VARBINARYn

VARBINARY is a data type used in several relational database management systems to store variable-length binary data. It is intended for non-text binary content such as images, documents, encrypted values, or arbitrary byte streams. The literal usage is often VARBINARY(n), where n indicates the maximum number of bytes for the value. Some systems also support VARBINARY(MAX) or a similar “unbounded” form.

In SQL Server, VARBINARY(n) accepts n from 0 to 8000, with VARBINARY(MAX) available for values up to 2^31-1 bytes. If data exceeds the n value when using VARBINARY(n), it cannot be stored unless a MAX form is used. In MySQL, VARBINARY(M) supports M in the range 0 to 65535, with larger binary data typically stored in BLOB types. Other systems may have different limits or equivalents.

PostgreSQL does not implement VARBINARY as a distinct type; instead, binary data is stored using the BYTEA type, which handles binary strings of variable length without a separate length parameter.

Storage and performance characteristics vary by system. VARBINARY values occupy space proportional to their actual length plus minor overhead, and very large values can impact I/O and indexing options. While you can index VARBINARY columns in some databases, indexing binary data is often less selective than indexing textual data, so design choices may favor storing identifiers, checksums, or hashed representations in indexes.

Common use cases include storing binary large objects, file signatures, or encrypted values in a table column, where the exact length is not fixed. When choosing a data type, consult the specific database documentation for exact limits and behaviors.