id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
36144	DatabaseOperations.bulk_batch_size() should consider more database limits on SQLite and Oracle	Sarah Boyce	nzioker	"`DatabaseOperations.bulk_batch_size()` is used to calculate the maximum batch size when doing operations such as bulk_update and bulk_create

When investigating the impact of composite primary keys on the maximum batch size calculation for `bulk_update()`, it became clear that there are more database limits that need to be considered when calculating the maximum batch size in order to have a bullet proof solution.

One possible limit in play on SQLite is `SQLITE_MAX_EXPR_DEPTH` which is 1000 (see https://www.sqlite.org/limits.html#max_expr_depth).
On Oracle, we found that a query could error with the ambiguous message: `ORA-00907: missing right parenthesis`, which may be due to hitting some limit (possibly documented here: https://docs.oracle.com/en/database/oracle/oracle-database/23/lnpls/plsql-program-limits.html)

We may need to revisit the API design.

PR discussion: https://github.com/django/django/pull/19088#discussion_r1929940327
Ticket which sparked the discussion/discovery: #36118"	Cleanup/optimization	assigned	Database layer (models, ORM)	5.2	Normal			Simon Charette	Accepted	0	0	0	0	0	0