chore: analyze sendportal_subscribers performance

[faridatulna]

Performance Analysis: sendportal_subscribers Table

Overview

This document records the findings of a deep-dive query analysis on the sendportal_subscribers table.
It covers schema/index gaps, slow query patterns, unnecessary queries, and a prioritised improvement plan
with exact file references.

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1. Current Schema & Indexes

Migration: sendportal-core/database/migrations/2017_04_28_223840_create_subscribers_table.php

Column	Type	Index
id	int, auto-increment	PRIMARY KEY
workspace_id	unsigned int	Single index
hash	string (UUID)	UNIQUE
email	string	Single index
first_name	string, nullable	?
last_name	string, nullable	?
meta	json, nullable	?
unsubscribed_at	timestamp, nullable	Single index
unsubscribe_event_id	unsigned int, nullable	FK
created_at	timestamp	Single index
updated_at	timestamp	?

Related pivot table sendportal_tag_subscriber already has:

• idx_tag_subscriber on (tag_id, subscriber_id)
• idx_subscriber_tag on (subscriber_id, tag_id)

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2. Issues Found

P0 ? Critical

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2.1 Missing workspace_id filter in bulk sync (security + correctness)

File: sendportal-core/src/Http/Controllers/Api/SubscribersController.php:107

// CURRENT ? no workspace_id scope
DB::table('sendportal_subscribers')->whereIn('email', $emails)->get();

The initial email lookup in the sync() endpoint has no workspace_id filter.
This can pull subscribers from other workspaces, leaking data across tenants.
The follow-up query at line 160 does add the scope, making the pair inconsistent.

Fix:

DB::table('sendportal_subscribers')
    ->where('workspace_id', $workspaceId)
    ->whereIn('email', $emails)
    ->get();

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2.2 Unbounded ->get() on full export

File: sendportal-core/src/Http/Controllers/Subscribers/SubscribersController.php:157

// CURRENT ? loads entire table for this workspace into memory
$this->subscriberRepo->all(Sendportal::currentWorkspaceId(), 'id');

Called on every CSV export request. A workspace with tens of thousands of subscribers
will either time out or exhaust PHP memory.

Fix: Use a database cursor to stream rows one at a time:

$this->subscriberRepo->cursor(Sendportal::currentWorkspaceId());

Or chunk the output with chunkById() and stream the response incrementally.

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2.3 Full-wildcard LIKE search ? guaranteed full table scan

File: sendportal-core/src/Repositories/Subscribers/BaseSubscriberTenantRepository.php:115-118

// CURRENT ? leading % makes all three conditions non-sargable
->where('first_name', 'LIKE', '%' . $name . '%')
->orWhere('last_name',  'LIKE', '%' . $name . '%')
->orWhere('email',      'LIKE', '%' . $name . '%')

A leading % wildcard prevents the query planner from using any index.
Every search request forces a full scan of the subscribers table.

Fix options (choose one based on requirements):

Option	Trade-off
Change to prefix search 'text%'	Uses the email index; loses mid-string matching
Add MySQL FULLTEXT index on (first_name, last_name, email) and use MATCH ? AGAINST	Stays in MySQL; requires MyISAM or InnoDB FULLTEXT
Integrate Laravel Scout (Meilisearch / Typesense)	Best UX; adds infrastructure dependency

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P1 ? High

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2.4 N+1 queries in CSV import loop

File: sendportal-core/src/Services/Subscribers/ImportSubscriberService.php:28-43

For every row in the import file, the loop issues:

1. findBy(id) ? one query
2. findBy(email) if the ID lookup missed ? second query
3. Lazy-loads the tags relationship on the result

A 1,000-row CSV triggers up to 3,000 queries.

Fix: Batch-fetch all emails before the loop, then resolve from memory:

$emails  = collect($rows)->pluck('email')->filter()->all();
$existing = Subscriber::where('workspace_id', $workspaceId)
    ->whereIn('email', $emails)
    ->with('tags')
    ->get()
    ->keyBy('email');

foreach ($rows as $row) {
    $subscriber = $existing->get($row['email']);
    // upsert logic here ? no further queries needed
}

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2.5 Missing composite indexes

MySQL cannot combine two separate single-column indexes for a multi-column WHERE clause.
All of the queries below currently cause MySQL to pick one index and filter the rest in memory.

