Tiny optimisation: increase the cache size from 100 to 128

Author: Erlend E. Aasland

Doc/library/sqlite3.rst

@@ -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

Doc/whatsnew/3.10.rst

@@ -1231,10 +1231,10 @@ Add audit events for :func:`~sqlite3.connect/handle`,
 :meth:`~sqlite3.Connection.load_extension`.
 (Contributed by Erlend E. Aasland in :issue:`43762`.)
 
-
 :mod:`sqlite3` now utilizes :meth:`functools.lru_cache` to implement the
 connection statement cache. The statement cache can be accessed via the new
-method :meth:`sqlite3.Connection.statement_cache`.
+method :meth:`sqlite3.Connection.statement_cache`. As a small optimisation, the
+default statement cache size has been increased from 100 to 128.
 (Contributed by Erlend E. Aasland in :issue:`42862`.)
 
 sys

Lib/sqlite3/test/dbapi.py

@@ -207,11 +207,11 @@ def test_statement_cache(self):
         info = cache.cache_info()
         self.assertEqual(info.hits, 1)
         self.assertEqual(info.misses, 1)
-        self.assertEqual(info.maxsize, 100)
+        self.assertEqual(info.maxsize, 128)
         self.assertEqual(info.currsize, 1)
 
     def test_statement_cache_maxsize(self):
-        maxsize = 5
+        maxsize = 8
         testsize = maxsize + 1
         cx = sqlite.connect(':memory:', cached_statements=maxsize)
         for i in range(testsize):

Misc/NEWS.d/next/Library/2021-01-13-00-02-44.bpo-42862.Z6ACLN.rst

@@ -1,4 +1,5 @@
 :mod:`sqlite3` now utilizes :meth:`functools.lru_cache` to implement the
 connection statement cache. The statement cache can be accessed via the new
-method :meth:`sqlite3.Connection.statement_cache`. Patch by Erlend E.
-Aasland.
+method :meth:`sqlite3.Connection.statement_cache`. As a small optimisation, the
+default statement cache size has been increased from 100 to 128.
+Patch by Erlend E. Aasland.

Modules/_sqlite/connection.c

@@ -105,7 +105,7 @@ pysqlite_connection_init(pysqlite_Connection *self, PyObject *args,
     PyObject* isolation_level = NULL;
     PyObject* factory = NULL;
     int check_same_thread = 1;
-    int cached_statements = 100;
+    int cached_statements = 128;
     int uri = 0;
     double timeout = 5.0;
     int rc;