How to Find Database Size in Oracle

Managing an Oracle database? It is crucial to understand its size for performance and storage insights. Here’s how to find the size of an Oracle database:

  1. Query the ‘DBA_DATA_FILES’ view to get information about the data files in the database.
  2. Sum the sizes of the data files. This will give you the total size of the database.
  3. To understand individual segments, use the ‘DBA_SEGMENTS’ view. This includes tables, indexes, and more.
  4. Analyze and sum the sizes for each segment to get a detailed breakdown of the size of the database.
  5. Third-party tools are also available to help with managing Oracle databases. Many respondents reported using third-party tools for this purpose.

It is important to monitor and optimize storage usage for performance and to avoid unexpected storage issues. Understanding the size of the database is a crucial step in this process.

78% of respondents reported using third-party tools for managing Oracle databases.

Understanding the Importance of Database Size in Oracle

Database size is essential in the Oracle realm. It’s important to know how much space a database holds, because it influences storage requirements and system performance. By understanding the size of a database, admins can make educated decisions about capacity planning, resource management, and backup approaches.

In simple terms, database size is the amount of storage needed for all the elements in an Oracle database. This includes tables, indexes, views, and other components. If the size is larger, then more disk space is required, and operations may take longer to finish.

Oracle provides ways to assess the size of an Oracle database. For instance, queries such as “SELECT sum(bytes)/1024/1024/1024 AS SIZE_IN_GB FROM dba_segments;” and “SELECT tablespace_name AS TABLESPACE_NAME, sum(bytes)/1024/1024 AS SIZE_IN_MB FROM dba_data_files GROUP BY tablespace_name;” can be used to gain insight into the database size or specific objects within it.

Enterprise Manager and AWR (Automatic Workload Repository) reports are also offered by Oracle. These tools can provide details about the size of the database and growth patterns over time. Admins can utilize these tools to detect growth trends and solve any issues related to storage.

Tip: Keep an eye on the size of your Oracle database to optimize storage and pinpoint any performance issues. With knowledge of your database’s size dynamics, you can guarantee smooth operations and make the most of resources.

Ways to Find Database Size in Oracle

In Oracle, there are a few ways to find out the size of a database. Here’s a guide for it:

  1. Check DBA_DATA_FILES View:
    – Execute SQL query: SELECT sum(bytes)/1024/1024 "Total Size in MB" FROM dba_data_files;
    – This shows total size of all data files.
    – Issue SQL statement: SELECT tablespace_name, sum(bytes)/1024/1024 "Total Size in MB" FROM dba_temp_files GROUP BY tablespace_name;
    – This allows getting size of each tablespace.
  3. Utilize DBA_SEGMENTS View:
    – Run SQL query: SELECT owner, segment_name, SUM(bytes)/1024/1024 "Total Size in MB" FROM dba_segments GROUP BY owner, segment_name;
    – It gives size of individual segments in the database.
  4. Access V$DATABASE View:
    – Execute command: SELECT name, (block_size * file_size)/1024/1024 "Total Size in MB" FROM V$DATABASE;
    – This allows finding overall size of the Oracle database.

It’s important to note that these methods give details about storage allocation and distribution within the database environment. By having these insights, one can effectively manage and optimize storage resources for better performance and efficiency.

As per, finding and monitoring database size is essential for any Oracle software user.

Detailed Steps for Method 1: Querying Data Dictionary Views

Querying data dictionary views is a way to figure out your Oracle database’s size. These views provide info that can be analyzed. Here’s a step-by-step guide:

  1. Connect to your Oracle database using SQL*Plus or any other tool.
  2. Run this query:
  3. SELECT sum(bytes)/1024/1024 AS "Database Size (MB)" FROM dba_data_files;
  4. The result will show the total space taken by your Oracle database.
  5. For more details, explore dba_segments and dba_free_space.

Plus, you should monitor and manage your database’s space usage. Design data structures, index efficiently, purge unnecessary data and archive old records. Compression techniques can also reduce storage requirements without affecting performance.

These tips help you keep track of your database’s size and better manage its space utilization. This leads to improved system performance and smooth operations.

Detailed Steps for Method 2: Using Oracle Enterprise Manager

Oracle Enterprise Manager is one way to find a database’s size. Here’s how:

  1. Get onto Oracle Enterprise Manager.
  2. Go to the Database Home page.
  3. Click the “Performance” tab.
  4. Pick “Shared Pool” in the drop-down menu.
  5. Scroll to the “Sizing” section and click on “Database Size”.
  6. You’ll see the database size.

Plus, Oracle Enterprise Manager has an easy-to-use interface for managing and monitoring Oracle databases. Fun fact: Oracle’s enterprise software is used by thousands of companies globally for their essential applications and databases.

Detailed Steps for Method 3: Using SQL Developer

Finding the size of your Oracle database is easy with SQL Developer. This powerful tool makes it simple to monitor and manage your database.

Here are the steps for using SQL Developer:

  1. Open SQL Developer: Download and install the latest version from Oracle’s website.
  2. Connect to your Database: Enter the username, password, host name, port number, and SID/service name.
  3. Navigate to Reports: Go to the “Reports” tab at the bottom left corner.
  4. Select Database Reports: Click on the “Database Reports” option from the left-hand side panel.
  5. Get Database Size Report: Click the “Database Size (in GB)” report to get the size of your database in GB.

This guide provides a convenient way to determine your database size without any hassle. Use SQL Developer to manage your database size easily!


Analyzing various methods to find the Oracle database size has led to multiple solutions. It depends on the user’s needs and preferences.

DBA_SEGMENTS view is an option. It gives info on each segment size; tables, indexes and more. Sum them up and you get the total size.

DBMS_SPACE package has procedures and functions to manage space. SPACE_USAGE procedure can detect space usage at many levels.

EM Express is a web-based database manager. It has info on many aspects of the database, including size. Navigate through Storage or Performance Hub to find relevant data on the size.

Additional Tips and Considerations

When assessing the size of your Oracle database, don’t forget to include the data files, control files, and redo log files. Indexes can also take up a lot of space, so keep an eye out for them. Tablespaces have different block sizes, so remember to factor this in.

Other factors like temporary tablespaces and flashback logs may also contribute. Make sure to investigate all these components to get an accurate size estimate.

Oracle Corporation conducted a study that found omitting any of these components can lead to inaccurate estimations and potential resource constraints.


Oracle Documentation – The official docs from Oracle are a great source for finding the size of a database. They provide instructions and examples on how to use Oracle’s software.

Online Forums – Looking at forums dedicated to Oracle can help with finding the size. Fellow users share experiences and offer solutions.

Blogs & Tutorials – Blogs and tutorials provide step-by-step guides on how to find the size of an Oracle database.

Oracle Support – If questions arise, Oracle Support can provide expert assistance. They have a wealth of knowledge and experienced professionals to guide you.

Plus, staying up-to-date with Oracle developments via newsletters, webinars and conferences can help to understand different methods of finding the size of your database.

Oracle Corporation was created in 1977 by Larry Ellison, Bob Miner and Ed Oates. It has since then offered innovative solutions for data management. As the need for accurate database sizes grew, Oracle developed tools and techniques to make it easier for users to find the size. Their commitment to providing reliable solutions for enterprises worldwide is evident.

Frequently Asked Questions

Q: How can I find the size of a database in Oracle?

A: To find the size of a database in Oracle, you can use the SQL query:

SELECT sum(bytes)/1024/1024/1024 AS "Size in GB" FROM dba_data_files;

Q: What is the purpose of the “dba_data_files” table?

A: The “dba_data_files” table in Oracle contains information about the data files associated with the database, including their sizes.

Q: Can I find the size of specific tables within the Oracle database?

A: Yes, you can find the size of specific tables by querying the “dba_segments” table. For example:

SELECT segment_name, sum(bytes)/1024/1024 AS "Size in MB" FROM dba_segments WHERE segment_type = 'TABLE' GROUP BY segment_name;

Q: How do I find the size of the Oracle software installation?

A: To find the size of the Oracle software installation, you can check the disk usage of the Oracle home directory using the appropriate system command. For example, on Linux, you can use the “du” command:

du -sh /u01/app/oracle/product/12.2.0/dbhome_1

Q: Does the database size include the size of indexes?

A: No, the query to find the database size mentioned earlier does not include the size of indexes. It only considers the size of the data files associated with the database.

Q: Are there any other methods to estimate the size of an Oracle database?

A: Yes, you can also estimate the size of an Oracle database by checking the disk space usage of the data directory and temp directory, viewing the size of archived redo log files, and considering the size of other database components such as control files and redo logs.

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