# Data Types

- [Data Type Storage Requirements](/docs/server/reference/data-types/data-type-storage-requirements.md): Reference for storage space usage. This page lists the disk space consumed by each data type, helping with capacity planning and schema optimization.
- [AUTO\_INCREMENT](/docs/server/reference/data-types/auto_increment.md): Complete AUTO\_INCREMENT data type guide for MariaDB. Complete reference for syntax, valid values, storage requirements, and range limits for production use.
- [AUTO\_INCREMENT FAQ](/docs/server/reference/data-types/auto_increment-faq.md): Answers to common questions about AUTO\_INCREMENT. Learn about gaps in sequences, resetting values, and behavior in different storage engines.
- [NULL Values](/docs/server/reference/data-types/null-values.md): Understand the concept of NULL. This page explains how NULL represents missing or unknown data and how it interacts with comparison operators and functions.
- [ROW TYPE OF](/docs/server/reference/data-types/row-type-of.md): Declare row-based variables. This PL/SQL compatibility feature allows declaring variables that match the structure of a table row or cursor.
- [SERIAL](/docs/server/reference/data-types/serial.md): Alias for BIGINT UNSIGNED NOT NULL AUTO\_INCREMENT UNIQUE. This shorthand data type is often used to define primary keys.
- [TYPE OF](/docs/server/reference/data-types/type-of.md): Declare variables based on existing types. This feature allows defining variables or parameters that inherit the data type of a table column or another variable.
- [Numeric Data Types](/docs/server/reference/data-types/numeric-data-types.md): Complete numeric types reference: INT/BIGINT ranges, DECIMAL(M,D) precision/scale, FLOAT/DOUBLE storage sizes, and numeric type selection guidelines.
- [Numeric Data Type Overview](/docs/server/reference/data-types/numeric-data-types/numeric-data-type-overview.md): General introduction to numeric data types. This page summarizes the available integer, fixed-point, and floating-point types and their storage characteristics.
- [BIGINT](/docs/server/reference/data-types/numeric-data-types/bigint.md): Large integer type. A BIGINT uses 8 bytes and can store values from -9223372036854775808 to 9223372036854775807 (signed) or 0 to 18446744073709551615 (unsigned).
- [BIT](/docs/server/reference/data-types/numeric-data-types/bit.md): Bit-field data type. A BIT(M) column stores M bits per value, allowing storage of binary values from 1 to 64 bits in length.
- [BOOL](/docs/server/reference/data-types/numeric-data-types/bool.md): Synonym for TINYINT(1). This type is commonly used to represent boolean values, where 0 is considered false and non-zero values are true.
- [BOOLEAN](/docs/server/reference/data-types/numeric-data-types/boolean.md): Complete BOOLEAN type reference: TINYINT(1) synonym, TRUE/FALSE aliases, CREATE TABLE/SHOW CREATE TABLE output, and IF()/IS operator evaluation.
- [DEC, NUMERIC, FIXED](/docs/server/reference/data-types/numeric-data-types/dec-numeric-fixed.md): Synonyms for DECIMAL. These keywords declare fixed-point numbers, which store exact numeric data with a defined precision and scale.
- [DEC](/docs/server/reference/data-types/numeric-data-types/numeric-data-types-dec.md): Synonym for DECIMAL. This keyword creates a fixed-point column with exact precision, suitable for financial calculations.
- [DECIMAL](/docs/server/reference/data-types/numeric-data-types/decimal.md): Complete DECIMAL type reference: DECIMAL(M,D) syntax, precision limits (M≤65, D≤38), SIGNED/UNSIGNED/ZEROFILL options, and rounding behavior.
- [DOUBLE PRECISION](/docs/server/reference/data-types/numeric-data-types/double-precision.md): Synonym for DOUBLE. This keyword declares a normal-size (8-byte) floating-point number with double precision.
- [DOUBLE](/docs/server/reference/data-types/numeric-data-types/double.md): Double precision floating-point number. A DOUBLE column uses 8 bytes to store large or precise approximate values.
- [FIXED](/docs/server/reference/data-types/numeric-data-types/fixed.md): Synonym for DECIMAL. This keyword is used to define columns that require exact numeric precision, such as currency.
