> ## Documentation Index > Fetch the complete documentation index at: https://docs.sqlbuild.com/llms.txt > Use this file to discover all available pages before exploring further. # Configuration > MODEL() header fields and SQL-validation controls. ## Common fields | Field | Description | | ---------------- | ----------------------------------------------------------------------------------------- | | `materialized` | `view`, `table`, `incremental`, `snapshot`, or a custom materialization name | | `tags` | Tags used by selectors | | `description` | Human-readable model description | | `columns` | Model-local column declarations or inherited-column audit augmentation | | `model_schema` | Reusable column schema name | | `audits` | Model-level audit instances | | `enums` | Model-local enum declarations; names must begin with `_` | | `constants` | Model-local scalar constants; names must begin with `_` | | `schema` | Destination warehouse schema override | | `database` | Destination database override | | `alias` | Destination relation-name override | | `pre_hooks` | SQL or Python hooks before materialization | | `post_hooks` | SQL or Python hooks after materialization | | `enabled` | Set to `false` to disable the model | | `contract` | `none` for an open statically checked declaration, or `enforced` for an exact declaration | | `sql_validation` | Per-model SQL-validation override | ## SQL validation SQL validation has two hard gates and one effective setting: 1. `settings.sql_analysis` must be enabled. 2. `--no-sql-validation` must not be present. 3. `MODEL (sql_validation true|false)` overrides `settings.sql_validation` for that model. If omitted, the project setting is used. The model override can re-enable validation when the project-level `settings.sql_validation` value is false, but it cannot bypass disabled SQL analysis or the CLI kill switch. ## Table fields | Field | Description | | ----------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `run_despite_unchanged` | Table-only change-aware policy. `always` rebuilds whenever selected. A duration such as `30d`, `12h`, or `90m` rebuilds while the newest timestamp-based upstream source observation is within that age; it is not a periodic schedule. | Table promotion mode is a project setting rather than a `MODEL()` field. Staged promotion is the default. Direct promotion is incompatible with model type enforcement and exact contracts; see [Materializations](/concepts/models/materializations#table). ## Incremental fields | Field | Description | | ------------------------- | ----------------------------------------------------------------------------------------------------------- | | `incremental_strategy` | `append`, `delete_insert`, or `merge` | | `cursor` | Output column used to track incremental position | | `cursor_type` | `timestamp` or `integer` | | `cursor_grain` | Timestamp grain such as `second`, `hour`, or `day` | | `cursor_start` | Lower cursor bound | | `cursor_inputs` | Upstream names mapped to cursor columns | | `unique_key` | Merge or delete/insert matching columns | | `incremental_mode` | Set to `microbatch` for batched execution | | `batch_size` | Timestamp duration string such as `1d` or `1h`; use a numeric string such as `"1000"` for an integer cursor | | `lookback` | Backward replay extension | | `append_cursor_inclusive` | Include (`true`, default) or exclude (`false`) the current append-cursor boundary | | `merge_exclude_columns` | Columns left unchanged by matched-row merge updates | | `allow_full_refresh` | Allow or deny explicit full refresh for this incremental model | | `on_schema_change` | `append_new_columns`, `sync_all_columns`, `ignore`, or `fail` | | `replay_on_change` | `forward`, `full`, or `bounded-` | See [Incremental](/concepts/incremental) for full semantics. Current compatibility behavior treats an unrecognized `on_schema_change` value as the default `append_new_columns` policy and an unrecognized `replay_on_change` value as `forward`. Use the documented values exactly; future validation may reject unknown values instead of applying these fallbacks. ## Snapshot fields | Field | Description | | ------------------------- | ----------------------------------------------------- | | `unique_key` | Columns identifying one logical record | | `snapshot_strategy` | `timestamp` or `check` | | `updated_at` | Source update timestamp for the timestamp strategy | | `check_columns` | Columns compared by the check strategy, or `[*]` | | `observed_at` | Observation timestamp for historical inputs | | `historical_input` | `snapshot` or `changes` | | `initial_valid_from` | Initial validity policy for first-seen rows | | `invalidate_hard_deletes` | Close records that disappear from current-state input | | `valid_from_column` | Override the generated valid-from column name | | `valid_to_column` | Override the generated valid-to column name | | `snapshot_full_refresh` | Snapshot full-refresh safety policy | | `snapshot_schema_change` | Snapshot schema-change policy | See [Snapshots](/concepts/snapshots) for strategy combinations, defaults, and safety behavior. ## Custom materialization fields | Field | Description | | -------------- | -------------------------------------------- | | `config` | Arbitrary values passed to `ctx.config` | | `placeholders` | Defaults for runtime `@@@placeholder` tokens | ## Diff fields | Field | Description | | -------------------------- | ------------------------------------------ | | `row_diff_exclude_columns` | Columns excluded from row-level comparison | | `row_diff_tolerances` | Numeric comparison tolerances |