How is the usage of Oracle Parallel?

Oracle Parallel is a feature of the Oracle database that allows users to utilize multiple processors or servers simultaneously to speed up data processing and queries. It enables queries, data loading, index creation, and other tasks to be executed on multiple CPUs or servers at the same time, thereby enhancing the performance and throughput of the database.

Using Oracle Parallel can provide the following benefits:

1. Improve query performance by utilizing multiple processors or servers to execute query statements, which can speed up the process, especially for complex queries involving large amounts of data.
2. Speeding up data loading: In the process of loading large amounts of data, parallel operations can be used to load multiple data blocks simultaneously, thereby increasing the speed of data loading.
3. Increase indexing speed: when creating an index, parallel operations can be used to simultaneously process multiple data blocks, thus speeding up the index creation process.
4. Speed up data backup and recovery: By using parallel operations to simultaneously process multiple data files during the backup and recovery process, the speed of backup and recovery can be increased.

Oracle Parallel can be configured and used in the following ways:

1. Parallel queries: Using the keyword “PARALLEL” in a query statement allows for specifying parallel queries, where the number of threads for the parallel queries can be controlled by setting the degree of parallelism.
2. Parallel loading: when using Oracle data loading tools such as SQL*Loader, the number of threads for parallel loading can be controlled by setting the parallelism parameter.
3. Parallel index creation: When creating an index, the number of threads for parallel index creation can be controlled by setting the parallelism parameter.
4. Parallel Backup and Recovery: When using Oracle backup and recovery tools like RMAN, you can control the number of threads for parallel backup and recovery by setting the parallelism parameter.

It is important to note that parallel operations may increase the consumption of system resources, such as CPU, memory, and disk. Therefore, adjustments and optimizations should be made based on the actual situation of the system when configuring and using Oracle Parallel to fully utilize its performance advantages.