CSCI235-Assignment 3 Implementation of Database Transactions.

This assignment includes the tasks related to implementation of database transactions. 

 

Prologue 
If VirtualBox is not installed yet then install it on your system first. It is explained at

 

https://documents.uow.edu.au/~jrg/115/cookbook/e1-1frame.html 

 

how to install and how to use VirtualBox.

 

Use one of the links given below to download Ubuntu18.04-64bits-MongoDB4.2.2-08-JAN-2020.ova file with an image of virtual machine running MongoDB 4.2.2 on Ubuntu 18.04. You can also use the links published in a section OTHER RESOURCES on Moodle.

 

OneDrive:

https://uowmailedu-

my.sharepoint.com/:u:/g/personal/jrg_uow_edu_au/EYCB0u8xnOR

CkApv9kaYgMsBC3MyOkAdH8Kyl_J8OrVfJw?e=wVlLbB 

 

GoogleDrive:

https://drive.google.com/open?id=1kzGEb521LS3HCYatgoVKU1hMhlDG89h 

 

CloudStor: (When downloading from CloudStor you must use Firefox browser)

https://cloudstor.aarnet.edu.au/plus/s/qg8J3vE4SoxRzKo 

 

 

Start VirtualBox and import a virtual machine Ubuntu18.04-64bits-MongoDB4.2.2-08-JAN-2020.ova.  

 

Next, start the virtual machine and login as an Ubuntu Linux user CSCI235 with a password csci235.

 

Next, start Terminal program and within a Terminal window start MongoDB server in the following way.  

 

mongod –dbpath DATA –port 4000 

 

A server displays a lot of messages.  A successful start of MongoDB server is confirmed with a message like

 

… 

… I NETWORK  [initandlisten] waiting for connections on port 4000… 

… 

 

pretty well hidden somewhere at the end of a long list of other messages issued by the starting server.  

 

Note, that the Terminal window you use just now becomes a console of the running MongoDB server and you cannot use it any more. Do not close the Terminal window ! Just minimize it.

 

Open a new Terminal window. To create a BSON collection orders use a command

 

cd CSCI235 

 

to move to CSCI235 folder with the scripts.  

 

Next, to start a command line client mongo process the following command.

 

mongo –port 4000 

 

To create a collection orders and to load the documents into the collection, process the scripts employees.js, suppliers.js, and customers.js at prompt in the following way.

 

load("employees.js"); load("suppliers.js"); load("customers.js"); 

 

Next, you can use the methods  

 

db.orders.find().count() and   

db.orders.find().pretty()  

 

to count the total number of the documents in a collection bookshop and to list all documents in a pretty format.

 

Next try few simple queries.

 

For example, to list information about a hierarchy of customers submitting orders that consist of products process a method

 

db.orders.find({"CUSTOMER":{$exists:true}}).pretty(); 

 

For example, to list information about a customer who has a contact name Maria 

Anders and the orders submitted by the customer process a method

 

db.orders.find({"CUSTOMER.contact name":"Maria Anders"}).pretty(); 

 

For example, to list information about an order that has order id 325 process a method

 

db.orders.find({"CUSTOMER.submits.ORDER.order id":325}).pretty(); 

 

The conceptual and logical schemas of a collection orders are available in the files dbschema-bson.bmp and bsonschema.bmp in section SAMPLE DATABASES on Moodle. It is strongly recommended to make yourself familiar with the conceptual and logical schemas of a sample database.

 

No report is expected from implementation of the actions included in Prologue section.

                                                                                                                                                  

 


Tasks 
Task 1 Data manipulations
 

Download and unzip a file solution1.zip. You should get a file solution1.js. The file contains the specifications of the following 10 data manipulation operations on a collection orders.  

 

(1)        Append a new product Changde Noodles that belongs to a category Noodles to a list of products supplies by a supplier located in a city Zaandam. All other information is unknown at the moment. Display the names of products supplied by a supplier located in a city Zaandam.

 

(2)        Remove information about a product Longlife Tofu supplied by a supplier Tokyo Traders. Display the names of products supplied by a supplier Tokyo Traders.

 

(3)        Increase a unit price of a product Flotemysost by 100%. Display the product name and the changed unit price in a pretty format.                     

 

(4)        Rename a key submits to a key sends in the orders submitted by a customer FAMIA. Display all information about a customer FAMIA.              

