BLOb

What is a BLOb?

BLOb, Binary Large OBject : is a collection of binary data stored as a single entity in a database management system. Blobs are typically images, audio or other multimedia objects. Database support for blobs is not universal. Blobs were originally just big amorphous chunks of data invented by Jim Starkey at DEC(Digital Equipment Corporation)

The four BLOB types are

  • TINYBLOB : A BLOB column with a maximum length of 255 (28 – 1) bytes. Each TINYBLOB value is stored using a one-byte length prefix that indicates the number of bytes in the value
  • BLOB : A BLOB[(M)] column with a maximum length of 65,535 (216 – 1) bytes. Each BLOB value is stored using a two-byte length prefix that indicates the number of bytes in the value.
    An optional length M can be given for this type. I
  • MEDIUMBLOB : A BLOB column with a maximum length of 16,777,215 (224 – 1) bytes. Each MEDIUMBLOB value is stored using a three-byte length prefix that indicates the number of bytes in the value.
  • LONGBLOB : A BLOB column with a maximum length of 4,294,967,295 bytes or 4GB (232 – 1). Each LONGBLOB value is stored using a four-byte length prefix that indicates the number of bytes in the value.
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