instal the new for apple Disk Sorter Ultimate 15.6.18

If you've worked with any serious data volume this can rapidly become expensive. The problem with this method, is that you're still guaranteed a full index scan and then a complete sort of the data.

When someone get's fancy they add that you should really wrap NewID() in CheckSum(), you know, for performance! WHERE u.Id >= is an old question, but one aspect of the discussion is missing, in my opinion - PERFORMANCE. SELECT = ABS((CHECKSUM(NEWID()))) % Get the first row around that ID */ * Get a random number smaller than the table's top ID */ĭECLARE INT = ( SELECT MAX(Id) FROM dbo.Users) For top N rows, call the code below N times or generate N random numbers and use in an IN clause. More on method 3: Get the top ID field in the table, generate a random number, and look for that ID.

Method 4, OFFSET-FETCH (2012+) > Only performs properly with a clustered index.

Method 3, Best but Requires Code: Random Primary Key > Fastest, but won't work for negative numbers.

Method 2, Better but Strange: TABLESAMPLE > Many gotchas & is not really random!.

Method 1, Bad: ORDER BY NEWID() > Bad performance!.

You can read the blog for more details.Ĥ ways to get a random row from a large table:

įrom the above link, I have summarized the methods which you can use to generate a random id. Here is the explanation from Brent Ozar's blog.

So, newId() might be ok in such cases where performance is not too bad & does not have a huge impact. It returns about 10k rows in about 3 seconds. I have an unimportant query which uses newId() and joins many tables.

Instal the new for apple Disk Sorter Ultimate 15.6.18