Fixed #7732 -- Added support for connection pools on Oracle.

3 files changed, 80 insertions, 6 deletions

diff --git a/django/db/backends/oracle/base.py b/django/db/backends/oracle/base.py
index df78d9ba27..3b37c38f97 100644
--- a/django/db/backends/oracle/base.py
+++ b/django/db/backends/oracle/base.py
@@ -14,6 +14,7 @@ from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.db import IntegrityError
 from django.db.backends.base.base import BaseDatabaseWrapper
+from django.db.backends.oracle.oracledb_any import is_oracledb
 from django.db.backends.utils import debug_transaction
 from django.utils.asyncio import async_unsafe
 from django.utils.encoding import force_bytes, force_str
@@ -235,6 +236,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
     introspection_class = DatabaseIntrospection
     ops_class = DatabaseOperations
     validation_class = DatabaseValidation
+    _connection_pools = {}
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -243,10 +245,52 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         )
         self.features.can_return_columns_from_insert = use_returning_into
 
+    @property
+    def is_pool(self):
+        return self.settings_dict["OPTIONS"].get("pool", False)
+
+    @property
+    def pool(self):
+        if not self.is_pool:
+            return None
+
+        if self.settings_dict.get("CONN_MAX_AGE", 0) != 0:
+            raise ImproperlyConfigured(
+                "Pooling doesn't support persistent connections."
+            )
+
+        pool_key = (self.alias, self.settings_dict["USER"])
+        if pool_key not in self._connection_pools:
+            connect_kwargs = self.get_connection_params()
+            pool_options = connect_kwargs.pop("pool")
+            if pool_options is not True:
+                connect_kwargs.update(pool_options)
+
+            pool = Database.create_pool(
+                user=self.settings_dict["USER"],
+                password=self.settings_dict["PASSWORD"],
+                dsn=dsn(self.settings_dict),
+                **connect_kwargs,
+            )
+            self._connection_pools.setdefault(pool_key, pool)
+
+        return self._connection_pools[pool_key]
+
+    def close_pool(self):
+        if self.pool:
+            self.pool.close(force=True)
+            pool_key = (self.alias, self.settings_dict["USER"])
+            del self._connection_pools[pool_key]
+
     def get_database_version(self):
         return self.oracle_version
 
     def get_connection_params(self):
+        # Pooling feature is only supported for oracledb.
+        if self.is_pool and not is_oracledb:
+            raise ImproperlyConfigured(
+                "Pooling isn't supported by cx_Oracle. Use python-oracledb instead."
+            )
         conn_params = self.settings_dict["OPTIONS"].copy()
         if "use_returning_into" in conn_params:
             del conn_params["use_returning_into"]
@@ -254,6 +298,8 @@ class DatabaseWrapper(BaseDatabaseWrapper):
 
     @async_unsafe
     def get_new_connection(self, conn_params):
+        if self.pool:
+            return self.pool.acquire()
         return Database.connect(
             user=self.settings_dict["USER"],
             password=self.settings_dict["PASSWORD"],
@@ -345,6 +391,12 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         else:
             return True
 
+    def close_if_health_check_failed(self):
+        if self.pool:
+            # The pool only returns healthy connections.
+            return
+        return super().close_if_health_check_failed()
+
     @cached_property
     def oracle_version(self):
         with self.temporary_connection():
diff --git a/django/db/backends/oracle/creation.py b/django/db/backends/oracle/creation.py
index b0a5177728..682379930f 100644
--- a/django/db/backends/oracle/creation.py
+++ b/django/db/backends/oracle/creation.py
@@ -205,13 +205,15 @@ class DatabaseCreation(BaseDatabaseCreation):
         Destroy a test database, prompting the user for confirmation if the
         database already exists. Return the name of the test database created.
         """
-        self.connection.settings_dict["USER"] = self.connection.settings_dict[
-            "SAVED_USER"
-        ]
-        self.connection.settings_dict["PASSWORD"] = self.connection.settings_dict[
-            "SAVED_PASSWORD"
-        ]
+        if not self.connection.is_pool:
+            self.connection.settings_dict["USER"] = self.connection.settings_dict[
+                "SAVED_USER"
+            ]
+            self.connection.settings_dict["PASSWORD"] = self.connection.settings_dict[
+                "SAVED_PASSWORD"
+            ]
         self.connection.close()
+        self.connection.close_pool()
         parameters = self._get_test_db_params()
         with self._maindb_connection.cursor() as cursor:
             if self._test_user_create():
@@ -223,6 +225,7 @@ class DatabaseCreation(BaseDatabaseCreation):
                     self.log("Destroying test database tables...")
                 self._execute_test_db_destruction(cursor, parameters, verbosity)
         self._maindb_connection.close()
+        self._maindb_connection.close_pool()
 
     def _execute_test_db_creation(self, cursor, parameters, verbosity, keepdb=False):
         if verbosity >= 2:
diff --git a/django/db/backends/oracle/features.py b/django/db/backends/oracle/features.py
index 72c6180f50..ad9ab8da55 100644
--- a/django/db/backends/oracle/features.py
+++ b/django/db/backends/oracle/features.py
@@ -139,6 +139,25 @@ class DatabaseFeatures(BaseDatabaseFeatures):
                     },
                 }
             )
+        if self.connection.is_pool:
+            skips.update(
+                {
+                    "Pooling does not support persistent connections": {
+                        "backends.base.test_base.ConnectionHealthChecksTests."
+                        "test_health_checks_enabled",
+                        "backends.base.test_base.ConnectionHealthChecksTests."
+                        "test_health_checks_enabled_errors_occurred",
+                        "backends.base.test_base.ConnectionHealthChecksTests."
+                        "test_health_checks_disabled",
+                        "backends.base.test_base.ConnectionHealthChecksTests."
+                        "test_set_autocommit_health_checks_enabled",
+                        "servers.tests.LiveServerTestCloseConnectionTest."
+                        "test_closes_connections",
+                        "backends.oracle.tests.TransactionalTests."
+                        "test_password_with_at_sign",
+                    },
+                }
+            )
         if is_oracledb and self.connection.oracledb_version >= (2, 1, 2):
             skips.update(
                 {