diff --git a/examples/db-problems-demo/.gitignore b/examples/db-problems-demo/.gitignore
new file mode 100644
index 00000000..549e00a2
--- /dev/null
+++ b/examples/db-problems-demo/.gitignore
@@ -0,0 +1,33 @@
+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
diff --git a/examples/db-problems-demo/pom.xml b/examples/db-problems-demo/pom.xml
new file mode 100644
index 00000000..eec2be97
--- /dev/null
+++ b/examples/db-problems-demo/pom.xml
@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.3.4.RELEASE</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>ru.otus</groupId>
+	<artifactId>db-problems-demo</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>db-problems-demo</name>
+	<description>Demo project for Db usage problems </description>
+
+	<properties>
+		<java.version>11</java.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-jdbc</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-thymeleaf</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.flywaydb</groupId>
+			<artifactId>flyway-core</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+			<version>1.4.200</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.postgresql</groupId>
+			<artifactId>postgresql</artifactId>
+			<version>42.2.17</version>
+		</dependency>
+
+
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.vintage</groupId>
+					<artifactId>junit-vintage-engine</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>
diff --git a/examples/db-problems-demo/readme.md b/examples/db-problems-demo/readme.md
new file mode 100644
index 00000000..d70fff70
--- /dev/null
+++ b/examples/db-problems-demo/readme.md
@@ -0,0 +1 @@
+Проект с миграцией для демонстрации того, как выглядит джойн нескольких таблиц при связи "многие-ко-многим"
\ No newline at end of file
diff --git a/examples/db-problems-demo/src/main/java/db/migration/R__0002_Add_books.java b/examples/db-problems-demo/src/main/java/db/migration/R__0002_Add_books.java
new file mode 100644
index 00000000..84e9608b
--- /dev/null
+++ b/examples/db-problems-demo/src/main/java/db/migration/R__0002_Add_books.java
@@ -0,0 +1,60 @@
+package db.migration;
+
+import org.flywaydb.core.api.migration.BaseJavaMigration;
+import org.flywaydb.core.api.migration.Context;
+import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
+import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
+import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
+import org.springframework.jdbc.datasource.SingleConnectionDataSource;
+
+import javax.sql.DataSource;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+@SuppressWarnings("unchecked")
+public class R__0002_Add_books extends BaseJavaMigration {
+
+    public static final int BOOKS_COUNT = 100_000;
+
+    @Override
+    public void migrate(Context context) throws Exception {
+        DataSource ds = new SingleConnectionDataSource(context.getConnection(), true);
+        NamedParameterJdbcOperations jdbc = new NamedParameterJdbcTemplate(ds);
+
+        insertBooks(jdbc);
+        insertBooksRelations(jdbc);
+    }
+
+    private void insertBooks(NamedParameterJdbcOperations jdbc) {
+        List<Map<String, Object>> params = new ArrayList<>(BOOKS_COUNT);
+        for (int i = 0; i < BOOKS_COUNT; i++) {
+            String bookTitle = String.format("Заголовок книги #%d", i);
+            String bookTextPart = String.format("Это текст книги #%d", i);
+            String bookText = bookTextPart.repeat( 8000 / bookTextPart.length());
+            params.add(new MapSqlParameterSource("title", bookTitle)
+                    .addValue("bookText", bookText)
+                    .getValues()
+            );
+        }
+        jdbc.batchUpdate("insert into books (title, book_text) values (:title, :bookText)",
+                params.toArray(new Map[0]));
+    }
+
+    private void insertBooksRelations(NamedParameterJdbcOperations jdbc) {
+        List<Map<String, Object>> paramsForAuthors = new ArrayList<>(BOOKS_COUNT);
+        List<Map<String, Object>> paramsForGenres = new ArrayList<>(BOOKS_COUNT);
+        for (int i = 1; i <= BOOKS_COUNT; i++) {
+            for (int j = 1; j <= 3; j++) {
+                paramsForAuthors.add(new MapSqlParameterSource("bookId", i).addValue("authorId", j).getValues());
