python · pablogsal · Jun 3, 2021 · Dec 26, 2020 · Jan 12, 2021 · Jan 12, 2021
@@ -213,7 +213,7 @@ Module functions and constants
    The :mod:`sqlite3` module internally uses a statement cache to avoid SQL parsing
    overhead. If you want to explicitly set the number of statements that are cached
    for the connection, you can set the *cached_statements* parameter. The currently
-   implemented default is to cache 100 statements.
+   implemented default is to cache 128 statements.
 
    If *uri* is true, *database* is interpreted as a URI. This allows you
    to specify options. For example, to open a database in read-only mode

diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
@@ -25,6 +25,7 @@
 import sqlite3 as sqlite
 import sys
 
+from test.support import gc_collect
 from test.support.os_helper import TESTFN, unlink
 
 
@@ -181,6 +182,11 @@ def __fspath__(self):
         with sqlite.connect(path) as cx:
             cx.execute('create table test(id integer)')
 
+        # bpo-42862: addCleanup fails to unlink TESTFN on Windows unless we
+        # explicitly close the connection and run the GC.
+        cx.close()
+        gc_collect()
+
     def test_open_uri(self):
         self.addCleanup(unlink, TESTFN)
         with sqlite.connect(TESTFN) as cx:
@@ -191,6 +197,11 @@ def test_open_uri(self):
             with self.assertRaises(sqlite.OperationalError):
                 cx.execute('insert into test(id) values(1)')
 
+        # bpo-42862: addCleanup fails to unlink TESTFN on Windows unless we
+        # explicitly close the connection and run the GC.
+        cx.close()
+        gc_collect()
+
 
 class CursorTests(unittest.TestCase):
     def setUp(self):

diff --git a/Lib/sqlite3/test/hooks.py b/Lib/sqlite3/test/hooks.py
@@ -23,6 +23,7 @@
 import unittest
 import sqlite3 as sqlite
 
+from test.support import gc_collect
 from test.support.os_helper import TESTFN, unlink
 
 
@@ -261,6 +262,12 @@ def trace(statement):
         cur.execute(queries[1])
         self.assertEqual(traced_statements, queries)
 
+        # bpo-42862: addCleanup fails to unlink TESTFN on Windows unless we
+        # explicitly close the connections and run the GC.
+        con1.close()
+        con2.close()
+        gc_collect()
+
 
 def suite():
     tests = [

diff --git a/Misc/NEWS.d/next/Library/2021-01-13-00-02-44.bpo-42862.Z6ACLN.rst b/Misc/NEWS.d/next/Library/2021-01-13-00-02-44.bpo-42862.Z6ACLN.rst
@@ -0,0 +1,4 @@
+:mod:`sqlite3` now utilizes :meth:`functools.lru_cache` to implement the
+connection statement cache. As a small optimisation, the default
+statement cache size has been increased from 100 to 128.
+Patch by Erlend E. Aasland.