# Shared input settings

ignore_unknown_fields allows an input codec to skip keys or header names outside the destination schema. It applies only to the named formats listed in the table.

This option does not infer new columns or remove native type validation from known fields. Positional width and container validity are governed by each codec's own rules.

Use a statement `SETTINGS` clause. Defaults in `system.settings` are read-only;
format settings cannot be persisted with `SET`. Put input settings before
`FORMAT`, because the bytes after the format name are input data.

## arrow_ignore_case

Type: `Bool`

Default value: `0`

Ignore ASCII case when matching input field names to target columns.

Applies to: `arrow`, `arrow_stream`.

## arrow_missing_as_default

Type: `Bool`

Default value: `1`

Give target columns absent from the input schema their DEFAULT; when off, reject missing columns.

Applies to: `arrow`, `arrow_stream`.

## ignore_unknown_fields

Type: `Bool`

Default value: `0`

Skip input keys and header names that match no target column instead of failing.

Applies to: `arrow`, `arrow_stream`, `csv_with_names`, `csv_with_names_and_types`, `custom_separated_with_names`, `form`, `json`, `json_columns`, `json_compact_each_row_with_names_and_types`, `json_each_row`, `json_object_each_row`, `json_strings_each_row`, `parquet`, `row_binary_with_names_and_types`, `tab_separated_with_names`, `tab_separated_with_names_and_types`, `tskv`, `yaml`.

## parquet_detect_variant

Type: `Bool`

Default value: `1`

Recognize unannotated metadata/value binary structs as Variant values.

Applies to: `parquet`.

## parquet_ignore_case

Type: `Bool`

Default value: `0`

Ignore ASCII case when matching input fields to target column names.

Applies to: `parquet`.

## parquet_missing_as_default

Type: `Bool`

Default value: `1`

Give missing input fields their SQL DEFAULT or native type default.

Applies to: `parquet`.

## parquet_parse_json

Type: `Bool`

Default value: `1`

Decode JSON-annotated input fields as native JSON instead of text.

Applies to: `parquet`.

## parquet_read_bytes

Type: `UInt64`

Default value: `16744704`

Target decoded batch bytes estimated from uncompressed row-group metadata.

Applies to: `parquet`.

## parquet_read_geo

Type: `Bool`

Default value: `1`

Decode WKB or WKT columns identified by GeoParquet metadata; text and binary targets retain raw payloads.

Applies to: `parquet`.

## parquet_read_rows

Type: `UInt64`

Default value: `65409`

Maximum rows per decoded input batch.

Applies to: `parquet`.

## snappy_mode

Type: `String`

Default value: `basic`

Read Snappy client files as basic (Hadoop blocks) or framed (standard streaming format).

Applies to: `arrow`, `arrow_stream`, `avro`, `avro_confluent`, `bson_each_row`, `csv`, `csv_with_names`, `csv_with_names_and_types`, `custom_separated`, `custom_separated_with_names`, `form`, `geo_json`, `hive_text`, `json`, `json_as_object`, `json_as_string`, `json_columns`, `json_compact_columns`, `json_compact_each_row`, `json_compact_each_row_with_names_and_types`, `json_compact_strings_each_row`, `json_each_row`, `json_object_each_row`, `json_strings_each_row`, `line_as_string`, `msg_pack`, `npy`, `parquet`, `parquet_metadata`, `protobuf`, `regexp`, `row_binary`, `row_binary_with_names`, `row_binary_with_names_and_types`, `sql_values`, `sqlite`, `tab_separated`, `tab_separated_raw`, `tab_separated_with_names`, `tab_separated_with_names_and_types`, `template`, `tskv`, `yaml`.

## sqlite_read_table

Type: `String`

Default value: `''`

Read this table from the input database; empty selects its first user table.

Applies to: `sqlite`.