[Solved] How to perform select on a massive dataset of 10 billion+ rows
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How to perform select on a massive dataset of 10 billion+ rows

When a user registers, email must be unique, and the registration check must take 1 second at most.

How does Facebook / Google manage to perform a select on table with several billion rows, retrieving instant response.

Is it as simple as:

select email from users where email = "[email protected]" limit 1

Does having an index on email field and running this query on a super fast server do the trick?

Or is there more to it?

How to optimize this SQL query?

The following recommendations will help you in your SQL tuning process.
You'll find 3 sections below:

  1. Description of the steps you can take to speed up the query.
  2. The optimal indexes for this query, which you can copy and create in your database.
  3. An automatically re-written query you can copy and execute in your database.
The optimization process and recommendations:
  1. Create Optimal Indexes (modified query below): The recommended indexes are an integral part of this optimization effort and should be created before testing the execution duration of the optimized query.
Optimal indexes for this query:
ALTER TABLE `users` ADD INDEX `users_idx_email_zzz` (`email`,`zzz`);
The optimized query:
SELECT
        users.email 
    FROM
        users 
    WHERE
        users.email = users."[email protected]" LIMIT 1

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* original question posted on StackOverflow here.