1

We have one table like:

Table Name:

random_number_series

Its columns are as below:

number      [numeric(10)]
name        [varchar(10)]
status      [tinyint(1)]
type        [tinyint(1)]
createdDate [datetime]

This table have around 250-300 million rows.

Now our requirement is that we will generate random numbers in big quantity i.e. 1 million. We want to check that this generated numbers are there in above table (with number column) or not.

How best we can do this?

Note:

-> Random numbers will be generated in application logic.

-> I want to know strategy / pseudocode how best we can design?

  • What will you do when you find some are present? Or do you need to add exactly 1M; that is, you need to "keep trying" until you find enough new numbers? Or something else? – Rick James Nov 12 '16 at 4:26
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Put the million numbers in a table. Then JOIN the tables together to see which ones exist. Or LEFT JOIN ... IS NULL to see which are missing.

  • Yes this one is in mind, will try this one as well. thanks. – murtaza.webdev Nov 12 '16 at 7:10
0

Is your random_number_series table fairly static? Is the number sequence fairly fragmented?

If yes to both, my first thought was that it may be more efficient to store a "Gaps" table in your sequence.

random_number_series_gaps ( gap_start_number , gap_end_number )

If exists 
(
select * from random_number_series_gaps
where @randomNumberFromMyApp between gap_start_number and gap_end_number
)
SELECT 'Random number does not exist!'
  • maintaining gaps table is not seems feasible. – murtaza.webdev Nov 12 '16 at 7:11

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