Delay between cache date and changing SERP position

[johnhh]

Hi
One thing I have always wondered - if an existing page changes and is re-visited by the google bot is there a time period between the date of cache and any SERP position change, or is it instant.

Assuming that the SERP position is at least initially based on a cached copy or information based on the cached copy date.

[tedster]

Notice that the links to cached pages are coded by IP address? Google's publicly visible cache of a page is stored in a different area than the area where ranking calculations are done.

From what I've seen, ranking changes come first and updating the page on the cache server can lag behind by days.

[tedster]

Thinking about your question a bit more, let's assume that Google has a primary cache, shared by all the various spiders they send out. This is not the publicly accessible cache that I talked about above, but the "real" cache.

Once Google gets the raw data back from the spiders, there's a lot of processing that needs to happen. To do what they do, Google just can't run the same way we can run a local copy of a single database. The issues of scale are enormous! You can get some idea of the complexity by checking into the patent we discuss on this thread [webmasterworld.com].

So the answer is that Google's processing is amazingly fast, but far from instantaneous. They need to run all kinds of processes and push the data around between over half a million individual servers.

[johnhh]

<quote>ranking changes come first and updating the page on the cache server can lag behind by days</quote>
Thats interesting I had assumed it was the other way around, for the same reason - one of scale. Personally I think the central cache is a given.

The reason for asking was that our web host moved us across borders to another country and as the common practice is .com to be hosted in the US, .de to be hosted in Germany, .co.uk to be hosted in the UK etc, I had expected a drop in ranking that did not happen.

I'll probably move web hosts anyway - but I was suprised.

Or maybe the bad news on our rank position is to be at a later date ?