Google Uses Faster Storage For High Demand Pages
https://www.searchenginejournal.comGoogle’s Gary Illyes reveals the search index uses a tiered system where the most popular content is indexed on faster, more expensive storage.
This topic is discussed in the latest episode of Google’s Search Off the Record podcast which deals with language complexities in search index selection.
In explaining how Google builds its search index, Illyes says content is indexed on three types of storage:
- RAM (Random Access Memory): Fastest and most expensive
- SSD (Solid State Drive): Very fast but cost prohibitive
- HDD (Hard Disk Drive): Slowest and least costly
Google reserves the fastest storage for documents that are likely to be served in search results on a frequent basis.
Content that’s accessed every second will end up being stored on RAM or SSDs. This represents a small amount of Google’s entire index.
The bulk of Google’s index is stored on hard drives because, in Illyes’ words, hard drives are cheap, accessible, and easy to replace.