Unfortunately this is not really large enough. On some research projects it's useful to have larger limits due to links / other metadata that cannot easily be truncated. Can you please facilitate arbitrary control of this amount through the admin config interface or by modifying the database schema?

It seems like this is a locking table which hangs your instance, so it's more than "slow". People should consider it a short outage, right? Maybe the guidance here should specify that?

Also, I have mine now set to

message | character varying(65535)

I restarted Mattermost, but the client is stopping me at 16383 characters.
Is more than 16383 actually not supported?

As of 5.0.0, the maximum post message size is 16383 (multi-byte) characters. If your logs show a number less than this limit and you want to enable longer post messages, you will need to manually migrate your database as described below. This migration can be slow for larger Posts tables, so it’s best to schedule this upgrade during off-peak hours.

To migrate a MySQL database, connect to your database and run the following:

ALTER TABLE Posts MODIFY COLUMN Message TEXT;

To migrate a PostgreSQL database, connect to your database and run the following:

ALTER TABLE Posts ALTER COLUMN Message TYPE VARCHAR(65535);

Restart your Mattermost instances.

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For new installs as of Mattermost 5.0 and later, deployments will have the higher character limit by default.

@Mattermost Admin - What exactly is it that is available in Mattermost 5.0? And is there a feature/flag/config-thing that is needed to enable this? Is there a new (higher) limit now? If so, what is the limit?

Any update on this?

Making the limit configurable will be amazing and I'm willing to implement it.

It definitely does make sense to have a limit, but the limit should be configurable: I can imagine some people would want a lower limit for their usage of Mattermost, and at my work we often find ourselves needing more thank 4000.

While some kind of limit may be useful to prevent manifestos from being posted, 4k chars is extremely limiting when we need to exchange more information, especially source code.

This is a frequent request at my workplace, particularly when users exchange snippets of code or logs.

would be nice to for this feature to also show a preview of the text. for example you could show the first 3-4 lines of the text file instead of "</>" which is currently shown

I have voted and I really need a mechanism which allows me to receive big messages, such as a table with links and other things.

Have the client automatically create text attachments for messages that exceed the 4000 character limit.