PostgreSQL 10 High Performance - Third Edition

SSDs

The latest drive technology on the market right now is solid state drives (SSDs), also called flash disks. These provide permanent memory storage without any moving parts. They can vastly outperform disks with moving parts, particularly for applications where disk seeking is important—often the case for databases—and they should be more reliable too.

There are three major reasons why more databases don't use SSD technology yet:

• Maximum storage capacity is low, and databases tend to be big
• Cost of the storage you do get is fairly high
• Most SSD designs do not have a well designed write-cache on them

Due to how the erasing mechanism on an SSD works, you must have a write cache—typically a few kilobytes, to match the block size of the ...