Expand description
Parquet schema definitions and methods to print and parse schema.
§Example
use parquet::{
basic::{ConvertedType, Repetition, Type as PhysicalType},
schema::{parser, printer, types::Type},
};
use std::sync::Arc;
// Create the following schema:
//
// message schema {
// OPTIONAL BYTE_ARRAY a (UTF8);
// REQUIRED INT32 b;
// }
let field_a = Type::primitive_type_builder("a", PhysicalType::BYTE_ARRAY)
.with_converted_type(ConvertedType::UTF8)
.with_repetition(Repetition::OPTIONAL)
.build()
.unwrap();
let field_b = Type::primitive_type_builder("b", PhysicalType::INT32)
.with_repetition(Repetition::REQUIRED)
.build()
.unwrap();
let schema = Type::group_type_builder("schema")
.with_fields(vec![Arc::new(field_a), Arc::new(field_b)])
.build()
.unwrap();
let mut buf = Vec::new();
// Print schema into buffer
printer::print_schema(&mut buf, &schema);
// Parse schema from the string
let string_schema = String::from_utf8(buf).unwrap();
let parsed_schema = parser::parse_message_type(&string_schema).unwrap();
assert_eq!(schema, parsed_schema);
Modules§
- Parquet schema parser. Provides methods to parse and validate string message type into Parquet
Type
. - Parquet schema printer. Provides methods to print Parquet file schema and list file metadata.
- Contains structs and methods to build Parquet schema and schema descriptors.