Database design is the process of specifying the logical and/or physical parts of a database. The goal of database design is to make a representation of some "universe of discourse" - the types of facts, business rules and other requirements that the database is intended to model.

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105 views

Unable to decompose this relation to BCNF

I have a relation R = { A, B, C, D, E, F, G, H, I } And functional dependencies F ={ ABC -> DE E -> C AB -> F C -> G F -> H H -> IJ F -> B } I am able to do simple BCNF ...
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124 views

key value database

I have one object and a lot of data associated with that object, you can think of it as something like facebook timeline where we have user and user has a lot of posts. I cannot store data in JSON ...
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271 views

Improving database design for category based site

I'm working on a site that gets about 30k visits a day and it makes use of a lot of queries which uses UNION's over about 45 different tables, these tables generally range from about 15k rows to about ...
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23 views

User is An employee. Role or relation

I've created a database based on a party-model. In short I show you the tables: parties, kind, party_to_party_relations, role, party_roles table parties: CREATE TABLE `parties` ( `id` int(11) NOT ...
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19 views

Best practice to create a database schema for Open Auth (Social logins)

I've done a database schema for user management alongs with their roles and permissions. The problem actually began, when I decide to integrate a multiple "Open Auths" such as Facebook Login, Google ...
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40 views

mysql - suggestions for table design with huge number of columns

We have a table that consists of a huge number of columns (usually between 500 to 1000, depends on our clients websites). We are suffering from speed issues due to this, and we're looking for the best ...
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31 views

How to make a query from a database with schemas to a database without schemas, and vice versa, with DBLINK in postgres

I have a DB (DB1) in postgres 9.4 who use DBLINK to query another DB (DB2), and vice versa, using views and functions. But now i have to add 2 schemes to DB1 (CLIENT1 And CLIENT2) and i want when i ...
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19 views

FastReport / Report Query Help - How do i convert a integer value into a string?

I am using FastReport to create my reports and I have an issue. I am trying to make a form with the data in ProductMaster.ITEMBUYINGPRICE. The output of this column is a 6-digit value showing the ...
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38 views

Does MySQL InnoDB compression combined with Windows compression save more space?

We have a very large MySQL InnoDB database, compressed using the following syntax at the end of the table declaration: ENGINE=InnoDB ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=4 We also have windows ...
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8 views

Where to put a 0..1 fk column when already having 0..n fk’s on one side and 0..1 on the other

I have a transaction table that represents user’s credit transactions and two tables containing different entities, but both interacting with the transaction table. Say, payment_with_state and ...
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25 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 ...
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27 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 ...
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20 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: ...
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42 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 ...
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34 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 ...
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30 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 ...
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38 views

What happens to the database structure when i add a nonclustered index

Our team is working for a while now with Azure SQL. After a lot of trying , we managed to add a sync group between the main DB and the backup one. Of course, this means that for every change in the ...
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37 views

MySQL Db design: Optional data in separate table or as NULL values in original table

I am having following problem: User fills out the form, which consists of two sets of fields - header (basic information about biological observation) and detail (measurements and advanced ...
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33 views

Where to put the currency field?

Abbreviated I have following tables: Companies own flats and rent them for specific periods_in_time and lastly a currencies table. The price column is sitting in the periods_in_time table. But where ...
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24 views

Multiple table relationship for different scenarios!

We have the following heirarchy in our platform; Package is comprised of Products, Products is comprised of Services and Services are comprised of SKUs. The relationship between them is many-to-many ...
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15 views

Fill the 5th table with 3 other tables data in LibreOffice

I have 5 tables primary key foreign key felh(felh_id, felh_nev) gepek(gepid, felh_id, gep_nev) lic(lic_id, lic_k, lic_l, lic_db, gep_id) pr(pr_id, pr_n, pr_vr, lic_id) haszn(haszn_id, gep_id, pr_id, ...
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17 views

Data Warehouse for reporting - 6 Dimension tables,or 1 table and 6 views?

Problem: I have been asked to add a Dimension table to our data warehouse and create the ETL tasks to populate it. Lets call the table "DimInternalFault". The source table for DimInternalFault is ...
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89 views

MySQL log tables design

I have to make 25 modification historic tables from 26 tables. I need a design for each table that could grow more than 75,000,000 of rows. I use InnoDB for 25 tables and 1 with MyISAM. I have one ...
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33 views

Database structure for sport venue booking

I'm building a system that allows booking of slots to play games at any sport venue. Now, different sporting venues have different schedules. So I've thought of a plan that allows multiple venues to ...
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86 views

Design database schema for membership application with fees and purchases

My membership application needs to record payment of membership fee, card fee and misc. fee for each member. I also need to record purchases of each members and payments for the purchases.
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32 views

How can I correct my untrusted foreign key situation?

In our scenario, we have a number of situations in which foreign keys or check constraints are not trusted. Here's some example situations: A "claim" is an entity that is the primary purpose of the ...
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15 views

Does an Object literal always mean the Predicate and Object form a key-value property on the Subject?

