Change-Id: I23a6abb26bbbe3d118887d043ce761fc4572d8d2
Fixes: #3766

Change-Id: Ied4245433d0d7b469dae6e7394c4931d8405f387

This modifies the Oracle ROWNUM limit/offset approach
to accommodate for the "OF" clause in a "FOR UPDATE"
phrase.  The column expressions must be added to the selected
subquery if necessary and adapted on the outside.

Change-Id: Ia71b5fc4df6d326e73863f8ae9f96e8f1a5acfc1
Fixes: #3741

Some of the dialect impl memoization for TypeDecorator
necessarily keeps the top-level TypeDecorator type
around, since a user-defined type will have bind and result
set processing behavior.  For both TypeDecorator and Variant,
PG dialect needs to ensure it's looking at the SQLAlchemy
type to check for SmallInteger / BigInteger.

Fixes: 3739
Change-Id: I2d45fb997f17c6272d6bb826a77d2dba665adae7
(cherry picked from commit 421fa6b8bf9f0c3c5041579c89ec405ce0f5e0b0)

Rolled back the validation rules a bit in :class:`.Enum` to allow
unknown string values to pass through, unless the flag
``validate_string=True`` is passed to the Enum; any other kind of object is
still of course rejected.  While the immediate use
is to allow comparisons to enums with LIKE, the fact that this
use exists indicates there may be more unknown-string-comparsion use
cases than we expected, which hints that perhaps there are some
unknown string-INSERT cases too.

Change-Id: I7d1d79b374a7d47966d410998f77cd19294ab7b0
Fixes: #3725

Fixes: #3529
Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Change-Id: Ie3bf6ad70d9be9f0e44938830e922db03573991a
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/258

count() here is misleading in that it not only
counts from an arbitrary column in the table, it also
does not make accommodations for DISTINCT, JOIN, etc.
as the ORM-level function does.  Core should not be
attempting to provide a function like this.

Change-Id: I9916fc51ef744389a92c54660ab08e9695b8afc2
Fixes: #3724

Also adds version detection so that DROP INDEX CONCURRENTLY
only renders if the Postgresql version is 9.2 or higher;
for CREATE INDEX CONCURRENTLY, version detection is added
to allow the phrase to omit if the Postgresql version is
less than 8.2.

Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Change-Id: I597287e0ebbbe256c957a3579b58ace6848ab4f4
Pull-request: https://bitbucket.org/zzzeek/sqlalchemy/pull-requests/84