W3cubDocs

/MariaDB

ColumnStore Data Types

ColumnStore supports the following data types:

Numeric Data Types

Datatypes Column Size Description
BOOLEAN 1 byte A synonym for "TINYINT(1)". Supported from version 1.2.0 onwards.
TINYINT 1-byte A very small integer. Numeric value with scale 0. Signed: -126 to +127. Unsigned: 0 to 253.
SMALLINT 2-bytes A small integer. Signed: -32,766 to 32,767. Unsigned: 0 to 65,533.
INTEGER/INT 4-bytes A normal-size integer. Numeric value with scale 0. Signed: -2,147,483,646 to 2,147,483,647. Unsigned: 0 to 4,294,967,293
BIGINT 8-bytes A large integer. Numeric value with scale 0. Signed: -9,223,372,036,854,775,806 to+9,223,372,036,854,775,807 Unsigned: 0 to +18,446,744,073,709,551,613
DECIMAL/NUMERIC 2, 4, or 8 bytes A packed fixed-point number that can have a specific total number of digits and with a set number of digits after a decimal. The maximum precision (total number of digits) that can be specified is 18.
FLOAT 4 bytes Stored in 32-bit IEEE-754 floating point format. As such, the number of significant digits is about 6and the range of values is approximately +/- 1e38.The MySQL extension to specify precision and scale is not supported.
DOUBLE/REAL 8 bytes Stored in 64-bit IEEE-754 floating point format. As such, the number of significant digits is about 15 and the range of values is approximately +/-1e308. The MySQL extension to specify precision and scale is not supported. “REAL” is a synonym for “DOUBLE”.

String Data Types

Datatypes Column Size Description
CHAR 1, 2, 4, or 8 bytes Holds letters and special characters of fixed length. Max length is 255. Default and minimum size is 1 byte.
VARCHAR 1, 2, 4, or 8 bytes or 8-byte token Holds letters, numbers, and special characters of variable length. Max length = 8000 bytes or characters and minimum length = 1 byte or character.
TINYTEXT 255 bytes Holds a small amount of letters, numbers, and special characters of variable length. Supported from version 1.1.0 onwards.
TINYBLOB 255 bytes Holds a small amount of binary data of variable length. Supported from version 1.1.0 onwards.
TEXT 64 KB Holds letters, numbers, and special characters of variable length. Supported from version 1.1.0 onwards.
BLOB 64 KB Holds binary data of variable length. Supported from version 1.1.0 onwards.
MEDIUMTEXT 16 MB Holds a medium amount of letters, numbers, and special characters of variable length. Supported from version 1.1.0 onwards.
MEDIUMBLOB 16 MB Holds a medium amount of binary data of variable length. Supported from version 1.1.0 onwards.
LONGTEXT 1.96 GB Holds a large amount of letters, numbers, and special characters of variable length. Supported from version 1.1.0 onwards.
LONGBLOB 1.96 GB Holds a large amount of binary data of variable length. Supported from version 1.1.0 onwards.

Date and Time Data Types

Datatypes Column Size Description
DATE 4-bytes Date has year, month, and day. The internal representation of a date is a string of 4 bytes. The first 2 bytes represent the year, .5 bytes the month, and .75 bytes the day in the following format: YYYY-MM-DD. Supported range is 1000-01-01 to 9999-12-31.
DATETIME 8-bytes A date and time combination. Supported range is 1000-01-01 00:00:00 to 9999-12-31 23:59:59. From version 1.2.0 microseconds are also supported.
TIME 8 bytes Holds hour, minute, second and optionally microseconds for time. Supported range is '-838:59:59.999999' to '838:59:59.999999'. Supported from version 1.2.0 onwards.

Notes

  • ColumnStore treats a zero-length string as a NULL value.
  • As with core MariaDB, ColumnStore employs “saturation semantics” on integer values. This means that if a value is inserted into an integer field that is too big/small for it to hold (i.e. it is more negative or more positive than the values indicated above), ColumnStore will “saturate” that value to the min/max value indicated above as appropriate. For example, for a SMALLINT column, if 32800 is attempted, the actual value inserted will be 32767.
  • ColumnStore largest negative and positive numbers appears to be 2 less than what MariaDB supports. ColumnStore reserves these for its internal use and they cannot be used. For example, if there is a need to store -128 in a column, the TINYINT datatype cannot be used; the SMALLINT datatype must be used instead. If the value -128 is inserted into a TINYINT column, ColumnStore will saturate it to -126 (and issue a warning).
  • ColumnStore truncates rather than rounds decimal constants that have too many digits after the decimal point during bulk load and when running SELECT statements. For INSERT and UPDATE, however, the MariaDB parser will round such constants. You should verify that ETL tools used and any INSERT/UPDATEstatements only specify the correct number of decimal digits to avoid potential confusion.
  • An optional display width may be added to the BIGINT, INTEGER/INT, SMALLINT & TINYINT columns. As with core MariaDB tables, this value does not affect the internal storage requirements of the column nor does it affect the valid value ranges.
  • All columns in ColumnStore are nullable and the default value for any column is NULL. You may optionally specify NOT NULL for any column and/or one with a DEFAULT value.
  • Unlike other MariaDB storage engines, the actual storage limit for LONGBLOB/LONGTEXT is 2,100,000,000 bytes instead of 4GB per entry. MariaDB's client API is limited to a row length of 1GB.
Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.

© 2019 MariaDB
Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/columnstore-data-types/