The logical model and/or physical design of a database.

learn more… | top users | synonyms (4)

1
vote
0answers
169 views

Ticket booking engine

I am going to build a flight ticket booking system. My client has own planes. Under is basic concept of engine. Admin will add flights. Passengers, agents, franchises or admin will book the tickets. ...
1
vote
0answers
38 views

Design optimization

I'm designing a database for a crm like software. Actually it's my first project so i'm learning on the run on this one. I have customer and employee tables. I also have a history table for tracking ...
1
vote
0answers
62 views

Get all data from two tables and group it into different category in mysql

These are my tables to build an FAQ: CREATE TABLE `tbl_section` ( `section_id` int(11) NOT NULL AUTO_INCREMENT, `section_title` varchar(100) NOT NULL, PRIMARY KEY (`section_id`), ...
1
vote
0answers
26 views

Uninitialized values: ignore or set?

From the implementation point of view for a database, is it preferable to handle optional form fields by setting to some default value (e.g. false, 0, "", etc.) or just ignore such fields (do nothing ...
1
vote
0answers
72 views

What is the best design for dynamic assignment of locations for variable sized grid boxes to occupy?

I want to build a database that will have limited single locations to put boxes. It's divided by lanes and bays. Imagine a 4x4 grid, totally 16 slots, every time I query the table, I want to return ...
1
vote
0answers
90 views

Database design/layout

I have an objective to record and store test data. A secondary objective is to track the progress of the test programme (it is a large programme). So I want to use MySQL (not Access or DOORS) to ...
1
vote
0answers
34 views

Managing logs generated by user

I am developing a web app for my client and there is a section which displays the changes made in the application by any of the user. This section is known as log.It basically stores and displays the ...
1
vote
0answers
174 views

best way to log large amounts of data

I'm building a new logging system for our company. I'm wondering about the best way to store about 50-100GB data each year. I'm looking at both MySQL and MongoDB. I'm considering MongoDB because it ...
1
vote
0answers
22 views

Calculate Num_Index_Pages for sizing design

I don't understand Step2 #8 Calculate the number of number of non-leaf pages in the index. I am not sure I understand the "Level". I have Num_Leaf_Pages=508 & Index_Rows_Per_Page=476 I don't ...
1
vote
0answers
705 views

Facing Failed to read stream error - mysql_native_password error

I have been facing the following error intermittently on MySQL. Authentication to host '127.0.0.1' for user 'root' using method 'mysql_native_password' failed with message: Reading from the ...
1
vote
0answers
68 views

Couchbase data modeling

I come from the Relational DB world (SQL), and I'm getting started with NoSQL. So please consider that when answering. I have two Buckets: Apps and Users. A user may be subscribed to N ...
1
vote
0answers
127 views

Storing table history - is this a good use case for Postgres's table partitioning / inheritance?

I currently have a products table which stores product information (title, description, tags, manufacturer, etc.) for a website. I would like to store historical information of changes to this table ...
1
vote
0answers
230 views

Most effective way to manage a growing list of time series data in an MS Access database

I am building a database to store time series data along with some other summary statistics. Since this is a local application I do not have access to more robust database solutions and am confined to ...
1
vote
0answers
34 views

Which method would be more secure and feasible in the long term?

The concern here is a confusion between two alternative methods for storing data. Our product migrates records from any service A to any service B. These services define their own records and the ...
1
vote
0answers
70 views

Best practices to segment people and attributes for advertising database

we have a database where we store people some attributes per person in the following tables: people (id, name, email, phone) people_attributes (id, person_id, attribute_name, attribute_value) ...
1
vote
0answers
23 views

Dummy Objects vs. NULLs: optionality for three-way relationship

In a nutshell, I'm trying to model a relationship and can't decide whether to allow NULLs or to require values and use dummy objects (in place of NULL). Here are the details. I have three classes: ...
1
vote
0answers
105 views

how to resolve this insurance company database

Company offers 3 types of personal motor insurance to vehicle owners. It includes the third party insurance, fire and theft, and comprehensive cover. All vehicle owners need to purchase a motor ...
1
vote
0answers
76 views

Table with both primary key and unique key

My system requirement defines a unique business/domain/natural key (i.e. <yyyymmdd><branch_id><running_number>, in bigint). Should I use this unique key as primary key or I should ...
1
vote
0answers
83 views

What is the difference between 2 phase locking and strict 2 phase locking?

