Max length value of string field is not honoured

Nisar3 · ‎07-02-2025

In the sys_dictionary table, I've the following field:

But ServiceNow is allowing to store a value greater than 30 characters. For eg: It allowed to store a value of "Health and Safety - Customer responsibility" which is 43 characters long.

Is this expected?

SANDEEP DUTTA · ‎07-02-2025

Hi @Nisar3 ,

When you create a new sys_dictionary record to define a new string field, the max_length is mandatory. Despite the similarity of the name to HTML's maxlength attributes for input or textarea tags, this is not enforced as a limit in the client or server.

Max length is not enforced on the Now Platform

Fields in ServiceNow accept string inputs greater than the sys_dictionary max_length value. This is the expected behavior of the product.

When you create a string field in ServiceNow, the underlying column in the database is created with a default data type based in part on the specified max_length value:

Small (40) = varchar(40)
Medium (100) = varchar(100)
Large (1000) = mediumtext
Extra Large (4000) = mediumtext

Refer to below article for more details:

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0685779

Thanks,
Sandeep Dutta

Please mark the answer correct & Helpful, if i could help you.

View solution in original post

SANDEEP DUTTA · ‎07-02-2025

Hi @Nisar3 ,

We do not control database, since ServiceNow is a Saas Platform.

Thanks,
Sandeep Dutta

Please mark the answer correct & Helpful, if i could help you.

Nisar3 · ‎07-02-2025

I understand we cannot control the database. But what I'm trying to figure out is if there is way to know what size would be set in the database if I use max length = 20 in sys_dictionary.

SANDEEP DUTTA · ‎07-02-2025

HI @Nisar3 ,

As per my previous reply, if you use max length = 20 in sys_dictionary then it will be Small (40) = varchar(40).

Thanks,
Sandeep Dutta

Please mark the answer correct & Helpful, if i could help you.

Nisar3 · ‎07-02-2025

Thanks Sandeep for that. I'm still a little confused though. How are you able to come to that conclusion? Is my understanding correct for the following screenshot

If we specify anything less than 40 in dictionary, it will set to varchar(40) at database level
Anything less than 100 (but greater than 40) in dictionary, it will set to varchar(100) at database level
Anything less than 1000 (but greater than 100) in dictionary, it will set to mediumtext at database level and so on..

Is the assumption correct? I would not think so because I've set the value to 30 in dictionary but ServiceNow allowed 43 characters.

SANDEEP DUTTA · ‎07-02-2025

Hi @Nisar3 ,

Yes, your assumption is correct.

Thanks,
Sandeep Dutta

Please mark the answer correct & Helpful, if i could help you.