+                paramsForGenres.add(new MapSqlParameterSource("bookId", i).addValue("genreId", j).getValues());
+            }
+        }
+        jdbc.batchUpdate("insert into books_authors (book_id, author_id) values (:bookId, :authorId)",
+                paramsForAuthors.toArray(new Map[0]));
+
+        jdbc.batchUpdate("insert into books_genres (book_id, genre_id) values (:bookId, :genreId)",
+                paramsForGenres.toArray(new Map[0]));
+    }
+
+}
diff --git a/examples/db-problems-demo/src/main/java/ru/otus/dbproblemsdemo/DbProblemsDemoApplication.java b/examples/db-problems-demo/src/main/java/ru/otus/dbproblemsdemo/DbProblemsDemoApplication.java
new file mode 100644
index 00000000..ed8a5ff4
--- /dev/null
+++ b/examples/db-problems-demo/src/main/java/ru/otus/dbproblemsdemo/DbProblemsDemoApplication.java
@@ -0,0 +1,24 @@
+package ru.otus.dbproblemsdemo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+import java.sql.SQLException;
+
+/*
+SELECT * FROM AUTHORS;
+SELECT * FROM GENRES;
+SELECT * FROM BOOKS_AUTHORS ;
+SELECT * FROM BOOKS_GENRES;
+SELECT * FROM BOOKS;
+SELECT * FROM BOOKS_ALL_INFO ;
+ */
+
+@SpringBootApplication
+public class DbProblemsDemoApplication {
+
+	public static void main(String[] args) throws SQLException {
+		SpringApplication.run(DbProblemsDemoApplication.class, args);
+	}
+
+}
diff --git a/examples/db-problems-demo/src/main/resources/application.yml b/examples/db-problems-demo/src/main/resources/application.yml
new file mode 100644
index 00000000..ea3a99d4
--- /dev/null
+++ b/examples/db-problems-demo/src/main/resources/application.yml
@@ -0,0 +1,13 @@
+spring:
+  datasource:
+    #url: jdbc:h2:mem:testdb
+    url: jdbc:postgresql://localhost:5432/problems
+    username: postgres
+    password: postgres
+    driver-class-name: org.postgresql.Driver
+    initialization-mode: never
+  h2:
+    console:
+      enabled: true
+  flyway:
+    enabled: true
\ No newline at end of file
diff --git a/examples/db-problems-demo/src/main/resources/db/migration/1.0/V1_1__2020_10_10_Initial_schema.sql b/examples/db-problems-demo/src/main/resources/db/migration/1.0/V1_1__2020_10_10_Initial_schema.sql
new file mode 100644
index 00000000..dda2b660
--- /dev/null
+++ b/examples/db-problems-demo/src/main/resources/db/migration/1.0/V1_1__2020_10_10_Initial_schema.sql
@@ -0,0 +1,23 @@
+--date: 2002-10-10
+--author: stvort
+
+create table authors (id bigserial, name varchar(50), primary key (id));
+create table genres (id bigserial, name varchar(50), primary key (id));
+create table books (id bigserial, title varchar(50), book_text varchar(8000), primary key (id));
+create table books_authors (book_id bigint not null references books (id) on delete cascade , author_id bigint not null references authors (id) on delete cascade);
+create table books_genres (book_id bigint not null references books (id) on delete cascade , genre_id bigint not null references genres (id) on delete cascade);
+
+
+create view books_all_info as
+select b.id as "ID книги",
+       b.title as "Заголовок книги",
+       b.book_text as "Текст книги",
+       a.id as "ID автора",
+       a.name as "Имя автора",
+       g.id as "ID жанра",
+       g.name as "Название жанра"
+from books b left join
+     books_authors ba on b.id = ba.book_id left join
+     books_genres bg on b.id = bg.book_id left join
+     authors a on ba.author_id = a.id left join
+     genres g on bg.genre_id = g.id;
diff --git a/examples/db-problems-demo/src/main/resources/db/migration/data/R__0001_Add_catalogsl_data.sql b/examples/db-problems-demo/src/main/resources/db/migration/data/R__0001_Add_catalogsl_data.sql
new file mode 100644
index 00000000..ff10f291
--- /dev/null
+++ b/examples/db-problems-demo/src/main/resources/db/migration/data/R__0001_Add_catalogsl_data.sql
@@ -0,0 +1,15 @@
+insert into authors(id, name)
+values (1, 'Админ Супервайзерович Рут'),
+       (2, 'Валентина Игоревна Априори'),
+       (3, 'Питуний Дельфинович Автостопов'),
+       (4, 'Инокентий Купертинович Жужа');
+
+insert into genres(id, name)
+values (1, 'Детектив'),
+       (2, 'Фантастика'),
+       (3, 'Фэнтези'),
+       (4, 'Техническая литература');
+
+
+
+