Method	File:Line	WHERE / ORDER BY columns
countActive()	BaseSubscriberTenantRepository.php:81	workspace_id AND unsubscribed_at IS NULL
getRecentSubscribers()	BaseSubscriberTenantRepository.php:88	workspace_id ORDER BY created_at DESC
getGrowthChartData()	MySqlSubscriberTenantRepository.php:16	workspace_id AND unsubscribed_at AND created_at
storeOrUpdate()	ApiSubscriberService.php:30	workspace_id AND email

Recommended migration:

-- Covers storeOrUpdate lookup and enforces email uniqueness per workspace at DB level
ALTER TABLE sendportal_subscribers
    ADD UNIQUE INDEX idx_workspace_email (workspace_id, email);

-- Covers countActive and status-filtered list queries
ALTER TABLE sendportal_subscribers
    ADD INDEX idx_workspace_unsubscribed (workspace_id, unsubscribed_at);

-- Covers getRecentSubscribers and date-sorted list queries
ALTER TABLE sendportal_subscribers
    ADD INDEX idx_workspace_created (workspace_id, created_at);

-- Covers getGrowthChartData (multi-condition chart query)
ALTER TABLE sendportal_subscribers
    ADD INDEX idx_workspace_unsub_created (workspace_id, unsubscribed_at, created_at);

Note: idx_workspace_email (UNIQUE) also eliminates a race condition ? email uniqueness
per workspace is currently validated only at the application layer, allowing duplicates
under concurrent inserts.

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2.6 Duplicate tag query in edit() action

File: sendportal-core/src/Http/Controllers/Subscribers/SubscribersController.php:102

The edit action loads the subscriber (with relationships), then issues a second query
to pluck tag IDs ? even though the tags collection is already on the loaded model.

Fix: Replace the second query with the already-loaded relationship:

// Before (two queries)
$subscriber = $this->subscriberRepo->find(...);
$tags = Tag::pluck(...); // separate query

// After (one query)
$subscriber = $this->subscriberRepo->find($workspaceId, $id, ['tags']);
$selectedTagIds = $subscriber->tags->pluck('id');

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P2 ? Medium

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2.7 GROUP BY on a timestamp function bypasses index

Files:

• sendportal-core/src/Repositories/Subscribers/MySqlSubscriberTenantRepository.php:26,34
• sendportal-core/src/Repositories/Subscribers/PostgresSubscriberTenantRepository.php (same pattern)

// CURRENT ? function wrapper prevents index usage
->groupByRaw("date_format(created_at, '%d-%m-%Y')")
->groupByRaw("date_format(unsubscribed_at, '%d-%m-%Y')")

Wrapping a column in a function prevents the query planner from using the index on that column.

Fix (MySQL): Use DATE(created_at) and add a generated column index if the dashboard
query runs frequently:

ALTER TABLE sendportal_subscribers
    ADD COLUMN created_date DATE GENERATED ALWAYS AS (DATE(created_at)) STORED,
    ADD INDEX idx_workspace_created_date (workspace_id, created_date);

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2.8 No pagination on tag/subscriber relationship endpoints

Files:

• sendportal-core/src/Http/Controllers/Api/TagSubscribersController.php:40
• sendportal-core/src/Http/Controllers/Api/SubscriberTagsController.php:40

Both endpoints eager-load the entire relationship with no limit.
A tag with 100,000 subscribers returns all rows in a single response.

Fix: Add paginate() to both endpoints and document the per_page parameter in the API.

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3. Improvement Plan (Prioritised)

#	Priority	Issue	File	Action
1	P0	Missing workspace_id in sync	Api/SubscribersController.php:107	Add .where('workspace_id', $workspaceId)
2	P0	Unbounded export ->get()	Subscribers/SubscribersController.php:157	Replace with cursor/chunked streaming
3	P0	Full-wildcard LIKE search	BaseSubscriberTenantRepository.php:115	Prefix search or FULLTEXT index
4	P1	N+1 in import loop	ImportSubscriberService.php:28	Batch fetch before loop
5	P1	Missing composite indexes	DB schema	New migration with 4 composite indexes
6	P1	Duplicate tag query in edit()	Subscribers/SubscribersController.php:102	Use already-loaded relationship
7	P2	GROUP BY on timestamp function	MySqlSubscriberTenantRepository.php:26,34	Use DATE() + generated column index
8	P2	No pagination on relationship endpoints	Api/TagSubscribersController.php:40	Add paginate()