VARBINARY

VARBINARY is a variable-length binary data type used in SQL databases to store raw bytes. It is intended for binary data that does not have a fixed size, such as small files, cryptographic hashes, or serialized binary objects. Unlike character types, VARBINARY stores data as bytes rather than text characters.

In most database systems, VARBINARY is declared with a length that specifies the maximum number of bytes it can hold. For example, VARBINARY(255) allows up to 255 bytes, while VARBINARY(65535) permits up to 65,535 bytes in some implementations. Some engines also offer a VARBINARY(MAX) option to indicate a value that can grow beyond a fixed upper limit, typically up to the database’s maximum capacity. The actual storage used equals the length of the stored data plus a small amount of overhead for length information.

VARBINARY is often contrasted with BINARY, which is fixed-length, and with binary large object (BLOB) types, which are designed for very large binary data. In many systems, data stored as VARBINARY may be kept inline with other row data for small values, while larger values can be stored off-row, depending on the database engine and configuration.

Portability varies by database. Some systems support VARBINARY directly (such as MySQL and SQL Server), while others use alternative types (for example, PostgreSQL uses BYTEA rather than VARBINARY). When designing schemas for cross-database compatibility, it is important to consult the specific documentation for the target system to determine the exact behavior and limits of VARBINARY.