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

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122 views

Best away to keep monthly records of loans

I'm trying to make a database to keep records of the amounts payed on a loan on a monthly basis. I already have tables for the clients, accounts, products and loans: create table product( id ...
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196 views

Are these One-to-Zero-or-One relationship correct?

I'm working with SQL Server 2012 and I have these three tables: CREATE TABLE [dbo].[CODES] ( [CODE] [nvarchar](20) NOT NULL, [ ... ] , CONSTRAINT [PK_CODES] PRIMARY KEY CLUSTERED ( ...
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692 views

Is an ER diagram an example of a conceptual, logical or physical schema?

I have been reading databases, and I clearly understand the difference between a conceptual, logical and physical schema. An ER diagram is an example of which of these schema's?
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1answer
53 views

Warehouse Database Design Question

Apologies if this has been answered previously but I have been unable to get a specific model to work. I have a database table that needs to store some very basic info for a reporting system. The ...
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2answers
94 views

Inheritance of unknown type at creation time

Say I have a table called People into which people are inserted from the moment they are born. Now lets say I want some subclasses of people based on their job. So there are also tables for Plumber, ...
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3answers
2k views

Is a 5+ column primary key bad for large (100 million+) table?

I was reading about some real life DB issues, and one project had a 100 million row plus table that had 5 columns as its primary. I'm thinking this is bad, but can anyone tell me exactly why? EDIT: ...
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40 views

Auto number for big data

I'm working with application that can have millions of data. Just wondering if it is ok to use auto_number as primary key. I have read that bigint, int etc has limit. So for example site is on live ...
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1answer
52 views

What does a CONSTRAINT have to do with my unique index?

I have to indexes on my table. The first was created by Django and the second by me. I'm not completely certain what the extra CONSTRAINT means in the first index and am wondering how I would change ...
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26 views

Database separation of backend users and member users

I'm creating a website that has 2 kind of users. Backend users and member/frontend users. There are some same functionality on both users. I'm thinking if it is ok to separate them, instead of ...
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1answer
844 views

Allow access to enter data through forms, but not full database access

Using Access 2013 or Sharepoint 2013 is it possible to give someone access to data entry forms that work with a back end database whether Access database or Sharepoint SQL. But from everything I've ...
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10 views

How many postgresql / BDR database can be replicated from a server? [duplicate]

I've been reading the postgresql bdr docs found here: https://wiki.postgresql.org/wiki/BDR_User_Guide I came across this comment in the above doc: BDR operates per-database, not per-cluster ...
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27 views

These relationships are redundant?

I have the following entities for a clinic. Patient visit the clinic for diseases (study) and physician(s) will exam the patient and create a report for each desease. physician visit study report ...
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1answer
45 views

Is it possible to execute queries in random order?

I have a list of INSERTs, UPDATEs and DELETEs queries. My problem is that I always receive them in the wrong order (random), and I cannot know their original order. Are there techniques to ...
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2answers
139 views

Sporadic execution time causing timeouts [closed]

We have a table with 100 million records holding 24 hour worth of data of our clients' customers actions (actions which are performed on 3rd party sites and replicated from there to our server) The ...
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1answer
415 views

“Entity Attribute code uniqueness” error in PowerDesigner

I am using PowerDesigner to do Conceptual Data modeling. If I use the same attribute name in more than one entities, I will get above error when I run "check model" or try to generate Logical Data ...
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27 views

Procedure Security Layer

I want discuss an idea with you and get your opinions what you think about it. From database (SQL Server 2008 R2) administration view and general security, its good practice to create DB roles and set ...
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0answers
71 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 ...
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3answers
808 views

Table Design for Student Attendance hourly for each day

I have created a table (attendance_details) for storing every day attendance of Students in MySQL. Need to capture attendance for hourly (1-8hrs) every day. I have the student details in separate ...
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1answer
52 views

How to design a database for storing phone attribute?

I'm trying to capture following attributes : Name,Company,Price,Size,Weight,Release date,Gms,No of sim,Camera details,SIM details,Screen size,Screen type,Processor and Ram details and all.. Any lead ...
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22 views

Is the use of my lookup table efficient?

I'm trying to find the best way to architect the relationship in the scenario that: A team can have multiple players, a player may also have multiple teams My first thought was to use a lookup ...
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29 views

Data base design for handling website subscriptions

I have a website where at least 20 posts are posted in a day and each post contains more than 5 categories and each category has further tags. I wanted to build a subscription module that users can ...
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0answers
121 views

Table Design For Patterned Data Using Variable Bucket Ranges

Looking for table design for this scenario to be implemented on SQL Server 2012 instance. Scenario There are a total of seven types of reported data, each with variable number buckets of ...
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0answers
54 views

ERD to data structure

I'm new to databases. I converted my ERD to data structure. Althougt I made sure all the 1NF, 2NF and 3NF are handled, I'm skeptic about it. This is the data structure. Port(PortID(pk), Name, ...
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1answer
1k views

Pros and cons of using many schemas in PostgreSQL as opposed to just one?

