diff --git a/src/assessment/entities/assessment.entity.ts b/src/assessment/entities/assessment.entity.ts
index fb51befa..fb8e9128 100644
--- a/src/assessment/entities/assessment.entity.ts
+++ b/src/assessment/entities/assessment.entity.ts
@@ -1,6 +1,9 @@
 import {
   Column,
   CreateDateColumn,
+  OneToMany,
+  PrimaryGeneratedColumn,
+  Index,
   DeleteDateColumn,
   Entity,
   OneToMany,
@@ -14,12 +17,14 @@ export class Assessment {
   id: string;
 
   @Column()
+  @Index()
   title: string;
 
   @Column({ nullable: true })
   description?: string;
 
   @Column()
+  @Index()
   durationMinutes: number;
 
   @OneToMany(() => Question, (q) => q.assessment, {
diff --git a/src/assessment/entities/question.entity.ts b/src/assessment/entities/question.entity.ts
index 4f57fc14..aff1d244 100644
--- a/src/assessment/entities/question.entity.ts
+++ b/src/assessment/entities/question.entity.ts
@@ -1,3 +1,4 @@
+import { ManyToOne, PrimaryGeneratedColumn, Index } from 'typeorm';
 import { Column, DeleteDateColumn, Entity, ManyToOne, PrimaryGeneratedColumn } from 'typeorm';
 import { QuestionType } from '../enums/question-type.enum';
 import { Assessment } from './assessment.entity';
@@ -8,9 +9,11 @@ export class Question {
   id: string;
 
   @Column({ type: 'enum', enum: QuestionType })
+  @Index()
   type: QuestionType;
 
   @Column()
+  @Index()
   prompt: string;
 
   @Column({ type: 'json', nullable: true })
diff --git a/src/common/utils/websocket.utils.ts b/src/common/utils/websocket.utils.ts
index 5c268115..58d99bc6 100644
--- a/src/common/utils/websocket.utils.ts
+++ b/src/common/utils/websocket.utils.ts
@@ -47,7 +47,9 @@ class WebSocketManager {
     }
 
     const userConnections = this.connections.get(userId) ?? new Set();
-  
+
+    const userConnections = this.connections.get(userId);
+
     if (!userConnections) {
       return;
     }
diff --git a/src/courses/entities/course.entity.ts b/src/courses/entities/course.entity.ts
index 43eb7400..d00ac7a6 100644
--- a/src/courses/entities/course.entity.ts
+++ b/src/courses/entities/course.entity.ts
@@ -19,6 +19,7 @@ export class Course {
   id: string;
 
   @Column()
+  @Index()
   title: string;
 
   @Column('text')
diff --git a/src/email-marketing/entities/campaign.entity.ts b/src/email-marketing/entities/campaign.entity.ts
index 79adbd31..87772367 100644
--- a/src/email-marketing/entities/campaign.entity.ts
+++ b/src/email-marketing/entities/campaign.entity.ts
@@ -9,6 +9,7 @@ import {
   OneToMany,
   OneToOne,
   JoinColumn,
+  Index,
 } from 'typeorm';
 import { ApiProperty } from '@nestjs/swagger';
 
@@ -25,10 +26,12 @@ export class Campaign {
 
   @ApiProperty()
   @Column()
+  @Index()
   name: string;
 
   @ApiProperty()
   @Column()
+  @Index()
   subject: string;
 
   @ApiProperty({ required: false })
@@ -41,6 +44,7 @@ export class Campaign {
 
   @ApiProperty({ required: false })
   @Column({ nullable: true })
+  @Index()
   templateId?: string;
 
   @ManyToOne(() => EmailTemplate, { nullable: true })
@@ -53,14 +57,17 @@ export class Campaign {
 
   @ApiProperty({ enum: CampaignStatus })
   @Column({ type: 'enum', enum: CampaignStatus, default: CampaignStatus.DRAFT })
+  @Index()
   status: CampaignStatus;
 
   @ApiProperty({ required: false })
   @Column({ nullable: true })
+  @Index()
   scheduledAt?: Date;
 
   @ApiProperty({ required: false })
   @Column({ nullable: true })
+  @Index()
   sentAt?: Date;
 
   @ApiProperty()
diff --git a/src/gamification/entities/user-progress.entity.ts b/src/gamification/entities/user-progress.entity.ts
index 5c5dc834..fbe04ccd 100644
--- a/src/gamification/entities/user-progress.entity.ts
+++ b/src/gamification/entities/user-progress.entity.ts
@@ -1,4 +1,4 @@
-import { Entity, PrimaryGeneratedColumn, Column, OneToOne, JoinColumn } from 'typeorm';
+import { Entity, PrimaryGeneratedColumn, Column, OneToOne, JoinColumn, Index } from 'typeorm';
 import { User } from '../../users/entities/user.entity';
 
 @Entity('user_progress')
@@ -8,14 +8,18 @@ export class UserProgress {
 
   @OneToOne(() => User)
   @JoinColumn()
+  @Index()
   user: User;
 
   @Column({ default: 0 })
+  @Index()
   totalPoints: number;
 
   @Column({ default: 1 })
+  @Index()
   level: number;
 
   @Column({ default: 0 })
+  @Index()
   xp: number;
 }
diff --git a/src/payments/entities/invoice.entity.ts b/src/payments/entities/invoice.entity.ts
index 3d8e6781..ca1c671c 100644
--- a/src/payments/entities/invoice.entity.ts
+++ b/src/payments/entities/invoice.entity.ts
@@ -6,6 +6,7 @@ import {
   UpdateDateColumn,
   ManyToOne,
   JoinColumn,
+  Index,
 } from 'typeorm';
 import { Payment } from './payment.entity';
 import { User } from '../../users/entities/user.entity';
@@ -31,15 +32,18 @@ export class Invoice {
   id: string;
 
   @Column({ type: 'varchar', unique: true })
+  @Index()
   invoiceNumber: string;
 
   @Column({ type: 'decimal', precision: 10, scale: 2 })
+  @Index()
   amount: number;
 
   @Column({ type: 'decimal', precision: 10, scale: 2, default: 0 })
   taxAmount: number;
 
   @Column({ type: 'decimal', precision: 10, scale: 2 })
+  @Index()
   totalAmount: number;
 
   @Column({ type: 'varchar', length: 3, default: 'USD' })
@@ -53,12 +57,15 @@ export class Invoice {
     enum: InvoiceStatus,
     default: InvoiceStatus.DRAFT,
   })
+  @Index()
   status: InvoiceStatus;
 
   @Column({ type: 'date', nullable: true })
+  @Index()
   issuedDate: Date;
 
   @Column({ type: 'date', nullable: true })
+  @Index()
   dueDate: Date;
 
   @Column({ type: 'text', nullable: true })
@@ -72,6 +79,7 @@ export class Invoice {
   payment: Payment;
 
   @Column({ name: 'payment_id' })
+  @Index()
   paymentId: string;
 
   @ManyToOne(() => User, (user) => user.id)
@@ -79,6 +87,7 @@ export class Invoice {
   user: User;
 
   @Column({ name: 'user_id' })
+  @Index()
   userId: string;
 
   @CreateDateColumn()