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

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2
votes
1answer
164 views

Foreign Key Constraint over two tables

I am trying to put the following entity-model into practice: We have a list of Payments, each Payment belongs to a certain store and is of a certain payment type (e.g. 10€ maintenance cost in Store1,...
0
votes
2answers
238 views

What is the best way to find out the sum of a field from a table?

I am making a accounting software. I have a table debit_credit that contains double entry accounting records Here is my example data.Table is: debit_credit_id | tran_id | ledger_head_id | debit | ...
1
vote
1answer
157 views

Count childs of parent with sql or save in column?

In postgres I have a threaded setup where parent id has many childs and childs can have childs. What is the most efficient way to get the count with a sql statement similar to this: WITH RECURSIVE ...
1
vote
1answer
49 views

Real-world scenarios for table with DENY SELECT and GRANT [INSERT/UPDATE/DELETE] [closed]

What is real-world scenarios for this type of permissions? May be it is generally not valid, and made by mistake? Should this kind of permissions be avoided (or prohibited)?
2
votes
0answers
42 views

How To Manage Random Data Without Repitition?

We have a database design problem of a Learning System. Please can somebody help us ? These are the requirements : A person can register for a module which has "n" number of questions. The person ...
2
votes
0answers
186 views

How to store data where various subcategories have specific columns?

I'm new to database designing. I'll use MySQL and PHP. I'm designing a database in which I have a lot of categories and subcategories like given below: Product Table p_id p_title category_id ...
2
votes
1answer
74 views

Migrate existing SQL Server database file to smaller files

I have a database that is about 1TB in size. It's currently on a 2TB hard drive and I would like to replace it with a few 512GB SSD. I need to split the existing database file (.mdf) into multiple ...
3
votes
0answers
34 views

View of structurally same tables [closed]

Let's say I have two schemas (HR and Finance for example), in each schema I have a table with information about document types this department works with. Tables have the same structure: HR.doc_type ...
2
votes
2answers
97 views

Three-sided many-to-many relationship design

I have 3 entity that have a relation to each other. My entities are: OPTION PLAN PRICE Relationships: PLAN and OPTION have a many-to-many relationship Map of PLAN and OPTION has a many-to-many ...
1
vote
0answers
26 views

How do you output field changes in mysql the most efficiently?

I have a rather large employee feed coming in and each employee has about 50 fields. I take the employee data and add on a bunch of other stuff and this gets outputted to one of our vendors. Most ...
1
vote
1answer
173 views

Is my shopping list database schema good enough?

I'm wondering if my schema is correct? It's intended to hold shopping list items for each user, a user belongs to a household. Items will be added to the household. The stocklist will to hold the ...
1
vote
2answers
64 views

Database design - need someone to guide me

Im probably doing this wrong, but here it goes. Im trying to build something like very basic CRM. I know there are plenty of them, but I want something to learn actually. Requirements: Some ...
4
votes
2answers
57 views

Best db setup to accomplish yes/no list of clients for daily calls

I will preface this by saying I am a relative novice to Access but I have managed to develop some basic databases. I have some working knowledge of expressions and macros but VBA is still a bit of a ...
4
votes
1answer
489 views

Can jsonb do fast search by *value* or even a partial value? Other types?

I have a person table where arbitrary data must be inserted. Since I'm using Postgres 9.4, jsonb appears to be the right choice. Example data: id: 1, name: "Joe Doe", preferences: { color: "red" , ...
5
votes
3answers
237 views

Why would I need a third table in a one-to-many relationship?

