When all values of a field with a db_default are DatabaseDefault, which
is the case most of the time, there is no point in specifying explicit
DEFAULT for all INSERT VALUES as that's what the database will do anyway
if not specified.
In the case of PostgreSQL doing so can even be harmful as it prevents
the usage of the UNNEST strategy and in the case of Oracle, which
doesn't support the usage of the DEFAULT keyword, it unnecessarily
requires providing literal db defaults.
Thanks Lily Foote for the review.
This should make bulk_create significantly faster on Postgres when provided
only literal values.
Thanks James Sewell for writing about this technique, Tom Forbes for
validating the performance benefits, David Sanders and Mariusz Felisiak
for the review.
Following the addition of PostgreSQL connection pool support in
Refs #33497, the methods for configuring the database role and timezone
were moved to module-level functions. This change prevented subclasses
of DatabaseWrapper from overriding these methods as needed, for example,
when creating wrappers for other PostgreSQL-based backends.
Thank you Christian Hardenberg for the report and to
Florian Apolloner and Natalia Bidart for the review.
Regression in fad334e1a9b54ea1acb8cce02a25934c5acfe99f.
Co-authored-by: Natalia <124304+nessita@users.noreply.github.com>
While we provide a `cursor_factory` based on the value of the
`server_side_bindings` option to `psycopg.Connection` it is ignored by
the `cursor` method when `name` is specified for `QuerySet.iterator()`
usage and it causes the usage of `psycopg.ServerCursor` which performs
server-side bindings.
Since the ORM doesn't generates SQL that is suitable for server-side
bindings when dealing with parametrized expressions a specialized cursor
must be used to allow server-side cursors to be used with client-side
bindings.
Thanks Richard Ebeling for the report.
Thanks Florian Apolloner and Daniele Varrazzo for reviews.
Thanks Simon Charette, Tim Graham, and Adam Johnson for reviews.
Co-authored-by: Florian Apolloner <florian@apolloner.eu>
Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>
- Used connection.info instead of connection.get_parameter_status() and
connection.server_info which don't exist in psycopg 3.
- Set encoding using the client_encoding connection parameter instead
of connection.set_client_encoding() that doesn't exist in psycopg 3.
- Used the dbname connection parameter instead of deprecated
alias - database.
The sql_flush() positional argument sequences is replaced by the boolean
keyword-only argument reset_sequences. This ensures that the old
function signature can't be used by mistake when upgrading Django. When
the new argument is True, the sequences of the truncated tables will
reset. Using a single boolean value, rather than a list, allows making a
binary yes/no choice as to whether to reset all sequences rather than a
working on a completely different set.
