From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Fri, 30 May 2008 20:56:47 +0000 (+0000)
Subject: - Cursors now have "arraysize" set to 50 by default on
X-Git-Tag: rel_0_4_7~25
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=062324bd2c2c952417edcd10a7c98a1ae7dc77c6;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

- Cursors now have "arraysize" set to 50 by default on
them, the value of which is configurable using the
"arraysize" argument to create_engine() with the
Oracle dialect.  This to account for cx_oracle's default
setting of "1", which has the effect of many round trips
being sent to Oracle.  This actually works well in
conjunction with BLOB/CLOB-bound cursors, of which
there are any number available but only for the life of
that row request (so BufferedColumnRow is still needed,
but less so). [ticket:1062]
---

diff --git a/CHANGES b/CHANGES
index 3fa0e047ac..581ffce437 100644
--- a/CHANGES
+++ b/CHANGES
@@ -17,6 +17,17 @@ CHANGES
       in other owner namespaces with the same name do not
       conflict. [ticket:709]
 
+    - Cursors now have "arraysize" set to 50 by default on 
+      them, the value of which is configurable using the 
+      "arraysize" argument to create_engine() with the
+      Oracle dialect.  This to account for cx_oracle's default 
+      setting of "1", which has the effect of many round trips 
+      being sent to Oracle.  This actually works well in 
+      conjunction with BLOB/CLOB-bound cursors, of which 
+      there are any number available but only for the life of 
+      that row request (so BufferedColumnRow is still needed, 
+      but less so). [ticket:1062]
+
 
 0.4.6
 =====
diff --git a/lib/sqlalchemy/databases/oracle.py b/lib/sqlalchemy/databases/oracle.py
index d295aab666..4cbbaa9c56 100644
--- a/lib/sqlalchemy/databases/oracle.py
+++ b/lib/sqlalchemy/databases/oracle.py
@@ -213,6 +213,12 @@ class OracleExecutionContext(default.DefaultExecutionContext):
                     self.out_parameters[name] = self.cursor.var(dbtype)
                     self.parameters[0][name] = self.out_parameters[name]
 
+    def create_cursor(self):
+        c = self._connection.connection.cursor()
+        if self.dialect.arraysize:
+            c.cursor.arraysize = self.dialect.arraysize
+        return c
+
     def get_result_proxy(self):
         if hasattr(self, 'out_parameters'):
             if self.compiled_parameters is not None and len(self.compiled_parameters) == 1:
@@ -242,10 +248,11 @@ class OracleDialect(default.DefaultDialect):
     supports_pk_autoincrement = False
     default_paramstyle = 'named'
 
-    def __init__(self, use_ansi=True, auto_setinputsizes=True, auto_convert_lobs=True, threaded=True, allow_twophase=True, **kwargs):
+    def __init__(self, use_ansi=True, auto_setinputsizes=True, auto_convert_lobs=True, threaded=True, allow_twophase=True, arraysize=50, **kwargs):
         default.DefaultDialect.__init__(self, **kwargs)
         self.use_ansi = use_ansi
         self.threaded = threaded
+        self.arraysize = arraysize
         self.allow_twophase = allow_twophase
         self.supports_timestamp = self.dbapi is None or hasattr(self.dbapi, 'TIMESTAMP' )
         self.auto_setinputsizes = auto_setinputsizes
diff --git a/test/dialect/oracle.py b/test/dialect/oracle.py
index 829c189786..a6eb9e4967 100644
--- a/test/dialect/oracle.py
+++ b/test/dialect/oracle.py
@@ -3,6 +3,8 @@ from sqlalchemy import *
 from sqlalchemy.sql import table, column
 from sqlalchemy.databases import oracle
 from testlib import *
+from testlib.engines import testing_engine
+import os
 
 
 class OutParamTest(TestBase, AssertsExecutionResults):
@@ -304,6 +306,39 @@ class TypesTest(TestBase, AssertsCompiledSQL):
         finally:
             testing.db.execute("DROP TABLE Z_TEST")
 
+class BufferedColumnTest(TestBase, AssertsCompiledSQL):
+    __only_on__ = 'oracle'
+
+    def setUpAll(self):
+        global binary_table, stream, meta
+        meta = MetaData(testing.db)
+        binary_table = Table('binary_table', meta, 
+           Column('id', Integer, primary_key=True),
+           Column('data', Binary)
+        )
+        meta.create_all()
+        stream = os.path.join(os.path.dirname(testenv.__file__), 'binary_data_one.dat')
+        stream = file(stream).read(12000)
+
+        for i in range(1, 11):
+            binary_table.insert().execute(id=i, data=stream)
+
+    def tearDownAll(self):
+        meta.drop_all()
+
+    def test_fetch(self):
+        self.assertEquals(
+            binary_table.select().execute().fetchall() ,
+            [(i, stream) for i in range(1, 11)], 
+        )
+
+    def test_fetch_single_arraysize(self):
+        eng = testing_engine(options={'arraysize':1})
+        self.assertEquals(
+            eng.execute(binary_table.select()).fetchall(),
+            [(i, stream) for i in range(1, 11)], 
+        )
+
 class SequenceTest(TestBase, AssertsCompiledSQL):
     def test_basic(self):
         seq = Sequence("my_seq_no_schema")