate, more interesting issue with this function — the MAX(jid) algorithm for "last execution" works only because the default Salt jid format (YYYYMMDDHHMMSSffffff) happens to be lexicographically sortable as a timestamp. Operators who override master_job_cache.gen_jid with a non-sortable id format (UUID, snowflake, random) get a silently-wrong answer here. That is a deeper bug and will be tracked as its own follow-up.

Type of salt install

Official deb

Major version

3006.x, 3007.x

What supported OS are you seeing the problem on? Can select multiple. (If bug appears on an unsupported OS, please open a GitHub Discussion instead)

debian-11, debian-12

salt --versions-report output

salt --versions-report
Salt Version:
          Salt: 3007.13

Python Version:
        Python: 3.10.19 (main, Feb  5 2026, 07:05:38) [GCC 11.2.0]

Dependency Versions:
          cffi: 2.0.0
      cherrypy: unknown
  cryptography: 42.0.5
      dateutil: 2.8.2
     docker-py: Not Installed
         gitdb: Not Installed
     gitpython: Not Installed
        Jinja2: 3.1.6
       libgit2: 1.9.1
  looseversion: 1.3.0
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.0.7
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     packaging: 24.0
     pycparser: 2.21
      pycrypto: Not Installed
  pycryptodome: 3.19.1
        pygit2: 1.18.2
  python-gnupg: 0.5.2
        PyYAML: 6.0.1
         PyZMQ: 25.1.2
        relenv: 0.22.3
         smmap: Not Installed
       timelib: 0.3.0
       Tornado: 6.5.4
           ZMQ: 4.3.4

Salt Extensions:
 saltext.vault: 1.5.0

Salt Package Information:
  Package Type: onedir

System Versions:
          dist: debian 12.13 bookworm
        locale: utf-8
       machine: x86_64
       release: 6.12.73+deb12-amd64
        system: Linux
       version: Debian GNU/Linux 12.13 bookworm

Start at salt/returners/pgjsonb.py:get_fun and reproduce the PostgreSQL syntax error through the pgjsonb.get_fun entry point. Verify the behavioral unit test covers the per-minion mapping and ensures the generated SQL contains no backticks; done means get_fun returns the expected mapping on PostgreSQL.