1.1.6

Released: February 28, 2017

orm

• [orm] [bug] Addressed some long unattended performance concerns within the joined
  eager loader query construction system that have accumulated since
  earlier versions as a result of increased abstraction. The use of ad-
  hoc AliasedClass objects per query, which produces lots of
  column lookup overhead each time, has been replaced with a cached
  approach that makes use of a small pool of AliasedClass
  objects that are reused between invocations of joined eager loading.
  Some mechanics involving eager join path construction have also been
  optimized. Callcounts for an end-to-end query construction + single
  row fetch test with a worst-case joined loader scenario have been
  reduced by about 60% vs. 1.1.5 and 42% vs. that of 0.8.6.

  References: #3915

• [orm] [bug] Fixed a major inefficiency in the "eager_defaults" feature whereby
  an unnecessary SELECT would be emitted for column values where the
  ORM had explicitly inserted NULL, corresponding to attributes that
  were unset on the object but did not have any server default
  specified, as well as expired attributes on update that nevertheless
  had no server onupdate set up. As these columns are not part of the
  RETURNING that eager_defaults tries to use, they should not be
  post-SELECTed either.

  References: #3909

• [orm] [bug] Fixed two closely related bugs involving the mapper eager_defaults
  flag in conjunction with single-table inheritance; one where the
  eager defaults logic would inadvertently try to access a column
  that's part of the mapper's "exclude_properties" list (used by
  Declarative with single table inheritance) during the eager defaults
  fetch, and the other where the full load of the row in order to
  fetch the defaults would fail to use the correct inheriting mapper.

  References: #3908

• [orm] [bug] Fixed bug first introduced in 0.9.7 as a result of #3106
  which would cause an incorrect query in some forms of multi-level
  subqueryload against aliased entities, with an unnecessary extra
  FROM entity in the innermost subquery.

  References: #3893

orm declarative

• [bug] [declarative] [orm] Fixed bug where the "automatic exclude" feature of declarative that
  ensures a column local to a single table inheritance subclass does
  not appear as an attribute on other derivations of the base would
  not take effect for multiple levels of subclassing from the base.

  References: #3895

sql

• [sql] [bug] Fixed bug whereby the DDLEvents.column_reflect() event would not
  allow a non-textual expression to be passed as the value of the
  "default" for the new column, such as a FetchedValue
  object to indicate a generic triggered default or a
  sql.expression.text() construct. Clarified the documentation
  in this regard as well.

  References: #3905

postgresql

• [postgresql] [bug] Added regular expressions for the "IMPORT FOREIGN SCHEMA",
  "REFRESH MATERIALIZED VIEW" PostgreSQL statements so that they
  autocommit when invoked via a connection or engine without
  an explicit transaction. Pull requests courtesy Frazer McLean
  and Paweł Stiasny.

  References: #3804

• [postgresql] [bug] Fixed bug in PostgreSQL ExcludeConstraint where the
  "whereclause" and "using" parameters would not be copied during an
  operation like Table.tometadata().

  References: #3900

mysql

• [mysql] [bug] Added new MySQL 8.0 reserved words to the MySQL dialect for proper
  quoting. Pull request courtesy Hanno Schlichting.

mssql

• [mssql] [bug] Added a version check to the "get_isolation_level" feature, which is
  invoked upon first connect, so that it skips for SQL Server version
  2000, as the necessary system view is not available prior to SQL Server
  2005.

  References: #3898

misc

• [bug] [ext] Fixed bug in new sqlalchemy.ext.indexable extension
  where setting of a property that itself refers to another property
  would fail.

  References: #3901

• [ext] [feature] Added baked.Result.scalar() and baked.Result.count()
  to the "baked" query system.

  References: #3896