[issue10740] sqlite3 module breaks transactions and potentially corrupts data
Rian Hunter added the comment: Implicit transactions can also cause mysterious "database is locked" bugs, even when a large timeout is set on the connection. Many, many people are affected by this bug (search the web for "python sqlite database is locked"). The attached code demonstrates this bug and possible (unintuitive) fixes. If there won't be a fix soon, then at least the documentation should note this quirky behavior. -- nosy: +rhunter Added file: http://bugs.python.org/file42249/test_sqlite.py ___ Python tracker <http://bugs.python.org/issue10740> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10740] sqlite3 module breaks transactions and potentially corrupts data
Changes by Rian Hunter : Added file: http://bugs.python.org/file42250/test_sqlite.py ___ Python tracker <http://bugs.python.org/issue10740> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10740] sqlite3 module breaks transactions and potentially corrupts data
Changes by Rian Hunter : Removed file: http://bugs.python.org/file42249/test_sqlite.py ___ Python tracker <http://bugs.python.org/issue10740> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10740] sqlite3 module breaks transactions and potentially corrupts data
Changes by Rian Hunter : Removed file: http://bugs.python.org/file42250/test_sqlite.py ___ Python tracker <http://bugs.python.org/issue10740> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10740] sqlite3 module breaks transactions and potentially corrupts data
Changes by Rian Hunter : Added file: http://bugs.python.org/file42251/test_sqlite.py ___ Python tracker <http://bugs.python.org/issue10740> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10740] sqlite3 module breaks transactions and potentially corrupts data
Rian Hunter added the comment: @mike Yes you're right, This bug report is different, my mistake. DB-API may require implicit transactions but pysqlite should open a transaction before *any* non-DDL statement, including "SELECT", not just DML statements. Currently one must issue a dummy DML statement just to open a transaction that otherwise would start with a SELECT statement. I see nothing in DB-API (https://www.python.org/dev/peps/pep-0249/) that says transactions should implicitly open before DML statements and not SELECT statements. -- ___ Python tracker <http://bugs.python.org/issue10740> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue26625] SELECT-initiated transactions can cause "database is locked" in sqlite
New submission from Rian Hunter: When a transaction starts with a SELECT statement this can invoke a "database is locked" error if the SELECT statement is not exhausted or explicitly closed. This can lead to subtle "database is locked" bugs, even when a large timeout is set on the connection. Many, many people are affected by this bug (search the web for "python sqlite database is locked"). The attached code demonstrates this bug and possible (unintuitive) fixes. The best workaround is to "explicitly" start a transaction in these cases by issuing a dummy DML statement. This seems very clumsy. My proposed fix is to implicitly open a transaction before all non-DDL statements (including SELECT statements), not just DML statements. If there won't be a fix soon, then at least the documentation should note this quirky behavior. -- components: Library (Lib) files: unintuitive_sqlite_behavior.py messages: 262282 nosy: rhunter priority: normal severity: normal status: open title: SELECT-initiated transactions can cause "database is locked" in sqlite type: behavior versions: Python 2.7, Python 3.2, Python 3.3, Python 3.4, Python 3.5, Python 3.6 Added file: http://bugs.python.org/file42259/unintuitive_sqlite_behavior.py ___ Python tracker <http://bugs.python.org/issue26625> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue26625] SELECT-initiated transactions can cause "database is locked" in sqlite
Rian Hunter added the comment: duplicate of #9924 -- resolution: -> duplicate status: open -> closed ___ Python tracker <http://bugs.python.org/issue26625> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9924] sqlite3 SELECT does not BEGIN a transaction, but should according to spec
Changes by Rian Hunter : -- versions: +Python 3.2, Python 3.5, Python 3.6 ___ Python tracker <http://bugs.python.org/issue9924> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9924] sqlite3 SELECT does not BEGIN a transaction, but should according to spec
Rian Hunter added the comment: This bug can also lead to subtle and unintuitive "database is locked" bugs, even when a large timeout is set on the connection. Many, many people are affected by this bug (search the web for "python sqlite database is locked"). I've attached code that demonstrates this issue. I disagree that the current behavior cuts down on SQLite file locking. As soon as any SELECT statement is opened, an implicit lock is held by SQLite (whether it resides within a BEGIN block or not): https://www.sqlite.org/lockingv3.html SQLite has been designed to do its own "late locking." Pysqlite does not need to duplicate this behavior. This is a clear-as-day bug and should be fixed. -- nosy: +rhunter Added file: http://bugs.python.org/file42260/unintuitive_sqlite_behavior.py ___ Python tracker <http://bugs.python.org/issue9924> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue10740] sqlite3 module breaks transactions and potentially corrupts data
Changes by Rian Hunter : -- nosy: -rhunter ___ Python tracker <http://bugs.python.org/issue10740> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