2 phase locking is used to ensure isolation of database transactions (by ensuring serializability). But there is another term called Strict 2 phase locking. I find it hard to understand the ...
1
vote
0answers
47 views

What are my options in creating this Location table?

Say I have an Items table. Each item has a location associated to it. This location can either be a city, a state or a country. I believe this could normally be solved with a column Type in the ...
1
vote
0answers
101 views

Good way to store daily train data in MongoDB

I am preparing to collect large amounts of information about trains in my country. Each train in my country has a number. I've already collected all of these numbers. There are about 4000 of them. ...
1
vote
0answers
44 views

Implementing a consistent mailbox

I am trying to implement something like a mailbox for short messages between users. I am using Postgresql 9.4.1 with SQLAlchemy (Python3). There is a table of users: users = Table('users',metadata, ...
1
vote
0answers
56 views

Help with ER design

So i am trying to create a db for a restaurant as a homework assignment.. However there is a spot that confuses me and involves the dish entity. "Every dish must belong to a category ...
1
vote
0answers
86 views

Database schema design for individual configurations

I'm trying to design a database schema that allows me to store customer custom built products. As a simplified example: A user can buy a cupboard, draws, boxes, and dividers. A cupboard has 2 tiers. ...
1
vote
0answers
40 views

How to query against legacy data that needs to be cleaned up?

I have an existing SQL Server DB with 3 tables (note: this is a made up example, but modelled after a real problem). Artists : contains music artists MusicRecords : contains information on music ...
1
vote
0answers
133 views

How to store likes to posts in Parse.com database?

In my parse database I have a classed called Post and Like. Should I create a field likes in Post class with Relation<Like> type or there is another better option of storing likes in Parse DB?
1
vote
0answers
81 views

Nosql multiple database design to handle sharing scenarios

This question is regarding design of a database in mongodb. The scenario: A user has a drive which he can share with others. Drive has two categories: docs and others. The user has three choices in ...
1
vote
0answers
623 views

What are the different types of binary relationship types?

I'm new to databases and while studying questions on it, I've come across one that I can't find the answer to. Define the three different binary relationship types that are common in relational ...
1
vote
0answers
130 views

Normalized database table with non-atomic values

I'm creating a normalized table for a questionnaire that the customers fill in and in one of the columns is a field called "extra comments". I realize that with the "extra comments" field, the data ...
1
vote
0answers
36 views

Enforce referential integrity for FriendRequest table that has UserA and UserB

I have a table called User that has UserName as a primary key. I want to establish a relationship with enforced referential integrity between User and FriendRequest. FriendRequest has the following: ...
1
vote
0answers
54 views

testing an extraneous attribute in a relation using functional dependency

I am studying the book "Database System Concepts" by sudarshan . In chapter 8.4.3 in a dependency alpha->beta , If A ∈ aplha to check if A is extraneous, let (gamma = alpha − { A}), and check if ...
1
vote
0answers
136 views

DB Design: Looking for Performance improvement with a Column used in all SQL Queries

I recently got added to a new ASP .NET Project(A web application) .There were recent performance issues with the application, and I am in a team with their current task to Optimize some slow running ...
1
vote
0answers
86 views

Relational or non-relational database for a system to pass objects on?

hopefully this is the right place to ask this kind of question. I am working on a system that focuses on helping people give away things that they don't use anymore. So, an object typically has the ...
1
vote
0answers
438 views

How to handle many columns / variable schema?

