Often we need to amend our schema, it is tempting to use
drop_table, rename_column and drop_column to amned schema
trouble though is that existing code that is running in production
can depend on the existance of previous schema leading to application
breaking until new code base is deployed.
The commit enforces new rules to ensure we can never drop tables or
columns in migrations and instead use Migration::ColumnDropper and
Migration::TableDropper to defer drop the db objects
This feature can be enabled by choosing a destination for the
`shared drafts category` site setting.
* Staff members can create shared drafts, choosing a destination
category for the topic when it is published.
* Shared Drafts can be viewed in their category, or above the
topic list for the destination category where it will end up.
* When the shared draft is ready, it can be published to the
appropriate category by clicking a button on the topic view.
* When published, Drafts change their timestamps to the current
time, and any edits to the original post are removed.
* Use a EmailValidator.email_regexp for `Email.is_valid?`
check as we're seeing an increase in allocation when
parsing email addresses wih `Mail::Address`.
Why? Some edits by staff are not tracked. For example, during the grace
period, or via the flags/silence dialog.
If a staff member is editing someone else's post, it now goes into the
Staff Action Logs so it can be audited by other staff members.
* Since we can no longer restore into a different schema,
we will move tables in the public schema into the backup schema
first before restoring the dump file which goes into the public
schema. The downside to this approach is that we will increase
the downtime experienced during the restore process. Downtime
would equal the duration of restoring the dump file.
* In `pg_dump` 10.3+ and 9.5.12+, in
it does a `SELECT pg_catalog.set_config('search_path', '', false)`
which changes the state of the current connection. This is known
to be problematic with Pgbouncer which reuses connections. As such,
we'll always try to connect directly to PG directly during
the backup/restore process.
We trust staff + tl2 and up to perform edits in grace period.
Allow them significantly more edit room in grace period prior to storing
a revision.
editing_grace_period_max_diff_high_trust applies to users with tl2 and up.
So
tl0 / 1 : we store an extra revision if more than 100 chars change
tl2 and up : we store an extra revision if more than 400 chars change
We may tweak these numbers as we go.
If a user performs a substantive edit of 20 chars or more during grace period
we will store a revision to track the change
This allows for better auditing of changes that happen during the grace period