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…Principal Features…
High performance features
- Cost based optimization
- Access data based on database statistics
- Indexes
- Several types designed to improve query response time and throughput
- Parallel Query
- Spawn multiple processes to create query result
- Parallel DML
- Spawn multiple processes to perform update
- Real Application Clusters
Transparent Distributed Support
- Transparent access to remote data
Notes:
Oracle will support query and update activity on very large databases. In order to accomplish this, many high performance features are built-in. These include:
Cost Based Optimization – Oracle comes with a query optimizer that automatically and transparently optimizes the query access path based on database statistics such as object size.
Indexes – Much like the index in a text book helps you find a specific item in the book, a database index is an object that helps find a row in a table. Oracle provides several index types, each designed for a different type of access or type of data. These include B-Tree, bitmap and function-based indexes.
Parallel Query and Parallel DML – Parallel Query allows a single SQL statement to be processed by several server processes, thus reducing overall response time. This is excellent for I/O intensive operations.
Real Application Clusters – This feature, formerly called Oracle Parallel Server, allows many servers (instances) to access the same set of database files, allowing the processing load to be distributed across many machines.
Oracle supports distributed database, meaning that one can access a table (query or update) on a remote server. Transparency is achieved via database objects called SYNONYMS and DATABASE LINKS.