Hello there,
Current default max length for title field in tickets is 255. That's maximum value that most DB engines allow for a simple text field (varchar). It's ill-advised to increase this limit, if only because it will make the tables more cluttered and break the overall scheme for how tickets should be used. There's "Description" field in tickets, it's also displayed in tooltip whenever you hover your mouse cursor over ticket title field. That field is virtually unlimited in length, but in case you need to add really big description/log to a ticket, you can always use notes.
With all that being said, if you really need to have title field much longer than 255 characters, you need to do two things:
1. Alter table premium_tickets_data_1, change field f_title from VARCHAR(255) to TEXT
2. In table premum_tickets_field, for the row with field "Title", set "param" to desired length (1000?)
Kind regards,
Arek