1, about the concept of the index:
B grade: also called Shanghai ordinary love library, the page can bring a small amount of traffic to the site, the page in the keyword ranking. How to determine the page into the common library
do Shanghai dragon to analyze the web log, to see the love Shanghai spiders to crawl the web page. I don’t know if you have not found a rule? Love Shanghai spiders can not regularly crawl the site all page links, whether it is not included in the page or have been included in the page, the spider will crawl to love Shanghai, but some page spider often to catch some pages, the spider to frequency is low, this is why?
(1), in the love of Shanghai to search the title of the page, the search results will not appear in the page, because the page did not participate in ranking;
any of the following cases, all belong to the bottom layer in Library:
web page of four grade in Shanghai love eyes, respectively D, C, B, A grade:
judging method of ordinary libraries: < >
D level: love Shanghai spiders crawl the page, but not included in this page. There are 2 reasons, the page content of poor quality, low weight;
We all know that
3, what is love Shanghai quality common library database library??? Here give us a detailed description of
C is also called the bottom level: love love Shanghai library, included the page, but basically will not bring any traffic. How to determine whether the page into the bottom layer with
index of effective means to be loved in Shanghai for effective collection of web pages, and to participate in the ranking page. Love Shanghai is currently in the search results, showing only 760 search results, you search for any keyword, you in the 760 pages of this page, which belongs to the effective collection;
the first to introduce several important concepts of Shanghai dragon, to answer the above questions like Shanghai spiders crawl frequency
(2), in Shanghai to search the URL page, click on the snapshot in Shanghai love, find love Shanghai not updated snapshot snapshot date, directly into the page, the spider has little to grab this page.
you will find that when you search for a keyword in the love of Shanghai, in a short period of time, the search results are the same, this is because cache mechanism. But after a period of time, then go to the search keywords, the search results will have some changes, this is because the cache and cache out with the new mechanism will be involved in the whole search engine mechanism.
2, a cache mechanism concept: