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

learn more… | top users | synonyms (4)

0
votes
0answers
35 views

Mongo Schema for large time series data sets

I'm not a DBA but a C# developer, my experience so far is with MS SQL, so please keep that in mind. I am trying to design a scheme to store sensor data and have it organized. Each TestRecord would ...
0
votes
1answer
24 views

Checking for BCNF in a relational database through FDs?

Okay so I know that for BCNF, when listing all non-trivial FD's that everything to the left has to be a candidate key. So I have this relation: Person(Id, TFN, Name, Phone) Where Id and TFN(Like ...
0
votes
1answer
51 views

Raise Multiple Exceptions Postgres

I am using Postgres 9.5, and I am trying to create exception handling in a stored procedure/function. I can't quite figure out how to raise the error should any of the 'INSERT' statements fail. If ...
0
votes
0answers
33 views

DB design: Store data VS more complex DB changes

This is my current DB structure. -- -- Table structure for table `prods` -- CREATE TABLE `prods` ( `prod_id` int(11) NOT NULL, `prod_name` varchar(255) NOT NULL, `prod_aaa_id` varchar(255) ...
0
votes
0answers
61 views

Using the same tables for multiple many to many relationships

I currently have a project where I need multiple Many to Many relationships some of them are roughly and I started to wonder if using an extra column on the table to specify the table it's related to (...
0
votes
3answers
108 views

Best name for link table [closed]

I was wondering what the best name for a linked table in this situation (or any) would be. I've searched for this, but could not find any concrete examples. For example, I have the following tables (...
0
votes
0answers
37 views

Should I break up this MySQL table?

Existing table (more or less). It has about 1 million rows: id article title stage 1 zipfile name stage 1 delivery date stage 1 checked date stage 2 zipfile name stage 2 delivery date stage 2 checked ...
0
votes
0answers
25 views

improve performance with schema design, a lot join

I'm making a custom cms system for my client, with postgresql, nodejs ... have problem with slow performance issue, when doing select data . (and it is still on localhost/mac nginx and just few data, ...
0
votes
0answers
30 views

Intergrated or seprated ? One row with multiple data or multiple rows with one data [duplicate]

I'd like to create a Friend system like facebook What type of DB design do you suggest ? 1. id | userid | friends_id ---------------------------------------------------- 1 ...
0
votes
0answers
24 views

MySQL Design for bulk inserts

Consider the following table structures as below, these tables can go beyond millions records received_goods rg_id int(10) PK (auto_increment), name varchar(128), ... storage_details rg_id int(10)...
0
votes
1answer
25 views

Access Web App query 3 Tables with aggregatios - Need a workaround

I'm designing an Access 2016 Web App for inventoring our computers. The problem I have is with a query where I want to get the CPUCore-amount and RAM-Amount for each PC. The computer-value in RAM ...
0
votes
0answers
22 views

Modeling question - Meta and instance

In a relational DB I'd like to model this: every customer_type has one module_set (1:1) a module_set has several modules (1:n) every module is different, and the user can activate them & reorder ...
0
votes
0answers
26 views

how to remove create relation foreign key in phpmyadmin

I am having problems in PhpMyAdmin Designer Section. I'm not able to do anything like I cant even move them to see their relations. When I try to click on tables the screen shown in picture appear ...
0
votes
1answer
26 views

database design help with multiple table relationships

Been scratching my head on how to set this up and looking for your help. Trying to create an API and not 100% how my tables should relate to one another. So lets say I have users, food, and food ...
0
votes
0answers
68 views

Which NoSQL Database is best suited?