 

(5)        An order with order_id equal to 310 is now handled by an employee with employee id equal to 7. Update the database. After update display order_id and employee id in a pretty format.                                                                                                     

 

Implement the data manipulations listed above in a data manipulation language of MongoDB. Write your solutions into the empty slots following a specification of each data manipulation in a file solution1.js. Do not remove the specifications of the data manipulations and semicolons following the specifications.

 

Implementation of each data manipulation is worth 1 mark. 

 

When ready create a report from processing of the data manipulations in the following way.  

 

Use gedit editor to open a file solution1.js with the specifications and implementations of the data manipulations.  

 

Select the entire contents of the file and Copy it into a buffer.  

 

Open a new Terminal window and start mongo client in the following way.

 

mongo –port 4000 

 

Paste the contents of the buffer copied earlier from gedit window in front of prompt of mongo client. You may have to press Enter key to process the last data manipulation in a case when it is not followed by a newline control character.

 

Select the entire contents of the Terminal window and Copy&Paste it into a file solution1.lst. Save a file solution1.lst.

 

Deliverables
A file solution1.lst with a report from processing of MongoDB script solution1.js with the implementation of the data manipulations listed above.  

 

And again, please remember that:

-      a report without the specifications of the data manipulations and listings of the processed data manipulations scores no marks,

-      a report that contains any kind of processing errors scores no marks.

                                                                                                                                                              


Task 2 Query processing and data transformation with aggregation framework
 

Download and unzip a file solution2.zip. You should get a file solution2.js. The file contains the comments with the specifications of the following 5 queries and data transformations.  

 

(1)     Save all information about the names of products supplied by a supplier Gai paturage into a collection products1. Display in a pretty format without document identifiers all documents in a collection products1.

 

(2)     Save all information about the names of products supplied by a supplier Gai paturage into a collection products2 that consists of the documents like {"product name": a-name-of-product}. Display in a pretty format without document identifiers all documents in a collection products2.

 

(3)     Find the total number of products in a collection orders. Display a result in a format

{"total number of products":integer-value}.

 

(4)     List in the ascending order the ids of the first 3 employees who handled at least one

order. Display the results in a format {"employee id":a-value-of employee-id}. List only distinct values.

 

(5)     Find the company names of suppliers together with the total number of supplied products by each company. Display the results in a format {"total products":integer-value,"company name":a-company-name}.

 

Use the methods aggregate() and pretty() to implement the queries and data transformations and to display the results. Note, that you may need two or more statements to implement a single task.

 

Implementation of each query/data transformation is worth 1.5 mark.

 

When ready create MongoDB script file solution2.js with the implementations of your queries and create a report from processing of the data manipulations in the following way.  

 

Use gedit editor to open a file solution2.js with the specifications and implementations of the data manipulations.  

 

Select the entire contents of the file and Copy it into a buffer.  

 

Open a new Terminal window and start mongo client in the following way.

 

mongo –port 4000 

 

Paste the contents of the buffer copied earlier from gedit window in front of prompt of mongo client. You may have to press Enter key to process the last data manipulation in a case when it is not followed by a newline control character.

 

Select the entire contents of the Terminal window and Copy&Paste it into a file solution2.lst. Save a file solution2.lst.

 

Deliverables
A file solution2.lst with a report from processing of MongoDB script solution2.js with the implementation of the data manipulations listed above.  

 

Please remember that:

-      a report without the specifications of the queries and data manipulations and listings of the processed queries and data manipulations scores no marks,

-      a report that contains any kind of processing errors scores no marks.

                                                                                                                                                              

 


Task 3
Implementation of indexing 

 

Download and unzip a file solution3.zip. You should get a file solution3.js.

 

Consider the documents included in a collection orders and the queries consistent with the following query templates.

 

(1)     Find the company name, contact name, and contact title of the customers with a given company name.

(2)     Find the company name of the customers who submitted an order with a give date.

(3)     Find the names of products ordered by the customers living in a given city.

(4)     Find the names of countries the customers live in.

 

Repeat the implementations of the following four steps for each one of the query patterns listed above.

 

Step 1 Create an index that speeds up processing of a query consistent with a pattern.

 

Step 2 Apply a method getIndexes() to list all existing indexes, for example db.collection.getIndexes().

