Character Large Object

Definition of Character Large Object

Character Large Object, often abbreviated as CLOB, is a data type used in databases to store large volumes of text or character-based data. CLOBs can store several gigabytes worth of characters, making them suitable for storing documents, articles, or long strings of text. They are typically used in relational databases, like Oracle and SQL Server, to store and manage unstructured data more efficiently.


The phonetics of the keyword “Character Large Object” is as follows:Character: /ˈkærəktər/Large: /lɑrdʒ/Object: /ˈɒbdʒɪkt/

Key Takeaways

  1. CLOB (Character Large Object) is a data type used to store and manage large volumes of character data, like long text files, XML documents, or JSON structures.
  2. Character Large Objects are typically used in databases to store unstructured data or data that exceeds the storage capacity of traditional data types like VARCHAR or NVARCHAR.
  3. Database systems, such as Oracle, SQL Server, and MySQL, provide specific CLOB manipulation tools and functions, like searching, updating, or extracting data from CLOBs, but performance could be slower compared to operations on smaller-sized data types.

Importance of Character Large Object

Character Large Object, or CLOB, is an important technology term because it denotes a type of data storage in databases explicitly designed for holding vast amounts of textual or alphanumeric data; this is invaluable in today’s rapidly expanding digital landscape.

As businesses and organizations generate and manage increasing quantities of textual data, the need for efficient storage and retrieval systems becomes paramount.

CLOBs fulfill this essential role by storing large amounts of character data, like large documents or formatted text, and enabling efficient querying and manipulation.

Thus, CLOBs contribute significantly to the overall effectiveness of large-scale data management and database systems, consequently enhancing the potentials for data-driven decision-making and diverse applications across multiple industries.


Character Large Object, often abbreviated as CLOB, serves a crucial purpose in the realm of databases, as it enables the storage and management of large amounts of textual data. As opposed to regular fixed-sized data types, such as CHAR and VARCHAR, CLOBs overcome the limitation of size constraints in storing extensive textual information.

With the capacity to hold millions, or even billions, of characters, CLOB proves to be an indispensable tool for enterprises and applications that necessitate managing substantial volumes of unstructured data, such as product descriptions, customer reviews, lengthy articles, or extensive documentation. The utilization of CLOBs in databases like Oracle, MySQL, and SQL Server makes the handling of massive text data more efficient, as it allows for the segregation and storage of this information separately from the regular table structures.

Rather than consuming space within the primary data table, CLOB data can be placed in separate spaces specifically tailored for large objects on disk. This approach ensures optimized performance during the execution of queries and transactions and minimizes delays or interruptions related to the processing of bulky textual data.

Additionally, CLOBs support operations such as searching, extracting, and manipulating text data, thereby facilitating greater flexibility for developers and database administrators in managing and leveraging extensive textual data.

Examples of Character Large Object

Character Large Object (CLOB) is a type of data storage used in databases to store large amounts of text or character-based data. Here are three real-world examples of CLOB usage:

Blogging Platforms: Blogging platforms, such as WordPress, often require large text storage for storing the content of thousands of blog posts written by users. CLOB fields in databases are used in this scenario to store the text content of each blog post, allowing users to write, edit, and publish articles without any constraints on the number of characters.

Social Media Applications: Social media platforms like Facebook and Twitter store vast amounts of textual data, including user posts, comments, and messages. These platforms use CLOB fields to store long texts, enabling users to express their thoughts and engage in discussions without being restricted by character limits.

Customer Relationship Management (CRM) Systems: CRM systems, like Salesforce, store large volumes of textual data related to customer interactions, including emails, call transcripts, and meeting notes. By using CLOB fields, these systems ensure seamless and organized storage of all text-based communication, helping businesses better manage their customer relationships.


Character Large Object FAQ

1. What is a Character Large Object (CLOB)?

A Character Large Object, or CLOB, is a data type used in databases to store large amounts of character data, such as lengthy text documents or other large strings. CLOBs can hold up to several gigabytes of data and are typically used for storing large volumes of text or large XML documents.

2. How are CLOBs different from other data types like VARCHAR?

While both CLOBs and VARCHARs are used to store character data, VARCHAR fields have a size limit, often restricting the maximum amount of text that can be stored. On the other hand, CLOBs can store much larger amounts of data, ranging in size up to a few gigabytes. As a result, CLOBs are suitable for storing much larger text documents or XML files, whereas VARCHARs are better for shorter text strings.

3. What are some common database systems that support CLOBs?

Several popular database systems support CLOB data types, including Oracle, Microsoft SQL Server, IBM DB2, PostgreSQL, and MySQL. However, they may have slightly different naming conventions and syntax for creating and manipulating CLOBs, so it is essential to refer to the documentation specific to your chosen database system for handling CLOBs.

4. How do you create a table with a CLOB field?

Creating a table with a CLOB field involves specifying the CLOB data type when defining the table’s columns. The exact syntax may vary depending on the database system being used, but here’s an example of creating a table with a CLOB column in SQL:

CREATE TABLE example_table (
  large_text CLOB

5. How do you insert data into a CLOB field?

To insert data into a CLOB field, you can use an INSERT statement with the necessary syntax to include the CLOB data. Again, the exact syntax may depend on your chosen database system, but here’s an example of inserting data into a CLOB field:

INSERT INTO example_table (id, large_text)
VALUES (1, 'This is a sample data for the CLOB field');


Related Technology Terms

  • Binary Large Object (BLOB)
  • Structured Query Language (SQL)
  • Database Management System (DBMS)
  • Text storage and retrieval
  • Data type and encoding

Sources for More Information


About The Authors

The DevX Technology Glossary is reviewed by technology experts and writers from our community. Terms and definitions continue to go under updates to stay relevant and up-to-date. These experts help us maintain the almost 10,000+ technology terms on DevX. Our reviewers have a strong technical background in software development, engineering, and startup businesses. They are experts with real-world experience working in the tech industry and academia.

See our full expert review panel.

These experts include:


About Our Editorial Process

At DevX, we’re dedicated to tech entrepreneurship. Our team closely follows industry shifts, new products, AI breakthroughs, technology trends, and funding announcements. Articles undergo thorough editing to ensure accuracy and clarity, reflecting DevX’s style and supporting entrepreneurs in the tech sphere.

See our full editorial policy.

More Technology Terms

Technology Glossary

Table of Contents