Refactor for cx_Oracle version 6oracle_numeric

Drops support for cx_Oracle prior to version 5.x, reworks
numeric and binary support.

Fixes: #4064

Change-Id: Ib9ae9aba430c15cd2a6eeb4e5e3fd8e97b5fe480

1 files changed, 61 insertions, 0 deletions

diff --git a/doc/build/changelog/unreleased_12/oracle_refactor.rst b/doc/build/changelog/unreleased_12/oracle_refactor.rst
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+.. change::
+    :tags: bug, oracle
+    :tickets: 4064
+
+    Partial support for persisting and retrieving the Oracle value
+    "infinity" is implemented with cx_Oracle, using Python float values
+    only, e.g. ``float("inf")``.  Decimal support is not yet fulfilled by
+    the cx_Oracle DBAPI driver.
+
+.. change::
+    :tags: bug, oracle
+
+    The cx_Oracle dialect has been reworked and modernized to take advantage of
+    new patterns that weren't present in the old 4.x series of cx_Oracle. This
+    includes that the minimum cx_Oracle version is the 5.x series and that
+    cx_Oracle 6.x is now fully tested. The most significant change involves
+    type conversions, primarily regarding the numeric / floating point and LOB
+    datatypes, making more effective use of cx_Oracle type handling hooks to
+    simplify how bind parameter and result data is processed.
+
+    .. seealso::
+
+        :ref:`change_cxoracle_12`
+
+.. change::
+    :tags: bug, oracle
+    :tickets: 3997
+
+    two phase support for cx_Oracle has been completely removed for all
+    versions of cx_Oracle, whereas in 1.2.0b1 this change only took effect for
+    the 6.x series of cx_Oracle.  This feature never worked correctly
+    in any version of cx_Oracle and in cx_Oracle 6.x, the API which SQLAlchemy
+    relied upon was removed.
+
+    .. seealso::
+
+        :ref:`change_cxoracle_12`
+
+.. change::
+    :tags: bug, oracle
+
+    The column keys present in a result set when using :meth:`.Insert.returning`
+    with the cx_Oracle backend now use the correct column / label names
+    like that of all other dialects.  Previously, these came out as
+    ``ret_nnn``.
+
+    .. seealso::
+
+        :ref:`change_cxoracle_12`
+
+.. change::
+    :tags: bug, oracle
+
+    Several parameters to the cx_Oracle dialect are now deprecated and will
+    have no effect: ``auto_setinputsizes``, ``exclude_setinputsizes``,
+    ``allow_twophase``.
+
+    .. seealso::
+
+        :ref:`change_cxoracle_12`
+