I apologize in advance in case this question has been asked already. I'm working on revamping a reporting application used within my company. The requirements are: Support addition of new fields ...
1
vote
0answers
283 views

Conceptual model vs Logical model vs Physical model

I'm doing a work about database, and now I need to show three different images, one image with the conceptual model, other with logical model and other with physical model of a database. I'm looking ...
1
vote
0answers
204 views

Dealing with Multiple User Roles

I'm working on a project based on a CMS, where there is a built-in roles table. However, the CMS allows a user to have one role only using role_id And these are the requirements that struggling me: ...
1
vote
0answers
28 views

Optimize finding the next batch of data from A to be crunched and inserted into B

I'm using PostgreSQL to store data produced by a large distributed computation. There are several stages to this computation; the idiom we've settled on is that there's a table containing the results ...
1
vote
0answers
183 views

“Replicate” Table structures with sp_addscriptexec

In our customers environment is a massive central server (running SQL Server Enterprise 2008R2) and some distributed PCs (running SQL Server Standard 2008R2). The central server has a replication for ...
1
vote
0answers
688 views

Postgresql - How to Convert all Column Names to Lowercase

I have a travel survey with a series of tables (lots and lots of columns) that I exported from MS Access into a postgres database. I've search around a lot for an explanation of how to convert all the ...
1
vote
0answers
23 views

Modeling for inclusion of two different entities

What I Have I am currently hashing out the data model for an application that will utilize MongoDB. In my setup, users or members (as they are called in the schema) will be created and then assigned ...
1
vote
0answers
864 views

How to generate data for News Feed efficiently like facebook , googleplus , twitter e.t.c?

I have created table as post ( post_id int(15) auto_increment primary key , user_id int(11) , post_text varchar(2000) , post_type int(1), ...
1
vote
0answers
26 views

Difference in the workload related to data-amount and search option

A couple of days ago I was asked why it is necessary to use the first normal form also for separation of names. We have a table which stores private customers (Name+Surname;Information) and business ...
1
vote
0answers
43 views

Basic Design Question about one to many in a table

Sorry for the basic question but I am new to all of this! Say I have a table named Runs, and each table has Run: id (primary_key) data (String - path to a data file) status timestamp ... ...
1
vote
0answers
41 views

Second opinion about elimination of possible redundant database column

We currently have a Widgets database table were we track the widgets the company produces. When a widget is produced the widget information is added to this table. This Widgets table contains a Status ...
1
vote
0answers
34 views

A better model for connecting users to different objects, even efter they cease to exist

I've got the privilege to create a small in-house application for managing todo-lists, although I am not really a developer. (I know some PHP and SQL, and got a chance to prove myself). As my ...
1
vote
0answers
140 views

Can somebody check this normalisation workings i think i am missing a step or a dependency somewhere

given these two tables: and: I need to first list them as an un-normalised structure(s) then i need to identify the functional dependencies/primary keys. Once i have done this i must represent ...
1
vote
0answers
238 views

How to join the tables in mysql to get wall messages and comments with name of person ? Only user and his friends messages

I have four tables in my mysql database as shown in the image url provided. I want to select data from the tables without duplication. I want to show messages and comments on wall according to the ...
1
vote
0answers
36 views

Keys of a relation

I got relation: R = { (ABCDEF) , (A B F -> C, B C -> F, F -> A, F -> B, D E -> E, E -> D)} keys of this relation are: {BCE}, {EF} But i dont get it... why? Why not only {EF}.. it got less ...
1
vote
0answers
1k views

SQLite Design: Better to have many tables with few columns or few tables with many columns?

I am struggling to figure out the best design for a Sqlite database that will hold data about Facebook pages so that I can calculate benchmarks for how the average Facebook page performs. I have an ...
1
vote
0answers
148 views

Best practices for ranking records in flexible way

Suppose we have 10000 records of any product. User search on our website with his given criteria. so we output search results based on given criteria. Now Admin want to rank products in search. so ...