AnalyticDB for PostgreSQL provides parallel query for individual tables. This topic describes the parallel query feature.
Introduction
If your instance uses compute nodes that have 4 cores or higher specifications, parallel query is enabled by default for individual table queries to improve multi-core concurrency and reduce query time. The system automatically selects the degree of parallelism based on the number of concurrent queries, compute node specifications, and SQL statements. When the system detects a high workload, it disables parallel query. In low-concurrency scenarios, aggregate queries on individual tables that have large amounts of data can reduce the query time by about 50%.
- Make sure that the minor version of your instance is 6.3.4.0 or later. For more information about how to update the minor version, see Update the minor kernel version of an AnalyticDB for PostgreSQL instance.
- Parallel query can be used for instances whose compute nodes have 4 cores or higher specifications.
Example
In this example, an AnalyticDB for PostgreSQL instance that has the following configurations is used:
- Compute node specifications: 4C32G
- Number of compute nodes: 4
Query time of individual tables before and after parallel acceleration for 10 GB data:
- Before parallel acceleration
- After parallel acceleration
| Before parallel acceleration | After parallel acceleration |
|---|---|
| 17456.066 ms | 9407.291 ms |