Home/ Questions/Q 8570021
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-11T18:27:59+00:00

I have a user_info table in five different locations. Now I need to integrate

  • 0

I have a user_info table in five different locations. Now I need to integrate all the rows into a central user_info table. To do this I need a unique id for each row in source tables. Because when all the rows come into the central table, then each user must have a unique ID.

Now my questions are:

  1. if I use uniqueidentifier NEWID() for each source table then is it will be unique for globally & life time or have any chance to be duplicate?

  2. How does SQL Server create the NEWID()? I need to know the key generation structure.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Yes, there is no chance of a duplicate between machines.

    NEWID() is based on a combination of a pseudo random number (from the clock) and the MAC address of the primary NIC.

    However, inserting random numbers like this as the clustered key on a table is terrible for performance. You should consider either NEWSEQUENTIALID() or a COMB-type function for generating GUIDs that still offer the collision-avoidance benefits of NEWID() while still maintaining acceptable INSERT performance.

    • 0