Good day, Our db professor at the univeristy always said that one-to-many relationships with (0, M) in one side MUST have a third table to relate them. I did not ask him back then and now I cannot, ...
0
votes
2answers
45 views

Multiple types of parts with multiple types of information (unspecified amount) [duplicate]

I'm having trouble designing a database for a project I was working on recently. It's to do with a garage management system. So I've realised I need to store multiple types of parts (Tyres, engines, ...
3
votes
4answers
3k views

Finding all date ranges that overlap a target date range

Say I wish to store when staff are on holiday (FromDate, ToDate) and then I wish to find all staff that are on holiday between two given dates (QFromDate, QToDate). Now assume that I have many such ...
8
votes
3answers
235 views

Is it reasonable to mark all columns but one as primary key?

I have a table representing movies. The fields are: id (PK), title, genre, runtime, released_in, tags, origin, downloads. My database cannot be polluted by duplicated rows, so I want to enforce ...
0
votes
0answers
33 views

database polymorphic associations: design for foreign key point to itself

I have a database design that used to solve polymorphic assocations problem. Here is my schema: Post(PostID, PostType) Question(QuestionID, QuestionTitle, QuestionContent) // QuestionID references ...
6
votes
1answer
163 views

PostgreSQL and table inheritance

I'm not sure if this is the right place for this, so please feel free to tell me if it is off-topic or there is a better place to post. I am working on a fantasy sports based project, and the number ...
0
votes
1answer
59 views

Should we store sum of values in a column, or store in memory database

I have a bunch of questions and answers and total votes of those questions and answers. My requirement that I always show how many votes for a question or a answer (and user doesn't often click to who ...
1
vote
1answer
102 views

Tables design for conversation

I want to create simple conversation module on my site. So I need a list of users who had conversation with current user. I need to show amount of new messages in each conversation. I think about next ...
2
votes
2answers
87 views

Database design appoach confirmation

I am working for a mortgage company in migrating a legacy application to new application for managing claims, means lender fore close a loan and request for a claim to get its funds from government or ...
0
votes
1answer
50 views

Using Year Ranges vs Row for Each Year

I'm working on a database in SQL Server for a project. My background is in data analysis and although I'm familiar with database design I don't have a lot of experience. The project revolves around ...
0
votes
0answers
34 views

Help for design DB, avoiding circular relationships

Help for design DB, I have user, order, scratch_card and transaction tables. When user place an order, one record will add to order and another one to transaction as withdraw and when user recharge ...
1
vote
1answer
93 views

SELinux is preventing pg_ctl from read access on the file postgresql.conf

I am trying to setup a master-slave PostgreSQL 9.4 database on Fedora 22, with the slave database's PGDATA being different from the default /var/lib/pgsql/data/ directory. I wrote this to /etc/systemd/...
2
votes
1answer
51 views

Distinguishing Records with Related Fields

I'm a newer user (obviously) and would greatly appreciate question writing suggestions as well as answer suggestions: I have a lot of interrelated tables which largely depend on my Products table, ...
1
vote
0answers
71 views

Automatically set table name prefix according to other field in PowerDesigner

I'm working with PowerDesigner 16.5 and I have a PDM generated out of its corresponding LDM. The table names are inherited from the LDM and I'm fine with them, but I would like to generate the DDL ...
1
vote
1answer
60 views

Sharding VS Replication

To improve query response will it be better to shard the data or replicate existing shards for faster response. In case of sharding the data might be nicely distributed and hence the queries. In ...
1
vote
1answer
164 views

Database schema for entities with two possible owner/parent types?

I'm using PostgreSQL with Sequelize as my ORM. I have one type, User. The second type is Group, which can have any number of users associated with it through a GroupMemberships table. Users can also ...
0
votes
0answers
41 views

SSAS bridge table with Slowly changing dimensions

I am designing a datamart using the basic principles of Kimball for use in SSAS. I have a many many to many attribute relationships (multi-valued dimension objects), however I have a few questions: ...
1
vote
1answer
53 views

Category entity relationship / subtype relationships design

I am looking to implement a generic comment and file attachment facility within a web application which would be used across various parts and allow users to provide comments and add attachments to ...
0
votes
0answers
54 views

