MySQL, PostgreSQL和Derby的性能比较

MySQL

PostgreSQL

Derby

性能比较

最近在网上有这样一种性能对比:

如下是引用的内容:(我的认为,主要是说明这三种数据库更适合在哪方面的应用.在大吞吐量的数据传送Derby是颇有优点的.)不过要注意,Derby的默认缓存只有4M,必定要改到200M以上才好用.

Performance Evaluation:
MySQL, PostgreSQL and Derby
Evaluated performance of:
? MySQL/InnoDB (version 5.0.10)
? PostgreSQL (version 8.0.3)
? Derby Embedded (version 10.1.1.0)
? Derby Client-Server

Database Configurations
Configurations:
? “Out-of-box” performance
? No tuning, except:
> size of database buffer
> database and transaction
log on separate disks
? No Benchmark
Load:
> 1-100 concurrent clients
Databases:
1. Main-memory database:
> 10 MB user data
> 64 MB database buffer
2. Disk database:
> 10 GB user data
> 64 MB database buffer

Throughput: TPC-B like load
Main-memory database (10 MB):               Disk-based database (10 GB):

Observations
? Derby outperforms MySQL on disk-based databases
> Derby has 100% higher throughput than MySQL
? MySQL performs better on small main-memory
databases
> Update-intensive load: Derby has 20-50% lower
throughput
> Read-intensive load: Derby has 50% lower throughput
? PostgreSQL performs best on read-only databases, and
has lowest throughput on update-intensive databases
Why?

Conclusions: Resource Usage? MySQL performs better than Derby when> The database is small and fits in the database buffer> Throughput becomes CPU-bound> Derby uses more CPU and sends more messages over the net? Derby performs better than MySQL when> The database is large and does not fit in the database buffer> Throughput becomes I/O-bound? PosgreSQL performs best with read-only load> Update-intensive load results in much disk I/O