Max length value of string field is not honoured

[Nisar3]

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 · Accepted solution]

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

[Nisar3]

So what would be the size in database if max length is set to 30 in sys_dictionary? i.e after how many characters will it start truncating data?

[SANDEEP DUTTA]

It would be depending on how the database would create the varchar. For 30 it could be medium which is upto 100.

[Nisar3]

So there's no guide to know what value of max length corresponds to what size in database? What if I want to know the size in database if I set max length to 20 in sys_dictionary? How would I know that?