music_library/backlog/tasks/ml-169.6 - Fix-Redundant-stream_insert-immediate-full-reload-after-CRUD.md

id, title, status, assignee, created_date, labels, dependencies, references, modified_files, parent_task_id, priority, ordinal

id	title	status	assignee	created_date	labels	dependencies	references	modified_files	parent_task_id	priority	ordinal
ML-169.6	Fix: Redundant stream_insert + immediate full reload after CRUD	To Do		2026-05-19 11:48	perf fix		backlog/documents/doc-27 - Phase-4-Performance-Audit-Low-Hanging-Fruit-Findings.md	lib/music_library_web/live/scrobble_rules_live/index.ex lib/music_library_web/live/online_store_template_live/index.ex	ML-169	medium	27000

Description

Fix redundant database query pattern where stream_insert is immediately followed by a full load_and_assign_* call that negates the benefit of the incremental insert.

Problem

After a create/save operation, the code performs a correct stream_insert (incremental insert) but then immediately calls load_and_assign_*/2 which does a full stream(..., reset: true) — completely negating the benefit of stream_insert. Same pattern exists for delete operations.

Files

• lib/music_library_web/live/scrobble_rules_live/index.ex:247-253 — handle_info({Form, {:created, ...}) does stream_insert then load_and_assign_rules
• lib/music_library_web/live/online_store_template_live/index.ex:195-201 — handle_info({Form, {:saved, ...}) does stream_insert then load_and_assign_templates

Impact

Wastes a database query after every create/save/delete operation. Medium severity because these are infrequent user actions (not per-keystroke or per-tick).

Fix

Remove the load_and_assign_* call after stream_insert. The stream already has the correct data. For delete, stream_delete already removes the item from the stream — no full reload needed.

Acceptance Criteria

• #1 Creating a scrobble rule inserts it into the stream without a full reload
• #2 Saving an online store template inserts it into the stream without a full reload
• #3 Deleting an item removes it from the stream without a full reload
• #4 Stream order remains correct after insert/delete operations
• #5 No duplicate items appear after create/save