Caused at a45363a2.

When `group` is used in combination with any calculation method, the
resulting hash uses the grouping expression as the key. Currently we're
incorrectly always favoring the type reported by the query, instead of
the type known by the class. This causes differing behavior depending on
whether the adaptor actually gives proper types with the query or not.
After this change, the behavior will be the same on all adaptors -- we
see if we know the type from the class, fall back to the type from the
query, and finally fall back to the identity type.

Fixes #25595

- Cleanup Active Record CHANGELOG.
- Add missing CHANGELOG for https://github.com/rails/rails/pull/25688.
- Clarify that assets requests logging is suppressed.

The documentation states that parameter values longer than 20 characters
will be truncated by words, but the example shows that a parameter based
on "David Heinemeier Hansson" (with id: 125) becomes "125-david" when
"David Heinemeier".length == 16 so why so short?

The answer lies in the use of the #truncate option omission: nil which
seems to have been intended to mean "nothing", but which actually causes
the default string "..." to be used. This causes #truncate to cleave
words until the "..." can be added and still remain within the requested
size of 20 characters.

The better option is omission: '' (which is probably what was originally
intended).

Furthermore, since the use of #parameterize will remove non-alphanumeric
characters, we can maximize the useful content of the output by calling
parameterize first and then giving truncate a separator: /-/ rather than
a space.

This includes minor grammar fixes throughout the file.

This way, we aren't racing other threads, so we don't need to re-check
the conditional. And we no longer need to hold the lock while calling
remove (which can choose to make a new connection while we wait).

A concurrent thread may have also detected it to be stale, and already
released (or even reassigned) it by now.

Fixes #25585

A thread can only release a connection if it owns it, or it's owned by a
thread that has died.

This nested if checked the same value as the containing case statement.
Moved the code in the if/else into when/else in the containing case.

The current error message only indicates that a touch can fail because the record is new. In practice, we saw cases where touches were failing because the record had been destroyed. `persisted?` checks `new_record?` *and* `destroyed?`. It was confusing to get a message about a new record when in reality we were destroying records.

I also included a helpful tip for users to consider using `persisted?`, `new_record?`, or `destroyed?` before touching.

     as this can lead to confusing time stubbing.

     Instead of:

         travel_to 2.days.from_now do
           # 2 days from today
           travel_to 3.days.from_now do
             # 5 days from today
           end
         end

     preferred way to achieve above is:

         travel_to 2.days.from_now
         # 2 days from today

         travel_back
         travel_to 5.days.from_now
         # 5 days from today

Closes #24690
Fixes #24689

`create_table_info_cache` is used for sharing `create_table_info` both
`table_options` and `foreign_keys`. But `foreign_keys` no longer uses
`create_table_info_cache` by #25307. No need caching anymore.

This reverts commit 407e0ab5.

If you had a foreign key set and then decided to add `on_delete:
:cascade` later in another migration that migration would run but
wouldn't refresh the schema dump.

The reason for this was because `create_table_info` caches the statement
and sets it to be the same as the original declaration for the foreign
key (without the `on_delete: :cascade`.

PR #25307 ended up fixing this bug because it removes the check for
`create_table_info` and relies on reading from `information_schema`. The
fix however was intended to patch another bug. The reason this fixes the
issue is we're no longer parsing the regex from the cached
`create_table_info`.

This regression test is to ensure that the issue does not return if we
for some reason go back to using `create_table_info` to set the foreign
keys.

Because causing an extra query by `sql_for_insert` for guessing a
primary key.
https://github.com/rails/rails/blob/v5.0.0/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb#L121-L125

Do not specal case inspecting associated arrays of over 10 elements, preventing infinite looping in some cases.

Right now with this middleware we are likely always connected, but I'm
hoping to change that soon. This is an easy change to pull out on its
own.

This method appears to have been partially used in connection pool
caching, but it was introduced without much reasoning or any tests. One
edge case test was added later on, but it was focused on implementation
details. This method is no longer used outside of tests, and as such is
removed.

This was added at c7c3f73f but it never raised because MySQL cannot
create text/blob columns with a default value.

As mentioned in 7b86ea67, this is an
internal class.

[ci skip]

r? @sgrif

This reverts commit 7ea502ae, per
internal discussion with @sgrif -- this is documenting the
implementation of a class that isn't intended to be public API.

If you only want the last element of a result set, there's no need to create all
of hash_rows. Also, add a test.

The implementation from abstract/database_statements.rb seems to work just fine.
And with ActiveRecord::Result now implementing an optimized #first method, the
performance concerns previously addressed in
https://github.com/rails/rails/commit/bf79aa4fc14aeb2646331e767038acf0b77e9e7f
should not be an issue.

When you only need the first element of a result set, you shouldn't need to
instantiate all of hash_rows.

- `with_exclusive_scope` was removed in this commit d242e467

I think these are meant to be in the root directory, not in
`/activerecord`? 😬

r? @sgrif

[ci skip]

Currently `Type::Date#serialize` does not cast a value to a date object.
It should be cast to a date object for finding by date column correctly
working.

Fixes #25354.