Versioning database tables

I need to store all the changes made for almost every table in a meta-data database. I am thinking about storing every previous version in a JSON array or XML in the table. Like: CREATE TABLE [dbo].[...
3
votes
1answer
144 views

Stored procedure deployment - push or pull into database? [closed]

Using stored procedures as part of an ETL process to populate tables in another database, which method would be considered a best practice (if any) in terms of deployment, maintenance, visibility and ...
1
vote
1answer
81 views

Items and their tags

This is my table design: CREATE TABLE IF NOT EXISTS `items` ( `id` int(11) NOT NULL AUTO_INCREMENT, `title` varchar(255) NOT NULL, `description` mediumtext NOT NULL, `...
0
votes
2answers
2k views

How to export Oracle database without data

I want export my Oracle database with its structure such as tables, schema, users, tablespaces, datafiles and everything but without the contained data.
0
votes
0answers
57 views

Chicken and egg problem with JOIN tables and memberships

So I'm having a problem where users are able to access certain models that depend on a join model that doesn't exist at the time of the access. Quick overview of the use case: Basic school ...
1
vote
3answers
2k views

SSIS: How to check if a record DOESN'T exist in flat file but exists on the database

I am working on preparing an SSIS job where I am importing a .CVSV file to OLE DB destination (sql database). We are going to get these files on daily basis. The .CSV file contains records of doctors. ...
2
votes
1answer
198 views

What is a suitable,stable, high performing database for Large Financial Time Series Data? [closed]

I realise this question may have be answered in some form but I would like to gather the thoughts and opinions of actual users with experience in this field of Database design and development. I have ...
1
vote
0answers
177 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. ...
3
votes
1answer
59 views

Schema for scarce goods

I have following objects: (Rooms) which are (available in a certain period of time [in days]). During the time of availability they can be (booked) by (users). There are basically these four tables. I ...
5
votes
3answers
613 views

MySql Invoice and Subscription Schema

I have an ecommerce db built and I'm adding subscriptions. See the simplified structure below. orders id, customer_id order_items id, order_id, product_id invoices id, order_id subscriptions id, ...
0
votes
0answers
91 views

Looking for feedback on a design for a simple task manager

I've got tired of using notepad / excel to manage my tasks at work. Since tasks may sometimes contain sensitive data, my boss will not allow us to use an online task management system, so I've decided ...
5
votes
1answer
278 views

How to model “Courses prerequisites” for a university?

I am trying to model a courses structure and dependencies of a university. For example, in the Computer Engineering department you need to do Data Structures before doing Artificial Intelligence. But ...
1
vote
1answer
175 views

DB design for employee working hours constraints [closed]

I have a simple employee schedule database (I use PostgreSQL): employees: - id - name - email shifts: - start - stop - employee_id Now there is need to apply constraint for working hours. ...
1
vote
3answers
132 views

Include logical key on each table vs. join

I'm designing a database that is used to track an inventory item through its lifecycle. I'm currently relating my tables using the previous lifecycle event's ID (for example, a shipment contains the ...
0
votes
1answer
49 views

How to get last messge between two friends in the messge table having id in descending order?

Hi friends help me to solve this problem ," display all last messages of a user from all his/her friends" My sample message table is --------------------------------------------------- | id | msg ...
2
votes
1answer
861 views

Personal finance database design

I'm making a personal finance management application in PHP and MySQL, for learning myself some more PHP and MySQL. This system is currently using 4 tables: users, this table holds all the user ...
8
votes
3answers
152 views

Why NOT partition?

When would one NOT want to partition a database? (thinking MySQL partitioning) In my case I'll be starting with a couple millions rows, it should grow from there. Primary key on a character field ...
3
votes
1answer
337 views

Storing created/retired dates for a large amount of different entities

In the db I'm working on now almost every entity has these 4 columns: CreatedDate CreatedBy RetiredDate RetiredBy Usually this is used for logging purposes, and for some of the entities the ...