question Re: Is sys_id unique across all the instances globally? in Developer forum

Is sys_id unique across all the instances globally?

Suggy — Thu, 02 May 2024 09:23:49 GMT

I have few questions regarding sys_id.

1. Is sys_id unique per table or unique per instance or unique GLOBALLY across ALL the instances spinned up until now for all the customers world wide?

2. Suppose I create a user record, say its sys_id is "123". Later I will delete the record. Then can ServiceNow generate and use "123" again for new record?

Re: Is sys_id unique across all the instances globally?

Tony Chatfield1 — Wed, 01 May 2024 20:57:40 GMT

Hi, a sys_id is a GUID and so is unique to the instance that it was created in.

Unique record identifier (sys_id) (servicenow.com)

As a unique identifier I would not expect a sys_id to be reused for a different record.

Re: Is sys_id unique across all the instances globally?

Dr Atul G- LNG — Thu, 02 May 2024 08:42:24 GMT

Hi @Suggy

It depends,

if you are following the right way to move your data from Dev - Test - Prod then yes

but if you create instead of migrate ,same record 1st in dev and then in test then sys id will be different.

Re: Is sys_id unique across all the instances globally?

Suggy — Fri, 03 May 2024 12:24:29 GMT

Hi @Tony Chatfield1

So is it UNIQUE across ALL instances world wide?

Re: Is sys_id unique across all the instances globally?

Giles Lewis — Sun, 05 May 2024 11:54:01 GMT

A sys_id is a GUID (Globally Unique Identifier), also known as a UUID (Universally Unique Identifier). The same GUID is never generated twice.

Re: Is sys_id unique across all the instances globally?

Tony Chatfield1 — Sun, 05 May 2024 20:25:55 GMT

A sys_id is unique and so if you generate one in an instance then it is expected that the same sys_id will not be generated by any other instance.

But, the same sys_id's can exists in multiple instances and normally these are default ServiceNow records or from store apps. Any customization you make that is moved to another instance (via update-set or clone) will also result in duplicate sys_id's, but these are always for the same record, with the same content (unless you customize to record).

Re: Is sys_id unique across all the instances globally?

Maddysunil — Mon, 06 May 2024 03:10:21 GMT

@Suggy

In ServiceNow:

Uniqueness of sys_id:
- The sys_id is globally unique across all tables and instances of ServiceNow.
- Each record in a ServiceNow table is identified by a unique sys_id.
- This uniqueness is maintained globally across all instances of ServiceNow, regardless of the customer.
Recycling sys_id:
- Once a record with a specific sys_id, like "123", is deleted, ServiceNow will not reuse that sys_id for a new record.
- ServiceNow does not recycle sys_id values. Even if a record is deleted, its sys_id is not reused for new records.
- This ensures that historical references and relationships within the platform remain intact and consistent.

Please Mark ✅Correct if this solves your query and also mark 👍Helpful if you find my response worthy based on the impact.

Thanks

Re: Is sys_id unique across all the instances globally?

Suggy — Mon, 06 May 2024 15:57:54 GMT

Thanks a lot everyone for your responses !!!