I have been reading a lot of blogs trying to determine which NoSQL database would be best. I am looking at moving from file based (xml) storage to using a database. The application will be storing ...
0
votes
0answers
29 views

Mongodb database design

I'm planning to implement this schema in Mongodb, I have been doing some readings about schema design, and the notion was whenever you structure your data like a relational database you must be doing ...
0
votes
0answers
25 views

Time Series on Postgresql

I am developing a software that have a dataset time series like this: id_equip, Timestamp, Double v1, ..., Double v30 The size estimate is 5.000.000 rows by year and the time of response is very ...
0
votes
0answers
16 views

Product Features table for No Sql Databse

I want to design database to save products features. Actually i want to store all features of mobile given on this link http://www.gsmarena.com/samsung_galaxy_j7-7185.php After search on google i ...
0
votes
0answers
53 views

Normalized college database desgin

I am trying to create a college course database. The College offers UG and PG courses in various departments. Departments include program streams like MCA, MBA, and Engineering. MCA courses may be ...
0
votes
0answers
26 views

Modeling a database with UML scheme and every type of relations

Good evening! This is my second database designing, the first one can be found here. I want to find the relational scheme of bridal registry database given in the following French UML graph: I ...
0
votes
0answers
18 views

SQLite text columns

When having a table in SQLite that has a TEXT data type, is there any implication if the length of the contained string differ significantly?
0
votes
1answer
45 views

Foreign key as part of composite primary key or not?

I'm designing a relational database. This is what I'm trying to design: I will have production orders and products. A production order will have one product, but a product could be on zero or more ...
0
votes
0answers
18 views

Data Modelling of product and product variations

I want to model product and product variations using mongodb (mongoose) I am really confused with how shall I model both I need to add stock and price to variations. Variation can be of anything (not ...
0
votes
1answer
35 views

DB Design - 1 column for each dataset OR dataset_name AND dataset_value?

I am creating a database table for storing numeric time-series data sets regarding cities that will be accessed via a web app. Primarily annual, quarterly and monthly data will be stored in it. ...
0
votes
0answers
19 views

Trying to fix collation mess

In our MySQL database we have set several collations. e.g. Connection collation utf8_unicode_ci Server configured default collation utf8_unicode_ci Database default collation utf8_general_ci Table ...
0
votes
0answers
5 views

What is the advantage of using Spring beans for DB connection?

I am new to java spring and I'm just wondering if placing the db connection in spring beans has a great advantage?
0
votes
0answers
37 views

NEXT VALUE FOR SEQUENCE inside a CASE Statement

I want to use a new SEQUENCE each year (See here: 'Id' with the format: YYYYNNNNNN with the NNNNNN part restarting each year ) However you can not use NEXT VALUE FOR inside a CASE statement. ...
0
votes
1answer
26 views

logic/design for storing achievments and progress for users

I have a game with a databse of users, I now want to implement unlockable achievments in my game. How would I best go about saving this data for each user? I am still fairly new to using a database. ...
0
votes
1answer
57 views

Convert OLTP database to OLAP Datawarehouse

(http://imgur.com/p8Gy67E). Basically I need help to convert that OLTP Model to Data Warehouse in order to be used for further OLAP Cubes. I understand well the difference between the Star Schema and ...
0
votes
0answers
23 views

Restrict Front Ended User access to Form entry only

I have a front end database that I want to restrict user access to only enter data into a form. I do not want them to be able to scroll through other entries via the form. How can I restrict this in ...
0
votes
0answers
19 views

Help choosing between one and two tables for manually entered and auto generated items

I'm designing a database that merges a legacy system with a new system, all for the same customer. For the new design I need some help whether to use the same table or two different tables. ...
0
votes
1answer
38 views

Creating a pseudo email database

I am creating a database for Job offers website between Employer and Applicants that required sending Email between the two in MSSQL. Let's say I have 3 tables like these: Employer ID int idetity(1,1)...
0
votes
1answer
64 views

Database design for a lot of rows with data archive

i'm new to database design on larger scale. I have some knowledge and experience with MySQL but now i have some performance issues. Currently i'm using MySQL with 3 databases: History Snapshot ...
0
votes
1answer
58 views

Searching from Database having billion records, which database should i use [duplicate]

We are having 1 billion phone numbers and we have to search them against numbers which we send for promotion to filter out which are not promotional registered. That is we have lets say 1 million ...
0
votes
0answers
15 views

What is a fast way to calculate counts and sums?

