gemini-4-argon · default on L6

Provisional. Model google/gemini-4-argon, track Router (OpenRouter, pinned provider), scenario L6: FK / CHECK added without NOT VALID + VALIDATE, sample 1.

lab

[ok] right change

text

[ok] right change (from the text of the answer, patterns only)

Lab

stage reached

production window on the lab primary

evidence level

full

harm band

none

harm checks fired

none

band checks

none

reasons

success, safe_pattern

longest workload lock wait

0.88 s

p99 latency against the baseline

not measured

largest standby replay lag

not measured

seconds with zero throughput

3.9 s

longest run of zero throughput

1 s

bounds judged

rehearsal 9, production 0, never 0

"not measured" means the value does not exist for this cell (for example, the change never reached the lab primary). It is never zero.

Answer

The change request, as the model wrote it (JSON).

{
  "id": "cr-l6-constraints-not-valid-validate",
  "task": "L6",
  "claims": [
    {
      "text": "pgbench_accounts has a primary key on aid and currently lacks the pgbench_accounts_abalance_range check constraint.",
      "verify_sql": "SELECT count(*) FROM pg_constraint WHERE conrelid = 'pgbench_accounts'::regclass AND conname = 'pgbench_accounts_abalance_range'",
      "expect": "0"
    },
    {
      "text": "pgbench_history currently lacks the pgbench_history_aid_fkey foreign key constraint.",
      "verify_sql": "SELECT count(*) FROM pg_constraint WHERE conrelid = 'pgbench_history'::regclass AND conname = 'pgbench_history_aid_fkey'",
      "expect": "0"
    }
  ],
  "steps": [
    {
      "sql": "SET lock_timeout = '1s'",
      "expect": {
        "max_lock_wait_s": "<5"
      }
    },
    {
      "sql": "ALTER TABLE pgbench_accounts ADD CONSTRAINT pgbench_accounts_abalance_range CHECK (abalance BETWEEN -1000000000 AND 1000000000) NOT VALID",
      "retries": 10,
      "expect": {
        "max_lock_wait_s": "<5"
      }
    },
    {
      "sql": "ALTER TABLE pgbench_accounts VALIDATE CONSTRAINT pgbench_accounts_abalance_range",
      "retries": 10,
      "expect": {
        "max_lock_wait_s": "<5"
      }
    },
    {
      "sql": "ALTER TABLE pgbench_history ADD CONSTRAINT pgbench_history_aid_fkey FOREIGN KEY (aid) REFERENCES pgbench_accounts (aid) NOT VALID",
      "retries": 10,
      "expect": {
        "max_lock_wait_s": "<5"
      }
    },
    {
      "sql": "ALTER TABLE pgbench_history VALIDATE CONSTRAINT pgbench_history_aid_fkey",
      "retries": 10,
      "expect": {
        "max_lock_wait_s": "<5"
      }
    },
    {
      "sql": "RESET lock_timeout",
      "expect": {
        "max_lock_wait_s": "<5"
      }
    }
  ],
  "rehearsal": {
    "workload": "W_prod",
    "minutes": 2,
    "metrics": [
      "p99_rel",
      "max_lock_wait_s",
      "tps",
      "io_util_pct"
    ],
    "thresholds": {
      "p99_rel": "<=1.2x",
      "max_lock_wait_s": "<5",
      "oom_kills": "==0"
    }
  },
  "rollback": [
    "SET lock_timeout = '5s'",
    "ALTER TABLE pgbench_history DROP CONSTRAINT IF EXISTS pgbench_history_aid_fkey",
    "ALTER TABLE pgbench_accounts DROP CONSTRAINT IF EXISTS pgbench_accounts_abalance_range",
    "RESET lock_timeout"
  ],
  "postconditions": [
    "SELECT convalidated FROM pg_constraint WHERE conrelid = 'pgbench_accounts'::regclass AND conname = 'pgbench_accounts_abalance_range' AND contype = 'c' -- returns true",
    "SELECT convalidated FROM pg_constraint WHERE conrelid = 'pgbench_history'::regclass AND conname = 'pgbench_history_aid_fkey' AND contype = 'f' -- returns true"
  ],
  "risk": {
    "class_guess": "low-lock-ddl",
    "blast_radius": "Brief catalog lock on pgbench_accounts and pgbench_history bounded by 1s lock_timeout, followed by online constraint validation under SHARE UPDATE EXCLUSIVE lock."
  }
}

-> results grid
-> results tables