There are at least two possibilities for increasing metadata field sizes. The request most often heard inquires about increasing the default memo field size (which is originally 255 characters). The second avenue is to increase the size for a single one-off metadata field.
Expanding Default Memo Field Size
We can use a configuration variable within Content Server named "MemoFieldSize" to increase the default size of new memo fields beyond the original limit of 255 characters. Keep in mind this affects memo fields that you create AFTER you add this configuration and restart content server. For fields that have already been created you will also need to go into the database and directly increase the column size for that individual metadata field within the DocMeata table.
If you operate in a database with UTF8 encoding you should keep in mind that this can affect that actual number of characters your users will be able to input. Oracle has a 4000 byte per column limit for varchar2/nvarchar2 data types. Hence, if you set the column to the 4,000 byte maximum and each character takes 3 bytes of space you get roughly 1,333 characters to work with.
So, what to do where, when and how. Log into your content server with administrative privileges and select Admin Server from the Administration menu. Click the button for the instance you will be working with and then select General Configuration from the left hand menu. Add MemoFieldSize=1024 as a new line in the variables list and click save. Restart. Similarly you could go directly to the file system and add this configuration setting to the config.cfg file. Oh, and don’t forget to get out your favorite database manipulation device and increase those columns sizes.
Expanding a Single Field
Great, right, so that’s all nice and what not but I don’t want to increase ALL my memo fields. I only want to increase the size of a single field. Well sure you do, who wouldn’t? In this case you can again use config.cfg or go through the admin server to add xMyMetadatafield:maxLength=1024 or whatever your new field size is meant to be. Again, change the table definition in the database and restart your content server.
First Note: increasing field sizes also more than likely will increase indexing and searching time. More stuff equals more time. Pretty simple, but a reminder of that fact is relevant.
Second Note: I performed these actions on a 10gR3 content server and 11g database with existing content. The field widening did NOT erase my data. Obviously if I were to restrict down the field size instead of widen the field my data would have been truncated.