A triple is Subject-Predicate-Object, e.g. Post Office - Not Open - Sunday. Consider another example, Post Office - Size in Square Feet - "4000" For this example, I have two observations: the ...
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70 views

DB schema for an invoice system with tiered prices

I've been hired by a payment gateway company that handles payments for its customers. Every month, a script is run and will charge each merchant for the bulk number of payments completed. The unit ...
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66 views

Referral table structure

I need to make a simple referral system and I have a database table set out as follows: mem_id | date | refer_email | accepted And the meaning of such columns is the following: mem_id: The ...
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13 views

Determining the 3NF based on functional dependencies

Given a relation R = {E M L T} and functional dependancies LT -> E, ET -> L, TM -> E, and E -> M , I know that the superkeys of this relation is TL, TE, and TM. For 3NF, the left hand dependancies ...
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19 views

What factors would cause me to favor inheritence over composition in a small database?

I have identified two choices for how to model addresses in my corporate entity database. Method 1: inheritance Table 1: Addresses [data table, primary key = (id)] id (integer) - primary key ...
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41 views

Loop through fields on a before-insert trigger?

Here's my table: CREATE TABLE foo ( i_am_pk CHARACTER VARYING(255) PRIMARY KEY NOT NULL, dont_touch_this CHARACTER VARYING(255) NOT NULL, name CHARACTER VARYING(255) NOT NULL, addr CHARACTER ...
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43 views

DB Design for Mobile App Clients

Hello I am new to designing DB for Mobile App where speed is the Key. My Mobile App will request to WebAPI and WebAPI will get data from MySQL. I have designed my tables in MySQL as per relational ...
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33 views

table design approach for a rental application with several one to many relationships

I'm trying to go about designing a database/tables for the following situation I'm being presented. I'm developing a rental web application with MySQL as db engine. It is for a nonprofit organizations ...
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12 views

When to use tags vs binary fields in a constituent management system?

I have a table of Constituents and I want to track yes or no qualities like: are they a teacher? are they an elected official? are they philanthropists? There will be less than a dozen of these ...
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120 views

Ideas for Database schema for Automotive web app

For the last couple of days I have been searching all over Google for database schema for my automotive web application [like a marketplace of sort] (in Laravel 5 PHP). I have tried many models some ...
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101 views

MySql Innodb Database Slow INSERT Query to Remote Server

I have searched thoroughly on how to improve general performance of my database which is hosted on Hostgator. I have mostly come across performance tuning strategies which are catered to only local or ...
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41 views

Post categories model for a user submission wedbsite

I'm building an user submission site where users can make posts to content_types: Blog, Movies, Photos, Forums. Since these content types only have slight variances I would like to keep them in one ...
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25 views

IBM Data stage compiler error

I have installed InfoSphere Datastage 9.1.2 on Windows Server 2008 R2, and also installed C++, but when I try to compile a job show error in transform stage.
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35 views

Mysql - too many Deletion - Insertion

I'm creating crons for my OLAP sysetm, I have a cron that deletes the records from the summery table first and then insert the records in it again, Say Deleting 1 month records, and ...
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56 views

Design Payment System - Best way to track different payment types and reasons

I am designing a system to track incoming payments from external entities. Payments will be stored on tblPayment and take place in different ways, to mention some: 1) cash 2) cheque 3) credit ...
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40 views

Career Database Design

I am new in cakephp, I want to develop a simple career website, I have design the database, but I would like to show it to professionals and know if the structure is ok Jobs - id - job_title - ...
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39 views

What is wrong with my ERD?

I am trying to create a reservation/booking ERD. Is their anything wrong with my current ERD? It must show a supertype and subtype, and it must identify attributes for regular, weak, and associative ...
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53 views

Find the Minimal Basis

Suppose we have relation R ( A ,B ,C ,D ,E ) , with some set of functional dependencies, and we wish to project those functional dependencies onto relation S(A, B, C). Given the functional ...
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53 views

Promo Codes - should I create a separate table or add a code column to a join table for Students and Courses

I'm creating a promo code and invitation system and I want to understand the best way to structure the database to include the Promo Codes. This is what I have currently: User: has_many Courses ...
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50 views

Is there a way to check which views have data? Oracle 11g

I'm undergoing a cleanup process for a data mart design. However, I want to get rid of any views (in the design) which result in having 1 or less rows of data. Instead of manually going through ...
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283 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 ...
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18 views

App with ETL like operations - pull back small sets or one large set?

The problem Have an application that needs to provide back a result set from a normalized database into a single result sheet that is highly normalized for processing changes in excel. Must be ...
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139 views

Advice designing a stock management database

I am developing a webapp for my business, a mobile phone repair shop. The problem I have is I don't know how exactly to implement a way to manage the parts inventory. Here what i have now: ...
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37 views

Challenged with modeling a big DB

I'm tasked to develop a gaming web application system with relatively large database - it should hold the data about 300 million players, the orders/payment of each player - ~3B records - , and other ...