# evm.execution_observation_pairs

One row per logical observation key with pre and terminal values side by side. changed compares exact raw bytes; numeric projections are populated only for complete integer pairs.

Canonical HTML: <https://determica.com/docs/tables/evm-execution-observation-pairs>

- Kind: View
- Layer: execution_read_model
- Category: Simulation
- Tags: Program, Execution, Public, View

## Contract and lifecycle

**Grain:** One pre/terminal comparison per (execution_id, observation_key).

**Lifecycle:** run publishes this immutable row set atomically with its owning run. Statement failure or caller rollback publishes no durable prefix; direct DML is unsupported because it can corrupt the documented invariants.

**Status and NULLs:** Interpret nullable payloads only through their owning status fields. Defensive poisoned and engine_error outcomes mean the engine refused to claim a trustworthy normal result; broad view nullability also covers owner alternatives and left-joined evidence.

### Join guidance

- Join evm.executions on execution_id for candidate and run context.
- Use attempt_id to deduplicate physical facts expanded across contextual owners.
- For program owners use step_index; for observation-call owners use observation_index and observation_key.

### Effect semantics

- Access flags describe attempted EVM access, not committed state change.
- Effect facts retain attempted evidence and final committed, reverted, discarded, or poisoned disposition.
- execution_state_deltas contains committed checkpoint transitions only; observation-call effects are excluded from execution_effect_summary.

## Columns

### Identity and ownership

Contextual keys and reusable identities that establish row ownership.

- `execution_id` (UUID; nullable) — Contextual execution association identity; do not use it as reusable artifact identity.
- `observation_key` (VARCHAR; nullable) — Byte-exact caller observation identity for an observation_call owner; otherwise NULL.

### Chain context

Pinned chain, block, profile, and revision context.

- `chain_id` (UBIGINT; nullable) — EVM chain identifier frozen for the owning execution.
- `chain_profile` (VARCHAR; nullable) — Named chain-rules profile frozen for the owning execution.

### Payload and evidence

Operation-specific inputs, outputs, and authenticated evidence.

- `read_kind` (VARCHAR; nullable) — Canonical READ family used by the logical observation.
- `subject_address` (ADDRESS; nullable) — Documented subject_address value for this public execution-data row.
- `asset_kind` (VARCHAR; nullable) — Documented asset_kind value for this public execution-data row.
- `asset_address` (ADDRESS; nullable) — Documented asset_address value for this public execution-data row.
- `pre_value` (EVM_VALUE; nullable) — Typed pre-checkpoint value fields; NULL unless the pre point succeeded.
- `terminal_value` (EVM_VALUE; nullable) — Typed terminal-checkpoint value fields; NULL unless the terminal point succeeded.
- `changed` (BOOLEAN; nullable) — Exact raw-value inequality; NULL unless both endpoint points succeeded.
- `delta` (INT512; nullable) — Terminal minus pre as INT512 for complete uint or int EVM_VALUE pairs.
- `delta_direction` (VARCHAR; nullable) — increase, decrease, or unchanged for a complete integer pair; otherwise NULL.
- `delta_magnitude` (UINT256; nullable) — Absolute endpoint difference as UINT256 for a complete integer pair; otherwise NULL.

### Status and disposition

Outcome vocabulary and NULL-controlling disposition fields.

- `pair_status` (VARCHAR; nullable) — complete when both endpoints succeeded, partial when one succeeded, otherwise failed.
- `pre_status` (VARCHAR; nullable) — Status of the pre checkpoint point; NULL when no pre point was scheduled.
- `pre_error_code` (VARCHAR; nullable) — Stable pre-point failure code; NULL without a pre failure.
- `terminal_status` (VARCHAR; nullable) — Status of the terminal checkpoint point; NULL when no terminal point was scheduled.
- `terminal_error_code` (VARCHAR; nullable) — Stable terminal-point failure code; NULL without a terminal failure.

### Commitments

Hashes and roots authenticating specifications, facts, state, or results.

- `read_root` (BYTES32; nullable) — Canonical identity of the READ shared by every point under the logical key.

## Linked joins

- `execution_id` → [evm.executions](/docs/tables/evm-executions.md) (`execution_id`) — Contextual execution that exposes this public row.

## Related public objects

- [evm.executions](/docs/tables/evm-executions.md) — upstream

## Verified queries

### Confirm fixture coverage

Confirm that this object has rows owned by the stable seven-candidate public fixture.

```sql
SELECT 'evm.execution_observation_pairs'::VARCHAR AS object_name, CASE WHEN count(*) > 0 THEN 'PASS' ELSE 'FAIL' END::VARCHAR AS status FROM evm."execution_observation_pairs" o JOIN evm.executions e USING (execution_id) WHERE e.candidate_key IN ('complete-effects', 'later-revert', 'ordered-logs', 'create', 'selfdestruct', 'blockhash', 'transient-access');
```

### Check candidate ownership

Diagnose whether this object remains linked to at least one stable fixture candidate through public keys.

```sql
SELECT 'evm.execution_observation_pairs'::VARCHAR AS object_name, CASE WHEN count(DISTINCT e.candidate_key) > 0 THEN 'PASS' ELSE 'FAIL' END::VARCHAR AS status FROM evm."execution_observation_pairs" o JOIN evm.executions e USING (execution_id) WHERE e.candidate_key IN ('complete-effects', 'later-revert', 'ordered-logs', 'create', 'selfdestruct', 'blockhash', 'transient-access');
```