For a large SAAS application (backed by PostgreSql 9.4), with over 300,000 accounts (and growing), what are the pros and cons of using a schema per account to partition the data vs putting all the ...
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2answers
106 views

Question about choosing primary key

My scenario is that I have a super type named PERSON and two sub types EMPLOYEE and CUSTOMER. I use the Primary key from PERSON, PersonID, in both EMPLOYEE and CUSTOMER as foreign keys. However, I ...
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0answers
79 views

MySQL 5.1.73-cll and engine MyISAM PRO AND CONS FOR THE FOLLOWING 2 'DELETE' APPROACHES [closed]

For MySQL 5.1.73-cll and engine MyISAM what are the pros and cons for the following two possibilities of 'deleting' rows(let's say that a user want's to delete his profile/delete some of his products ...
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1answer
81 views

Database Design Question? Relationships and Form Data

I am working on a project that requires to store evaluation form data. Essentially, the a reviewer will fill out a form based on the performance of the person being evaluated. Now there is well over ...
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2answers
175 views

Query parent table and get child tables columns

I have two tables, one inherits the other: CREATE TABLE parent ( col1 INTEGER ); CREATE TABLE child ( col2 INTEGER ) INHERITS( parent ); // Insert some data INSERT INTO parent( col1 ) ...
3
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2answers
201 views

Is EAV an appropriate design for a collection of coexisting metadata-rich “fact estimates” on objects? [closed]

I'm attempting to architect a system that will collect estimates on various quantities (10+) on each of many (300K+) objects, and make decisions from the historical record of these estimates. For ...
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1answer
61 views

Does my database design work? Newbie!

I've uploaded an image of my database design below. This is the first database I have designed and I was hoping that I could get some input into whether or not it is set up correctly or if I just have ...
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1answer
49 views

Database design for a group-buying site

What is the best way to approach the database design for a group-buying site? If you are not familiar with group buying, people purchase a deal, and when "n" amount of people purchase the deal, the ...
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0answers
72 views

A transition table, is it a good idea?

I'm writing an application that stores a project's C++ API representation. For example, I have tables like Class, Function, FunctionParameter, DerivedClass, BaseClass, and so on. Every once in a ...
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1answer
112 views

BLObs – Should I Store In Database Or in Directory Structure?

BLObs – Should I Store In Database Or in Directory Structure I have been developing a database to replace an ageing data structure that contains 1000's of files within a directory structure. The ...
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3answers
219 views

Prepopulate database with empty / null values [mysql]

What would be the best way to pre-populate a database with 100 empty fields and then begin the Auto_Increment? What I mean to say, I want to reserve the first 100 userfields (ie UIDs which are ...
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55 views

What is the name for a table that keeps track of operations that have been performed on the database?

It's name is Trans_Log It has the following fields: TL_User (database user logged in) TL_WinUser (name of windows user logged in) TL_Date (date of operation?) TL_Type (type of operation / function ...
2
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1answer
47 views

Using the same table for entities that are almost alike when it breaks foreign key integrity?

I'm designing a website with a database that should support events that a user can sign up for, fx. a concert. Users can sign up using our internal registration system, or using an external website ...
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1answer
54 views

Primary keys: composite and singular

In general when I design tables I always include a single unique field, even if it there is already a unique combination of columns available to create a primary key. This field is usually either a ...
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57 views

How to create and select entities in MongoDB?

I'm a newbie in MongoDB and I'm trying to understand how to create objects there and how to select them in comparison with relational databases. So I need an example how to perform these things. ...
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1answer
78 views

How to save the design of an Access database — not the content — as text?

How can I save the entire design or specifications of an Access 2007 database -- not the data content -- as text? I have fallen foul of the "Enter Parameter Value" bug whereby a query pop-up shows an ...
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39 views

How to reference a table mapping that is not initially known in another table

I have four tables: ExternalName, InternalName, ExternalInternalNameMap, and Transaction. ExternalName and InternalName have a many to many relationship. ExternalInternalNameMap is the junction table ...
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70 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 ...
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1answer
1k views

Select rows from table where each row refers to a different schema

I have customer table in public schema. And I have a schema named after each customer. Each customer schema contains different tables like portals, plugin, ... When I want to select portals used by ...
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1answer
689 views

Use a set database schema or EAV design? [duplicate]

I have already created a database design with a set schema. The database schema is for a web quotation form. PS it is not a simple quotation form and hence need to customise the form, form builders ...
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0answers
44 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 ...
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1answer
59 views

Which one is best solution for future database structure?

I'm working on a big web application. so i need to create user_preference_table it has the marks for every users for each attributes. here attributes are games so in the user_preference_table i need ...
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2answers
63 views

SQL Server 2012: set a column to only use a single case?

Is there a way to tell SQL Server 2012 to store both A and a as A (or both A and a as a) for some given column such that every insert statement does not need to have UPPER() in it?
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1answer
27 views

Help me define the tables in this scenario

We have 2 tables setup like this: WEB_GK_STATE PRG_CODE Varchar2(5) STATE Varchar2(2) WEB GK PRG_CODE Varchar2(5) TEXT Varchar2(4000) Here is some sample data: ...
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2answers
163 views

Normalising Customers and Employers with a people table

At what normalisation stage is it recommend to split say Customers and Employees into a people table and then link to the unique attributes of Customers and Employees. I cant seem to find the ...
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1answer
207 views

Uber-wide tables: Time to switch to Mongo?

As a web developer, I've typically only worked with nice, normalized tables in SQL-based RDBMS, but I'm doing some data consolidation for a researcher who will be analyzing correlations between all ...
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30 views

Advice for a friendship table

For my little project I would like to create a very simple friendship system. And I would like someone to give me some advice/criticise the current design I have. Here is an example of my friend ...