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字段类型

基础数据类型

基础数据类型 描述 示例
TINYINT It has 1 byte from -128 to 127. The postfix is Y. It is used as a small range of numbers. 10Y
SMALLINT It has 2 bytes from -32,768 to 32,767. The postfix is S. It is used as a regular descriptive number. 10S
INT It has 4 bytes from -2,147,483,648 to 2,147,483,647. 10
BIGINT It has 8 bytes from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807. The postfix is L. 100L
FLOAT This is a 4-byte single precision floating point number from 1.40129846432481707e-45 to 3.40282346638528860e+38 (positive or negative). Scientific notation is not yet supported. It stores very close approximations of numeric values. 1.2345679
DOUBLE This is an 8-byte double precision floating point number from 4.94065645841246544e-324d to 1.79769313486231570e+308d (positive or negative). Scientific notation is not yet supported. It stores very close approximations of numeric values. 1.2345678901234567
DECIMAL This was introduced in Hive 0.11.0 with a hardcode precision of 38 digits. Hive 0.13.0 introduced user definable precision and scale. It is around 1039 - 1 to 1 - 1038. Decimal data types store exact representations of numeric values. The default definition of this type is decimal(10,0). DECIMAL (3,2) for 3.14
BINARY This was introduced in Hive 0.8.0 and only supports CAST to STRING and vice versa. 1011
BOOLEAN This is a TRUE or FALSE value. TRUE
STRING This includes characters expressed with either single quotes (‘) or double quotes (“). Hive uses C-style escaping within the strings. The max size is around 2G. ‘Books’ or “Books”
CHAR This is available starting with Hive 0.13.0. Most UDF will work for this type after Hive 0.14.0. The maximum length is fixed at 255. ‘US’ or “US”
VARCHAR This is available starting with Hive 0.12.0. Most UDF will work for this type after Hive 0.14.0. The maximum length is fixed at 65355. If a string value being converted/assigned to a varchar value exceeds the length specified, the string is silently truncated. ‘Books’ or “Books”
DATE This describes a specific year, month, and day in the format of YYYY MM-DD. It is available since Hive 0.12.0. The range of date is from 0000-01-01 to 9999-12-31. ‘2013-01-01’
TIMESTAMP This describes a specific year, month, day, hours, minutes, seconds, and milliseconds in the format of YYYY-MM-DD HH:MM:SS[.fff…]. It is available since Hive 0.8.0. ‘2013-01-01 12:00:01.345

复杂数据类型

复杂数据类型 描述 示例
ARRAY This is a list of items of the same type, such as (val1, val2, and so on). You can access the value using array_name[index], for example, fruit[0]='apple'. [‘apple’,‘orange’,‘mango’]
MAP This is a set of key-value pairs, such as (key1, val1, key2, val2, and so on). You can access the value using map_name[key], for example, fruit[1]="apple". {1: “apple”,2: “orange”}
STRUCT This is a user-defined structure of any type of fields, such as {val1, val2, val3, and so on}. By default, STRUCT field names will be col1, col2, and so on. You can access the value using structs_name.column_name, for example, fruit.col1=1. {1, “apple”}
NAMED STRUCT This is a user-defined structure of any number of typed fields, such as (name1, val1, name2, val2, and so on). You can access the value using structs_name.column_name, for example, fruit.apple="gala". {“apple”:“gala”,“weight kg”:1}
UNION This is a structure that has exactly any one of the specified data types. It is available since Hive 0.7.0. It is not commonly used. {2:[“apple”,“orange”]}