indexing on set-length(10) phone numbers for large number of entries?

I understand that a lot of similar questions have already been asked but i could not find a definitive answer for my question.

In very short,

  • I have to authenticate users using a rest api and using their phone numbers.

  • phone numbers are fixed length (10). can be stored in any way suggested.

  • In a table with thousands of phone numbers and the user_id associated, i wish to be able to query and get the user_id associated with the phone number fast.

  • I read that indexing on strings or random integers is bad.

How should i structure the db to query on phone number most effectively?

Thanks in advance!

Indexing problem [duplicate]

There are hundreds of url on my website https://www.resultsup.in showing status Crawled – currently not indexed and Discovered – Currently not indexed. After submitted several times and waiting for months, these urls still not getting indexed by Google. Content on the site is unique. How to fix this problem.

Crawl and Indexing [closed]

I’m relatively new to blogging, had set up my site, written contents. However, I’m sort of having slight challenges.

  1. Google and Bing aren’t indexing my site categories
  2. Made few adjustments, but google has updated those changes
  3. I want my sitemap menu to display my up today post.

Maybe I’m not doing something right, I did be glad if an SEO expert takes a look at my website

Prevent search engines from indexing specific elements on a site

A website I’m working on has a team section. Every team member has a dedicated site. On the site’s bottom of each team member three other team members are displayed randomly.

Site

What happens here is that search engines index all four images. When I enter the name a specific team member into a search engine I get all four images as results. I want to show only the main image on top. So, how can I prevent search engines from indexing the three images at the bottom?

Non cluster indexing with combination or on single entity for multiple columns

I am new to db design I also read concepts of non cluster indexing and know about the combined non cluster indexing but in my scenario I am having user table with multiple search on column

table column as follows   userName  fatherName  empId  cardNumber and so on. (above all 4 no one column is PK) 

I am having around 50 millions records over here due to large data search take huge time due to that I am thinking to create indexes in table but these all 4 searches are optional means possible user can fill all four or may be one or two of them but I was confused if I make all four separate index and one for all 4 then it might be creating issue on performance of while entering/inserting the data I created even a single index for all 4 column in combined but while I am searching with only card number then it takes huge time shall I created all four separate indexes would this work in combined search of empId and cardNumber

If I created separated once then what about combined searches If I create combinations then indices are 15 which obviously not a good way for insertion… lot of confusion I have can anyone help me thanks in advance