Any upgrade impact in changing max length of existing column?

[Usha Sri Ramidi]

Hi Team,

We have a requirement  to do the following:

1. Increase  the max length on existing columns. 

Couple of queries before making the above change.

1.  I verified we have many columns of string type with max length > 4000 in servicecnow tables currently. However, on oracle instances any string > 4000 characters should be of CLOB type. Do we need to consider this before  increase length > 4000?  As per documentation for string type field on oracle instances with > 4000char ( https://docs.servicenow.com/bundle/london-platform-administration/page/administer/reference-pages/reference/r_FieldTypes.html) , it will be taken care later by logging an incident with support. So can we go ahead and  define max length to around 13000 with String type?

2. Do we see any upgrade impact with the increase in max length of existing columns?

3. What exactly happens  when the column max length changes during upgrade? How exactly is upgrade of  table data handled in service now? 

Can someone provide your inputs on above queries. Thanks in advance!

-Usha.

[Alikutty A]

#1 You may not be able to do it on an existing field

#2 It is a simple thing to do and you dont need to worry on it. If at all the OOB field was modified and SN has upgraded it, then you need to look into the Skipped records and review it once as part of your next upgrade process.

[Usha Sri Ramidi]

#2. So only on OOB columns manual upgradation of skipped records is required. For other columns there is no impact on upgrade process and its taken care automatically. Can you please confirm.

[Alikutty A]

Yes there is no impact to the custom columns created by you, It will impact only OOB columns which could be handled by skipped review.

If you queries have been answered, request you to mark my response as correct.

Thanks

[Usha Sri Ramidi]

Thanks Alikutty and Rahul!