Data compression algorithms have been around for nearly a century, but only now they are being put to use within mainstream information systems processing.
Oracle has been putting continual effort in developing techniques for compressing data. Advanced compression is the latest feature that comes with Oracle database releases, which takes care of compression of data and thereby provides storage solutions to enterprises. We will learn more about this technology in our three part blog series. In the first blog, we will cover why compression is such a focus in almost all organizations and what benefits it provides.
Image Source: http://www.oracle.com/ocom/groups/public/@otn/documents/digitalasset/2393487.png
Background to Data Compression
Data compression algorithms have been around for nearly a century, but only now they are being put to use within mainstream information systems processing. The cost of maintaining their live production data and the historical Data Warehouse or DSS (Decision Support System) data is an increasing expense for IT department. On the other hand, reaching to the older data is an indispensable requirement for all mainstream companies. As an information company, Oracle’s strategy for decreasing the cost and also improving the performance of accessing either production or historical data has been evolving for many years now reaching maturity levels that no other companies can claim. It started with DSS type data warehousing compression and now we have the chance to compress even the live transactional tables or partitions in our customers Oracle databases.
In early 2000, Oracle started to present a solid Information Life Cycle to its customers, which mainly solves their requirement of moving less accessed data to less expensive storage. While it is true that data storage prices (disks) have fallen dramatically over the last decade (and continue to fall rapidly), Oracle data compression has far more appealing benefits than simply saving on disk storage cost. Because data itself can be highly compressed, information can be fetched off of the disk devices with less physical IO, which radically improves query performance under certain conditions.
Benefits of Compression include:
Reduced Database Storage
The compression ratio achieved in a given environment depends on the structure of the data being compressed, specifically the cardinality of the data. In general, organizations can expect to reduce their storage space consumption by a factor of 2x to 4x by using Advanced Row Compression.
Improved Query Performance
Advanced Row Compression has no adverse impact on read operations. There is additional work performed while writing data, making it impossible to eliminate performance overhead for write operations. However, Oracle has put in a significant amount of work to minimize this overhead for Advanced Row Compression.
Data Compressed in Memory
The benefits of Advanced Row Compression go beyond just on-disk storage savings. One significant advantage is Oracle’s ability to read compressed blocks directly without uncompressing the blocks. This helps improve performance due to the reduction in I/O, and the reduction in system calls related to the I/O operations. Further, the buffer cache becomes more efficient by storing more data without having to add memory.
Faster RMAN Backup and Recovery
Due to RMAN’s tight integration with Oracle Database, backup data that is already compressed by Advanced Compression remains compressed when it is written to disk or tape and doesn’t need to be uncompressed before recovery – providing an enormous reduction in storage and a potentially large reduction in backup and restore times.
In summary, the benefits for ORACLE advanced compression are:
• Up to a 4x disk savings - Depending on the nature of your data, Oracle compression will result in huge savings on disk space. On average, it can save 2x to 4x of disk space.
• Less expensive solid-state disk - As the compressed tables reside on fewer disk blocks, vendors that might not otherwise be able to afford solid-state flash disk can now enjoy I/O speeds up to 300x faster than platter disk.
• Faster full scan/range scan operations - As tables reside on less data blocks, full table scans and index range scans can retrieve the rows with less disk I/O.
• Reduced network traffic - As the data blocks are compressed/decompressed only within Oracle, the external network packets will be significantly smaller.
In Blog 2, we will learn what advanced compression is in Oracle, and how we implement advanced compression in Oracle databases. So far, if you have any questions on the topic then click below: