Parquet - Hadoop: The Definitive Guide - page 436

Table 13-2. Parquet logical types

Logical type annotation Description Schema example

A UTF-8 character string. Annotates binary .

UTF8

message m {
required
binary a
(UTF8);
}

A set of named values. Annotates binary .

ENUM

message m {
required
binary a
(ENUM);
}

DECIMAL( precision , scale ) An arbitrary-precision signed decimal number. An-
notates int32 , int64 , binary , or
fixed_len_byte_array .

message m {
required
int32 a
(DECIMAL(5,2));
}

A date with no time value. Annotates int32 . Repres-
ented by the number of days since the Unix epoch
(January 1, 1970).

DATE

message m {
required
int32 a (DATE);
}

An ordered collection of values. Annotates group .

LIST

message m {
required
group a (LIST)
{

repeated
group list {
required
int32 element;
}

}

}

An unordered collection of key-value pairs. Annot-
ates group .

MAP

message m {
required
group a (MAP) {
repeated
group
key_value {
required
binary key
(UTF8);
optional
int32 value;
}