- [FLOAT](/docs/server/reference/data-types/numeric-data-types/float.md): Single precision floating-point number. A FLOAT column uses 4 bytes and stores approximate values with less precision than DOUBLE.
- [FLOAT4](/docs/server/reference/data-types/numeric-data-types/float4.md): Synonym for FLOAT. This keyword declares a single-precision floating-point column.
- [FLOAT8](/docs/server/reference/data-types/numeric-data-types/float8.md): Synonym for DOUBLE. This keyword declares a double-precision floating-point column.
- [Floating-point Accuracy](/docs/server/reference/data-types/numeric-data-types/floating-point-accuracy.md): Explanation of floating-point precision issues. This page details why FLOAT and DOUBLE types are approximate and how rounding errors occur.
- [INT](/docs/server/reference/data-types/numeric-data-types/int.md): Complete INT type reference: INT(M) syntax, signed (-2147483648 to 2147483647) vs unsigned (0 to 4294967295) ranges, and ZEROFILL padding guidelines.
- [INT1](/docs/server/reference/data-types/numeric-data-types/int1.md): Synonym for TINYINT. This type uses 1 byte of storage.
- [INT2](/docs/server/reference/data-types/numeric-data-types/int2.md): Synonym for SMALLINT. This type uses 2 bytes of storage.
- [INT3](/docs/server/reference/data-types/numeric-data-types/int3.md): Synonym for MEDIUMINT. This type uses 3 bytes of storage.
- [INT4](/docs/server/reference/data-types/numeric-data-types/int4.md): Synonym for INT. This type uses 4 bytes of storage.
- [INT8](/docs/server/reference/data-types/numeric-data-types/int8.md): Synonym for BIGINT. This type uses 8 bytes of storage.
- [INTEGER](/docs/server/reference/data-types/numeric-data-types/integer.md): Synonym for INT. This keyword declares a standard 4-byte integer column.
- [MEDIUMINT](/docs/server/reference/data-types/numeric-data-types/mediumint.md): Medium-sized integer. A MEDIUMINT column uses 3 bytes and stores values from -8388608 to 8388607 (signed) or 0 to 16777215 (unsigned).
- [MIDDLEINT](/docs/server/reference/data-types/numeric-data-types/middleint.md): Synonym for MEDIUMINT. This keyword refers to the 3-byte integer type.
- [NUMBER](/docs/server/reference/data-types/numeric-data-types/number.md): Oracle-compatible synonym for DECIMAL. This type is used for fixed-point arithmetic.
- [NUMERIC](/docs/server/reference/data-types/numeric-data-types/numeric.md): Synonym for DECIMAL. This type stores exact numeric data values.
- [REAL](/docs/server/reference/data-types/numeric-data-types/real.md): Synonym for DOUBLE. In standard SQL mode, REAL is a double-precision floating-point number.
- [SMALLINT](/docs/server/reference/data-types/numeric-data-types/smallint.md): Small integer type. A SMALLINT column uses 2 bytes and stores values from -32768 to 32767 (signed) or 0 to 65535 (unsigned).
- [TINYINT](/docs/server/reference/data-types/numeric-data-types/tinyint.md): Very small integer type. A TINYINT column uses 1 byte and stores values from -128 to 127 (signed) or 0 to 255 (unsigned).
- [Date and Time Data Types](/docs/server/reference/data-types/date-and-time-data-types.md): Store temporal values. This section covers data types for dates, times, and timestamps, including DATE, DATETIME, TIMESTAMP, TIME, and YEAR.
- [DATE](/docs/server/reference/data-types/date-and-time-data-types/date.md): Complete DATE type reference: YYYY-MM-DD format, YYMMDD input literals, date range 1000-01-01 to 9999-12-31, and zero-date SQL\_MODE handling.
- [DATETIME](/docs/server/reference/data-types/date-and-time-data-types/datetime.md): Complete DATETIME data type guide for MariaDB. Complete reference for syntax, valid values, storage requirements, and range limits for production use.
