I recently wrote about the difference between retrospective and prospective search technologies. Now, John Battelle has hinted at an excellent example of a specific prospective search that many people will be interested in. In his blog entry "Google Filing Watch" Battelle points out that since Google has more than 500 shareholders, it will be forced to file statements with the SEC by April 30 of this year. Given the interest in Google, there are many who will want to see, and blog about, whatever Google files as soon as it becomes publicly available on the SEC Edgar site. But, it isn't there yet. (You can check... by doing a "retrospective" search on the site.) Yet, it will appear sometime in the future. So, the easiest thing to do is create a "prospective" search subscription at PubSub.com's SEC Edgar service.
Continue reading "Searching the future for Google..." »
We've been finding that a significant percentage of the people with whom we discuss PubSub.com seem to most easily understand the idea of "Publish and Subscribe" when it is described as a form of "search". Thus, we're finding ourselves using the "Searching the Future" line quite a bit... This is a bit surprising since in the technical community, publish/subscribe has traditionally been seen primarily as a messaging technology. It has become clear to us that the pervasiveness of search tools such as Google is impacting not only the way we use the Internet, but also the way that many people think about it.
Since publish/subscribe systems are, in fact, very similar to search systems, I wouldn't object to the comparison except that as it turns out, there are quite a number of fairly important differences between what we do with the kind of publish/subscribe systems we build at PubSub.com and what is done by the search engines of folk like Google, AltaVista, Yahoo! and soon Microsoft. This note will attempt to begin to describe some of the differences between "traditional" search and the kind of "search" that is done by a PubSub system.
First, let me coin some terms so that it is easier to talk about these two styles of search:
- Retrospective Search: That which is done by traditional search engines -- "Searching the past". This kind of search typically relies on net crawlers, spiders or other data entry methods to gather files into a historical, searchable collection. While the collection changes over time, at the time of any specific "search", the collection can be considered to be static. Any single search query will only be evaluated against those documents that were collected prior to the moment the query was submitted to the search engine. On the other hand, the queries in such a system are constantly changing and are thus dynamic.
- Prospective Search: What PubSub does -- "Searching the future". This kind of search can depend on a wide variety of means to gather newly updated documents but does not rely on a static, historical collection. In a prospective search, a query is registered in a collection of queries and then evaluated against every new document as it is discovered. Thus, while the query is static, the collection of documents against which it is evaluated is dynamic. Also, the entire collection of currently active queries can be considered "static" at the moment that any new document arrives in the system.
Continue reading "Retrospective vs Prospective Search (Past vs Future)" »