I have the following data: A journey which contains this info: - a geohash (to identify the location) - a journey_id - whether this was the start or end of the journey - the cost of the journey I ...
0
votes
0answers
29 views

Does an exam entity in a student information system depend on the department or the student?

I have made an ER Diagram for a student information system where I have the following entities: Student Department Course Administrator Exam Attendance I'm having trouble determining whether Exam ...
0
votes
1answer
34 views

Which isolation level do I need?

I've read a lot of articles about Isolation levels, but I'm confused which one to choose for my MySQL 5.6 database. This is my situation: Let's say I have two group of users: Group A (...
0
votes
0answers
41 views

Registration Schema Implementation

I'm building an online app that is going to handle reservations. Individuals making reservations can make one for a single day or multiple days. I have come up with two schema and cannot see much of a ...
0
votes
0answers
23 views

Address database scheme - multiple links

I am currently building a databse scheme for a small company. But at the point doing it I figured out that my attept will be unacceptable due to the ability that one action will affect multiple ...
0
votes
0answers
23 views

Database design for efficient read queries given lots of writes

I have a PostgreSQL database, and an application which receives around 200 requests per second. Each of those requests contains a message with an identifier representing a journey id, a timestamp, ...
0
votes
0answers
79 views

How could I improve speed of fetch in Oracle?

I've got a table of taxi GPS trajectory records with approx 60 million rows, including date, time, ID, longitude, latitude, speed, bearing etc., which were imported from .csv files with setting each ...
0
votes
0answers
30 views

How to store general information about an entity

I am designing a database to store data relating to management of a school. I have tables representing the sorts of things you would imagine: Students Carers Invoices and so on. One feature I wish ...
0
votes
1answer
28 views

Best way to apply a “friend system”-like table? [duplicate]

I am making a website that has multiplayer games like chess, poker, etc. Users will be able to add friends. I was thinking about how could I make this in a DB, and I thought of two methods: 1 - ...
0
votes
2answers
45 views

One connection vs multi connection

I'm redesigning my client's website in order to add about 16 mini sites for their web site. It's a website using PostgreSQL. And my question is: Performance wise, what is the better database design: ...
0
votes
1answer
29 views

How to show the Join with Crows Foot Notation

I could be barking up the wrong tree, but I'm trying to illustrate not only what the relationship is between entities, example, Customers shop in many stores, but also how to join the two entities. ...
0
votes
1answer
46 views

Should a TeamMembers table have a relationship with the Student Table or the Enrolment Table?

I'll keep it nice and short and simply link to the ERD: Users can be assigned a role, one of those is student. So for the sake of this, Students are the same as Users! A Student can be enrolled in ...
0
votes
1answer
35 views

Question regarding database design

I want to store data of customers and employees. What I am having trouble deciding is what is the correct thing to do: a. Option a: Two tables - Customer and Employee b. Option b: Three tables - ...
0
votes
0answers
27 views

Microsoft Access Form's Combo Boxes Help

I have a database in access and I am creating a form to enter transactions for investors in our hedge fund. The form is supposed to create new records in the table tblTransactionsAccrued. I created a ...
0
votes
0answers
40 views

primary and foreign keys used in object-relational table

Currently I am designing an object-relational database based on an existing relational database with multiple primary and foreign keys, and was wondering if it is OK to use primary and foreign keys in ...
0
votes
0answers
15 views

How to set a Totals column based off sum of another table

I am currently developing a web app with the following tables: QuoteHeader Id etc... QuoteLineItem Id QuoteHeaderId TotalPrice etc... I'd like to have a column in QuoteHeader that shows the ...