- [SQL\_TSI\_YEAR](/docs/server/reference/data-types/date-and-time-data-types/sql_tsi_year.md): Synonym for YEAR. This keyword is an alias used for declaring a column to store year values.
- [TIME](/docs/server/reference/data-types/date-and-time-data-types/time.md): Store time values. This type handles time durations or time of day, ranging from '-838:59:59' to '838:59:59' with optional microsecond precision.
- [TIMESTAMP](/docs/server/reference/data-types/date-and-time-data-types/timestamp.md): Complete TIMESTAMP data type guide for MariaDB. Complete reference for syntax, valid values, storage requirements, and range limits for production use.
- [YEAR Data Type](/docs/server/reference/data-types/date-and-time-data-types/year-data-type.md): Store year values. This type stores a year in 2-digit or 4-digit format, supporting values from 1901 to 2155, and 0000.
- [String Data Types](/docs/server/reference/data-types/string-data-types.md): Store text and binary data. This section covers character types like CHAR, VARCHAR, and TEXT, as well as binary types like BLOB and BINARY.
- [BLOB and TEXT Data Types](/docs/server/reference/data-types/string-data-types/blob-and-text-data-types.md): Overview of large object types. This page compares BLOB (binary) and TEXT (character) types, explaining their storage and usage differences.
- [BINARY](/docs/server/reference/data-types/string-data-types/binary.md): Fixed-length binary string type. This type stores a fixed number of bytes, padding with zero bytes if the data is shorter.
- [BLOB](/docs/server/reference/data-types/string-data-types/blob.md): Variable-length binary large object. BLOB columns can store binary data up to 65,535 bytes, suitable for images or other non-text files.
- [CHAR](/docs/server/reference/data-types/string-data-types/char.md): Fixed-length character string type. CHAR columns store strings of a specified length (0 to 255), padding with spaces if necessary.
- [CHARACTER](/docs/server/reference/data-types/string-data-types/character.md): Fixed-length character string type. CHARACTER columns store strings of a specified length (0 to 255), padding with spaces if necessary.
- [CHAR BYTE](/docs/server/reference/data-types/string-data-types/char-byte.md): Fixed-length binary string type. This type stores a fixed number of bytes, padding with zero bytes if the data is shorter.
- [CHAR VARYING](/docs/server/reference/data-types/string-data-types/char-varying.md)
- [CLOB](/docs/server/reference/data-types/string-data-types/clob.md): In Oracle mode, CLOB is an alias for the LONGTEXT data type used to store large text objects.
- [ENUM](/docs/server/reference/data-types/string-data-types/enum.md): Complete ENUM type reference: ENUM('v1','v2') syntax, CHARACTER SET/COLLATE options, NULL/empty string defaults, and numeric index sorting guidelines.
- [INET4](/docs/server/reference/data-types/string-data-types/inet4.md): IPv4 address data type. Stores IPv4 addresses as 4-byte binary strings for efficient storage and retrieval.
- [INET6](/docs/server/reference/data-types/string-data-types/inet6.md): IPv6 address data type. Stores IPv6 addresses as 16-byte binary strings, also supporting IPv4 addresses via mapping.
- [JSON Data Type](/docs/server/reference/data-types/string-data-types/json.md): Complete JSON Data Type data type guide for MariaDB. Complete reference for syntax, valid values, storage requirements, and range limits for production use.
- [LONG and LONG VARCHAR](/docs/server/reference/data-types/string-data-types/long-and-long-varchar.md): LONG and LONG VARCHAR are compatibility synonyms for the MEDIUMTEXT string data type.
- [LONG CHAR VARYING](/docs/server/reference/data-types/string-data-types/long-char-varying.md): LONG CHAR VARYING is a compatibility synonym for the MEDIUMTEXT string data type.
- [LONG CHARACTER VARYING](/docs/server/reference/data-types/string-data-types/long-character-varying.md): LONG CHARACTER VARYING is a compatibility synonym for the MEDIUMTEXT string data type.
- [LONG VARBINARY](/docs/server/reference/data-types/string-data-types/long-varbinary.md): LONG VARBINARY is a compatibility synonym for the MEDIUMBLOB binary data type.
