🧩BLOB

NEW

Also known as: Binary Large Object

A database data type used to store large binary data such as images, audio, or documents.

DESCRIPTION

BLOB stands for Binary Large Object, a data type for unstructured binary content in databases. Many RDBMSs provide BLOB or LOB storage with streaming APIs and size limits. It is used for media, documents, and application assets requiring transactional consistency. Alternatives include storing files in object storage with references in tables. Consider performance, backup size, and access patterns when choosing storage.

ALTERNATIVE DEFINITIONS

Wikipedia

A binary large object (BLOB) is a collection of binary data stored as a single entity in a database management system.

General concept emphasizing storage as a single entity.

Source

MySQL

The BLOB types are TINYBLOB, BLOB, MEDIUMBLOB, and LONGBLOB. A BLOB is a binary large object that can hold a variable amount of data.

Defines concrete BLOB variants and variability in size for MySQL.

Source

Oracle

BLOB (Binary Large Object) data type stores unstructured binary data in the database.

Oracle-specific statement framing BLOB as unstructured binary storage.

Source

RELATED TERMS

Object Storage File Storage Large Object (LOB) VARBINARY Compression Multipart Upload Content Addressable Storage

COMPETING TERMS

CLOB

KNOWLEDGE AREAS

Data Storage & Operations Data Engineering Data Architecture Platform & Tooling

TARGET AUDIENCE

Data Engineer Software Developer Data Architect Cloud Architect

EXTERNAL SOURCES

• Wikipedia - Binary large object
• PostgreSQL - Large Objects interface
• SQLite - BLOB storage class details
• Microsoft Learn - BLOB data in SQL Server

TOP QUESTIONS

When should I store files as BLOBs in a database?

Choose BLOBs for transactional consistency, security, and backup simplicity; prefer object storage for large, static, or CDN-delivered content.

Category: BestPractice

What are common performance issues with BLOBs?

Large row sizes can slow queries and backups. Use streaming APIs, separate tables, or FILESTREAM-like features where available.

Category: Mistakes

How big can a BLOB be?

Limits vary by RDBMS (e.g., MySQL LONGBLOB up to 4GB). Check vendor documentation for exact constraints.

Category: Understanding

How do BLOBs compare to CLOBs?

BLOBs store binary data; CLOBs store character data. Encoding and operations differ accordingly.

Category: Alternatives

How to secure BLOB data?

Apply encryption at rest, access controls, and auditing. Consider application-level encryption for sensitive content.

Category: Security

What backup considerations exist for BLOB-heavy databases?

Backups grow large and slower; consider externalizing to object storage with references to streamline backup and restore.

Category: Operations

Is deduplication useful with BLOBs?

Yes, content-addressable storage or hashing can reduce duplicate storage and speed retrieval for identical assets.

Category: BestPractice

Can I index BLOB data?

You cannot index raw binary content directly; use metadata, checksums, or full-text/feature indexes derived from content.

Category: Understanding

What’s a practical example of BLOB usage?

Storing medical images in a PACS system where transactional consistency and auditing are crucial.

Category: Example