When should I use BLOB and when should I use TEXT in MySQL?

Understanding BLOB and TEXT Data Types in MySQL

MySQL provides two distinct data types, BLOB (Binary Large OBject) and TEXT, to efficiently store and handle data of varying sizes and types. BLOB is designed for binary data, while TEXT is primarily intended for storing large textual content.

BLOB vs. TEXT

The key difference between BLOB and TEXT lies in their treatment of data. BLOB stores binary data as a sequence of bytes without any character set association. This means that the content is treated as raw binary data, enabling storage of non-textual data such as images, videos, and binary files.

In contrast, TEXT stores data as character strings and maintains a character set association. As such, TEXT is generally used for storing large amounts of textual content, such as articles, documents, or descriptions. The character set governs the encoding and interpretation of the stored text, allowing comparison and sorting based on the intended language and context.

BLOB vs. TEXT Variants

Both BLOB and TEXT have smaller variants, namely SMALLBLOB/SMALLTEXT and MEDIUMBLOB/MEDIUMTEXT. These variants differ in their maximum storage capacity, with SMALL having a limit of 256 bytes, MEDIUM a limit of 16MB, and standard BLOB/TEXT allowing up to 2GB.

MEDIUMBLOB and MEDIUMTEXT

The description "MEDIUMBLOB, MEDIUMTEXT L 3 bytes, where L < 224" refers to the internal representation of these data types. L represents the length of the stored content up to a maximum of 223 bytes. The extra three bytes are used to store the length information. For larger values exceeding 223 bytes, the length is stored in additional bytes as required.

Usage Guidelines

The choice between BLOB and TEXT depends on the specific nature of the data being stored:

• BLOB is suitable for binary data that does not require character set considerations, such as images, videos, and files.
• TEXT is best used for large textual content, including articles, documents, and descriptions, that require character set handling and comparison operations.

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