- [LONG VARCHAR](/docs/server/reference/data-types/string-data-types/long-varchar.md): LONG VARCHAR is a compatibility synonym for the MEDIUMTEXT string data type.
- [LONG VARCHARACTER](/docs/server/reference/data-types/string-data-types/long-varcharacter.md): LONG VARCHARACTER is a compatibility synonym for the MEDIUMTEXT string data type.
- [LONGBLOB](/docs/server/reference/data-types/string-data-types/longblob.md): Very large binary object. A LONGBLOB column can store up to 4GB of binary data.
- [LONGTEXT](/docs/server/reference/data-types/string-data-types/longtext.md): Complete LONGTEXT type reference: 4GB (2^32-1) storage limit, CHARACTER SET/COLLATE syntax, max\_allowed\_packet constraints, and JSON/CLOB aliases.
- [MEDIUMBLOB](/docs/server/reference/data-types/string-data-types/mediumblob.md): Medium-sized binary object. A MEDIUMBLOB column can store up to 16MB of binary data.
- [MEDIUMTEXT](/docs/server/reference/data-types/string-data-types/mediumtext.md): Medium-sized character string. A MEDIUMTEXT column can store up to 16MB of text data.
- [NATIONAL CHAR](/docs/server/reference/data-types/string-data-types/national-char.md): NATIONAL CHAR is a synonym for the CHAR data type that uses the predefined utf8 character set.
- [NATIONAL CHAR VARYING](/docs/server/reference/data-types/string-data-types/national-char-varying.md): NATIONAL CHAR VARYING is a synonym for VARCHAR that uses the predefined utf8 character set.
- [NATIONAL CHARACTER VARYING](/docs/server/reference/data-types/string-data-types/national-character-varying.md): NATIONAL CHARACTER VARYING is a synonym for VARCHAR using the predefined utf8 character set.
- [NATIONAL CHARACTER](/docs/server/reference/data-types/string-data-types/national-character.md): NATIONAL CHARACTER is a synonym for the CHAR data type using the predefined utf8 character set.
- [NATIONAL VARCHAR](/docs/server/reference/data-types/string-data-types/national-varchar.md): NATIONAL VARCHAR is a synonym for the VARCHAR data type using the predefined utf8 character set.
- [NATIONAL VARCHARACTER](/docs/server/reference/data-types/string-data-types/national-varcharacter.md): NATIONAL VARCHARACTER is a synonym for VARCHAR using the predefined utf8 character set.
- [NCHAR](/docs/server/reference/data-types/string-data-types/nchar.md): NCHAR is a synonym for the fixed-length CHAR string data type using the utf8 character set.
- [NCHAR VARCHAR](/docs/server/reference/data-types/string-data-types/nchar-varchar.md): NCHAR VARCHAR is a synonym for the VARCHAR string data type using the utf8 character set.
- [NCHAR VARCHARACTER](/docs/server/reference/data-types/string-data-types/nchar-varcharacter.md): NCHAR VARCHARACTER is a synonym for VARCHAR using the utf8 character set.
- [NCHAR VARYING](/docs/server/reference/data-types/string-data-types/nchar-varying.md): NCHAR VARYING is a synonym for the VARCHAR string data type using the utf8 character set.
- [RAW](/docs/server/reference/data-types/string-data-types/raw.md): In Oracle mode, RAW is a variable-length binary data type synonymous with VARBINARY.
- [ROW](/docs/server/reference/data-types/string-data-types/row.md): ROW is a data type used in stored programs to store a complete row of data from a cursor or table.
- [SET Data Type](/docs/server/reference/data-types/string-data-types/set-data-type.md): String object with zero or more values from a predefined list. A SET column can store multiple values selected from a list of permitted strings.
- [TEXT](/docs/server/reference/data-types/string-data-types/text.md): Complete TEXT type reference: TEXT(M) syntax, 65,535 byte maximum, 2-byte length prefix, DEFAULT value support, and indexing constraints rules.
- [TINYBLOB](/docs/server/reference/data-types/string-data-types/tinyblob.md): Very small binary object. A TINYBLOB column can store up to 255 bytes of binary data.
