SEO Series - Steps performed by a search engine

Refer to SEO series here.

In our previous article on SEO, I had mentioned the following:

SEO, or Search Engine Optimization, refers very simple to the strategy and methodology of helping a website rank higher (seen near the top of search engines like Google) on a search return.

What is SEO (search engine optimization)?At its most basic, "SEO" means trying to get your site as high up as possible on search result pages.
This generally means more traffic to your site.
One can define it as a process of trying to make a website appear in a high position when users conduct a search with keywords.

So, to understand SEO, we should first try to understand how do search engines work?I will have more articles on this series soon.

Search engines have two major functions:

• Crawling and indexing documents, articles, images etc
• Return search results with max relevancy and importance (popular)

Steps performed by a search engine (in order):

Crawling:
Simple act of the search engine being able to find your blog and being able to crawl(read) the content.
The tool that does this is known as a spider or crawler.

Indexing:
When a crawler finds your blog, it will try to index the content. This helps it in improving its search while retrieving data for users.

Processing:
Process content and keywords to determine relevancy of the content with respect to the search made.

Relevancy:
Most important aspect where search is considered.
If your blog comes in the first couple of links in google search, you have a high chance of traffic.
Many users never ever go to page 2 in google search at all and hence to get traffic on your page, you need to ensure that your page comes up in the first couple of links in a google search.

Retrieval:
Act of search engine retrieving data for the user.

We will touch upon more aspects of SEO in next articles. 

Refer to SEO series here

B Tree v/s Bit Map Indexes

BitMap v/s B-Tree Index?

If your table has low cardinality value (e.g. Gender column, boolean data), opt for a Bit Map Index.
If your table has high cardinality value, opt for a B-tree Index.

B Tree index is very useful in OLTP systems.
Bit Map works best in Data wareehousing systems.

In Bit Map structures, a two-dimensional array is created with one column for every row in the table being indexed.
Each column represents a distinct value within the bitmapped index.
Thus for low cardinality columns, they become very compact and fast to scan.

In B-tree, records are stored in locations called leaves. The starting point is called the root.
Its a tree where max number of children per node is called order.
Depth is the # of operations needed to reach the desired leaf

Consider below an example of a B-Tree with  

Order   = 2
Depth   = 3
Leaves = 4

                           [Root]
                                |
                                | 
                                |  
                                |  
                               / \  {Node]
                              /   \
                             /     \
                            /\     /\
                           /  \   /  \
                          /    \ /    \
                      [Leaves]