The "Long-Term Support" edition of Oracle Database 23c brings important improvements to database management, performance, and storage effectiveness. The ability to reduce the size of Bigfile tablespaces is one of Oracle Database 23c's noteworthy features. This enables database managers to maximize storage, recover underutilized space, and enhance the general effectiveness of database operations. Here's a closer look at the new shrink feature, Bigfile tablespaces, and how to make the most of it.

What is a Bigfile Tablespace?

        Using a single data file that can expand to a very high size—up to 128 TB or more, depending on the block size—a bigfile tablespace is a sort of Oracle tablespace made to manage massive volumes of data. By lowering the number of files in the database, bigfile tablespaces make management easier. This is particularly helpful for databases that include enormous datasets. These big files, however, might collect idle space as data usage changes and objects are added or removed, raising storage costs and affecting speed.

Why Shrink Bigfile Tablespaces?

Bigfile tablespace shrinkage solves several important issues:

• Recovering Unused Space: A Bigfile tablespace may have a significant amount of unused space as data is transferred or erased. You can take back this space with the new shrink option, freeing up storage for other purposes.
• Cutting Storage Expenses: Storage is still used for unused space in a Bigfile tablespace. You can optimize space consumption and reduce your overall storage costs by reducing the tablespace.
• Enhancing the Performance of Databases: Performance may be enhanced by a slimmer tablespace since the database engine will have less superfluous data to handle, particularly during backup, recovery, and maintenance procedures. 

Key Features of Bigfile Tablespace Shrinking in Oracle Database 23c

Oracle Database 23c has made it easier to handle huge databases by streamlining the process of decreasing Bigfile tablespaces. Here are a few noteworthy aspects:

• Dynamic Shrinking: To minimize interference with users and applications, you can dynamically reduce the size of a Bigfile tablespace while the database is operational and online.
• Automatic Space Reclamation: Oracle Database 23c eliminates the need for manual monitoring by automatically identifying and recovering unneeded space.
• Flexible Shrinking Options: By letting you choose a target size, the shrink operation makes sure that the tablespace is downsized to suit your requirements.

How to Shrink a Bigfile Tablespace in Oracle Database 23c

In Oracle Database 23c, shrinking a Bigfile tablespace is simple. A detailed tutorial on how to carry out this operation can be found below:

• Determine which Bigfile Tablespace needs to be shrunk.
• To start, find out how much spare space is in your Bigfile tablespace by looking at its current usage. To verify space utilization, use the following query:

Shrink the Bigfile Tablespace

• Use the new ALTER TABLESPACE SHRINK command to shrink the Bigfile tablespace. This command can be customized to shrink to a specific size or automatically reclaim as much space as possible.

• To shrink to a specific target size:

• To automatically reclaim maximum available space:

Verify the Shrink Operation

After the shrink operation completes, verify the results by checking the tablespace size again:

Considerations for Bigfile Tablespace Shrinking

Although reducing the size of a Bigfile tablespace has advantages, there are a few things to think about:

• Data Fragmentation: The shrink operation might not be able to recover all of the space if the tablespace contains fragmented data. To improve space reclamation, a coalescence or rearrangement procedure might be conducted beforehand.
• Storage Thresholds: If you are establishing a target size, be sure that it is sensible. If more data is added later, an excessive amount of shrinking may cause out-of-space issues.
• Performance Impact: Large tablespaces may still see some slowdown during the shrink process, even if Oracle Database 23c reduces the performance impact of shrink operations. If at all possible, run this process at off-peak hours.

Benefits of Bigfile Tablespace Shrinking

• Optimized Storage: By making better use of storage, shrinking Bigfile tablespaces can help cut expenses related to excessive data space usage.
• Better Manageability: The database is easier to administer, backup, and recover by maintaining ideal tablespace sizes, which lowers administrative overhead.
• Improved Performance: By simplifying data access and cutting down on pointless I/O operations, a well-maintained tablespace enhances database performance.

Conclusion

        For DBAs seeking to maximize storage and boost database performance, Oracle Database 23c's new Bigfile tablespace shrinking capability is an effective tool. Bigfile tablespaces are kept affordable and manageable over time via Oracle Database 23c's dynamic shrinking features, customizable settings, and automated space reclamation. This function, which provides a practical means of recovering unneeded space and improving database performance, is particularly helpful in large-scale settings where storage efficiency is crucial.