- [TINYTEXT](/docs/server/reference/data-types/string-data-types/tinytext.md): Very small character string. A TINYTEXT column can store up to 255 characters.
- [UUID Data Type](/docs/server/reference/data-types/string-data-types/uuid-data-type.md): Official UUID data type reference: 128-bit storage optimization, CAST from CHAR/VARCHAR/BINARY types, RFC4122 string format, and UUIDv6/v7 support.
- [VARBINARY](/docs/server/reference/data-types/string-data-types/varbinary.md): Variable-length binary string type. VARBINARY columns store binary strings of variable length up to a specified maximum.
- [VARCHAR](/docs/server/reference/data-types/string-data-types/varchar.md): Complete VARCHAR reference: VARCHAR(M) syntax, length limits (0-65532 per row), CHARACTER SET/COLLATE options, indexing rules, and trailing spaces.
- [VARCHAR2](/docs/server/reference/data-types/string-data-types/varchar2.md): Variable-length character string type. VARCHAR2 columns store strings of variable length up to a specified maximum (up to 65,535).
- [VARCHARACTER](/docs/server/reference/data-types/string-data-types/varcharacter.md): Variable-length character string type. VARCHARACTER columns store strings of variable length up to a specified maximum (up to 65,535).
- [XMLTYPE](/docs/server/reference/data-types/string-data-types/xmltype.md)
- [Character Sets and Collations](/docs/server/reference/data-types/string-data-types/character-sets.md): Learn about character sets in MariaDB Server. This section details how different character sets and collations impact string storage, comparison, and sorting within your database.
- [Character Set and Collation Overview](/docs/server/reference/data-types/string-data-types/character-sets/character-set-and-collation-overview.md): Learn the core concepts of character sets and collations in MariaDB, including how they define string storage and sorting rules.
- [Setting Character Sets and Collations](/docs/server/reference/data-types/string-data-types/character-sets/setting-character-sets-and-collations.md): Complete Setting Character Sets and Collations data type guide for MariaDB. Complete reference for syntax, valid values, storage requirements, and range.
- [Supported Character Sets and Collations](/docs/server/reference/data-types/string-data-types/character-sets/supported-character-sets-and-collations.md): Complete character sets reference: SHOW CHARACTER SET command, information\_schema.CHARACTER\_SETS/COLLATIONS tables, NO PAD queries, and ci/cs flags.
- [Unicode](/docs/server/reference/data-types/string-data-types/character-sets/unicode.md): Explore MariaDB's support for Unicode, covering the differences between the utf8mb3 and utf8mb4 character sets for multi-byte storage.
- [Internationalization and Localization](/docs/server/reference/data-types/string-data-types/character-sets/internationalization-and-localization.md): Discover how MariaDB supports internationalization and localization, enabling databases to store and process data in multiple languages.
- [Coordinated Universal Time](/docs/server/reference/data-types/string-data-types/character-sets/internationalization-and-localization/coordinated-universal-time.md): Coordinated Universal Time (UTC) is the primary time standard by which the world regulates clocks and time, and is the internal storage format for MariaDB timestamp values.
- [Locales Plugin](/docs/server/reference/data-types/string-data-types/character-sets/internationalization-and-localization/locales-plugin.md): The LOCALES plugin enables the INFORMATION\_SCHEMA.LOCALES table and SHOW LOCALES statement, allowing users to view all locales compiled into the server.
- [Server Locale](/docs/server/reference/data-types/string-data-types/character-sets/internationalization-and-localization/server-locale.md): Server locale settings control the language for date and time functions via lc\_time\_names and the language for error messages via lc\_messages.
- [Setting the Language for Error Messages](/docs/server/reference/data-types/string-data-types/character-sets/internationalization-and-localization/setting-the-language-for-error-messages.md): Learn how to configure the lc\_messages and lc\_messages\_dir system variables to display server error messages in a supported local language.
- [Time Zones](/docs/server/reference/data-types/string-data-types/character-sets/internationalization-and-localization/time-zones.md): Complete Time Zones data type guide for MariaDB. Complete reference for syntax, valid values, storage requirements, and range limits for production use.