 

Step 3 Apply a method explain() to verify whether the system plans to use the indexes created for processing of a query consistent with a pattern, for example db.collection.find({"country":"Sweden", "greetings":"Tjenare"}).explain(). 

The constants used in a query are up to you.

 

Step 4 Drop an index created in Step 1 with a method dropIndex(), e.g. db.collection.dropIndex("index_name").  

You can find a name given to an index by the system from the results of Step 2.

 

Write your solutions into a file solution3.js in the empty slots following a specification of each problem. Do not remove the comments with the specifications of queries and semicolons following the comments !

 

Implementation of each index, displaying query processing plans and dropping an index  is worth 1 mark.

 

When ready create a report from processing of the queries in the following way. Use gedit editor to open a file solution3.js with the specifications of the queries and implementations of the queries.

 

Select the entire contents of the file and Copy it into a buffer.

Open a new Terminal window and start mongo client in the following way.

 

mongo –port 4000 

 

Paste the contents of the buffer copied earlier from gedit window in front of prompt of mongo client. You may have to press Enter key to process the last query in a case when it is not followed by a newline control character.

 

Select the entire contents of the Terminal window and Copy&Paste it into a file solution3.lst. Save a file solution3.lst. Examine the contents of a file solution3.lst for possible errors.

 

Deliverables
A file solution3.lst with a report from processing of MongoDB script solution3.js with the implementation of indexing, listing the indexes and query processing plans, and dropping the indexes.

 

And again, please remember that:

-  a report without the listings of applied methods and feedback messages issued by MongoDB scores no marks,

-  a report that contains any kind of processing errors scores no marks.

                                                                                                                                                              


Task 4
Implementation of validation with JSON schema 

 

Download and unzip a file solution4.zip. You should get a file solution4.js.

 

Start a command line interface mongo to MongoDB database server and process the following statements.

 

db.adminCommand( {setFeatureCompatibilityVersion:"4.2"} ) use test; 

 

The first statement sets an appropriate compatibility level for application of JSON schema validator and the second statement sets an appropriate default database to be used with JSON Schema validator.

 

No report is expected from the actions listed above.

 

Consider the following conceptual schema of a database that contains information about suppliers and products.

 

  

 

An objective of this task is to create a new collection of documents task4 that contains information represented by a conceptual schema above and such that the collection is validated with JSON schema validator.

 

Use a method createCollection() to create a collection of documents task4 and use JSON schema validator to enforce the following constraints on the collection.

 

(1)     Information about products must be nested within information about suppliers.

(2)     Information about keywords describing products must be nested within information about products.

(3)     The values associated with the key names company name, city, (within SUPPLIER class), product name, keywords (within PRODUCT class) must be of type string. All values are mandatory.

(4)     The values associated with a key postal code (within SUPPLIER class must be of type integer in a range 0..9999.

(5)     The values associated with a key units in stock (within PRODUCT class) must be of type integer and must be positive.

(6)     The values associated with a key unit price must be of type double and must be positive and less than 100.00.

(7)     A key company name is mandatory.

 

Next, insert into a collection task4 two sample documents. The first document must pass all validations of the constraints listed above. The second document must fail a validation of only one of the constraints listed above. Provide information why a document fails a validation.

 

Write your solutions into a file solution4.js in the empty slots following a specification of each problem. Do not remove the comments with the specifications of queries and semicolons following the comments !

 

When ready create a report from processing of the queries in the following way.

 

Use gedit editor to open a file solution4.js with the specifications of the queries and implementations of the queries.

 

Select the entire contents of the file and Copy it into a buffer.

 

Open a new Terminal window and start mongo client in the following way.

 

mongo –port 4000 

 

Paste the contents of the buffer copied earlier from gedit window in front of prompt of mongo client. You may have to press Enter key to process the last query in a case when it is not followed by a newline control character.

 

Select the entire contents of the Terminal window and Copy&Paste it into a file solution4.lst. Save a file solution4.lst. Examine the contents of a file solution4.lst and make sure that it does not contain any errors.

 

Deliverables
A file solution4.lst with a report from processing of MongoDB script solution4.js with an implementation and testing of the validations.

 

And again, please remember that:

-  a report without the listings of applied methods and feedback messages issued by MongoDB scores no marks,

-  a report that contains any kind of processing errors except failed validation of the second document scores no marks.