feat(segment): add indexes for common query paths

Add indexes to frequently queried and foreign-key columns on the
segment entity and create a migration to apply them to existing
databases.

Avoid duplicate or redundant indexes while covering common WHERE,
ORDER BY, JOIN, and foreign-key lookups.

Author: fathiaoyinloye

src/email-marketing/entities/segment.entity.ts

@@ -7,6 +7,7 @@ import {
   DeleteDateColumn,
   OneToMany,
   VersionColumn,
+  Index,
 } from 'typeorm';
 import { ApiProperty } from '@nestjs/swagger';
 import { SegmentRule } from './segment-rule.entity';
@@ -24,6 +25,7 @@ export class Segment {
   version: number;
 
   @ApiProperty()
+  @Index('IDX_segments_name')
   @Column()
   name: string;
 
@@ -32,6 +34,7 @@ export class Segment {
   description?: string;
 
   @ApiProperty()
+  @Index('IDX_segments_isDynamic_createdAt', ['isDynamic', 'createdAt'])
   @Column({ default: true })
   isDynamic: boolean;
 
@@ -53,6 +56,9 @@ export class Segment {
   @UpdateDateColumn()
   updatedAt: Date;
 
+  @Index('IDX_segments_deletedAt', ['deletedAt'], {
+    where: '"deletedAt" IS NULL',
+  })
   @DeleteDateColumn()
   deletedAt?: Date;
 }

src/migrations/1806000000000-add-segment-indexes.ts

@@ -0,0 +1,33 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+/**
+ * Adds indexes to the `segments` table for the common list and lookup paths:
+ *
+ *  - `name` lookup / search
+ *  - `isDynamic` + `createdAt` for active/dynamic segment listings ordered by newest first
+ *  - `deletedAt IS NULL` for soft-delete filtering while retaining an efficient active-only index
+ *
+ * These cover the primary query paths without introducing redundant single-column indexes
+ * on the already-prefixed composite `isDynamic, createdAt` index.
+ */
+export class AddSegmentIndexes1806000000000 implements MigrationInterface {
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      'CREATE INDEX IF NOT EXISTS "IDX_segments_name" ON "segments" ("name")',
+    );
+
+    await queryRunner.query(
+      'CREATE INDEX IF NOT EXISTS "IDX_segments_isDynamic_createdAt" ON "segments" ("isDynamic", "createdAt")',
+    );
+
+    await queryRunner.query(
+      'CREATE INDEX IF NOT EXISTS "IDX_segments_deletedAt" ON "segments" ("deletedAt") WHERE "deletedAt" IS NULL',
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query('DROP INDEX IF EXISTS "IDX_segments_deletedAt"');
+    await queryRunner.query('DROP INDEX IF EXISTS "IDX_segments_isDynamic_createdAt"');
+    await queryRunner.query('DROP INDEX IF EXISTS "IDX_segments_name"');
+  }
+}