Binary large objects, or blobs, are chunks of binary data stored on a database program. In databases, the most common pieces of information are strings, or lines of text. A blob is a section of binary that is able to store images, videos, programs, and other pieces of information on the database. They are able to hold varied data, so blobs are often more memory-heavy than other information in a database. Each database program has a different memory threshold for blobs, and some databases do not allow blob use.
In database programs, the most common information consists of letters or numbers. These are organized as characters, strings and integers. Unlike these other pieces of data, blobs are composed of binary, or 1's and 0's, which are used to create a variety of media files.
In a blob, binary coding is stored as a single entity. This entity is often a file, but it also can be an entire program. Typical files made into blobs are videos, images and audio files, which make the database itself much more varied. By using a blob, a programmer will be able to expand a database from just holding characters to being able to hold media for storage.
Character files and blobs can be combined for organization. For example, if the administrator imports a couple blob images, it can be confusing to figure out which image is which. A string can be placed under the image, which acts as a title for the image.
Strings and integers in databases are only made from characters, so they often use only a tiny amount of memory. Blobs take up a substantially higher amount of memory, because the files are more intensive and require more characters than a string or integer. Using a large volume of blob objects can slow down a database, which is why there is usually a limit to the amount of memory a blob can use.
Blob files in most databases have a memory threshold. For most databases, this ranges from several hundred megabytes (MB) to a few gigabytes (GB). A higher threshold means more blob objects can be made but, at the same time, increases the chance that the blob will slow down the database.
Some database systems do not allow blob use. This is uncommon, because blobs allow administrators to store virtually any type of file. For databases that are not set up to include blob architecture, there is no way to include media files in the database.
