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5
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1answer
35 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
11 views

Dimensional Model for inheritance in dimensions

How are dimensions typically modeled in a dimensional model if one dimension logically inherits from another dimension? For example, assume I have an Employee dimension and a Driver dimension, where ...
4
votes
2answers
160 views

Conceptual ERD Multi-table many to many, or possibly recursive?

I'm creating a conceptual diagram [yes, I know I've included attributes and keys - but this is just for me to consolidate what I'm doing whilst learning] -- so please treat it as Conceptual with the ...
1
vote
0answers
21 views

Alter schema of Access 2013 database with linked table

I'm trying to change the schema of an Access 2013 table. I want to lengthen some of the text fields. When I change the schema and try to save I get dialog with Operation is not supported for this type ...
0
votes
1answer
147 views

Enhanced ER Model Supertype / Subtype modeling issue with inheritance and recursion

Before posting, I have looked for a good solution on internet and I have coined this post for 3 days in row and trying to think through it prior this post. So if I have missed something or got it ...
1
vote
2answers
184 views

How to enforce data consistency across one-to-one relationship in an inheritance hierarchy

Consider this design for a typical school database: Person: ----------------- FirstName LastName SocialSecurityNumber Phone Email Student: ----------------- Grade Teacher: ----------------- ...
0
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3answers
35 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, ...
0
votes
1answer
76 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 ); Is there any way to query the parent table, such ...
1
vote
1answer
83 views

Will switching from Concrete Table Inheritance to Single Table Inheritance improve the performance of my queries?

I currently have an application that allows people to view and share 10 different types of posts (ex SportsPost, WorldNewsPost, TechnologyPost, etc). All posts types are conceptually the same, but ...
0
votes
3answers
220 views

Can i have one foreign key to both parent and it's childs in postgresql?

I want to have a foreign key to reference table and it's children. Here's how I tried and failed: CREATE TABLE parent ( id serial, CONSTRAINT parent_pk PRIMARY KEY(id) ); CREATE TABLE child ( ...
0
votes
1answer
46 views

PostgreSQL migrate data from one table to another (which inherits the first one)

I have a table "company" and another named "school" ("school" table inherits "company"). Most of the data is community generated and sometimes a cleaning is needed. I would like to be able to ...
2
votes
1answer
135 views

Inheritance or lot of relationship?

I have to transpose a class Diagram into a Physical Data Model (more precisely MySQL database structure). In my class diagram, I have a lot of entities (A, B, C, D) which inherit from an other ...
4
votes
4answers
12k views

Insert into select into multiple related tables using INSERT_IDENTITY

Okay setting the scene. I have three tables, (Table1, Table2 and DataTable) and I want to insert into Table1 and Table2 using DataTable as source. So for every row in DataTable I want a row in Table1 ...
0
votes
1answer
200 views

Inheritance discriminator column better int or varchar or enum?

What is the best practice for storing a discriminator column ? Does it make any difference ? Any pros/cons of using one over the other ? I am using MySql with Entity Framework but the question goes ...
0
votes
0answers
101 views

PostgreSQL and Single Table Inheritance

I read about STI (Single Table Inheritance) and like the idea. Does PostgreSQL handle 95% NULL values in some columns if I have about 1M rows well? Does it impact performance if there many columns ...
0
votes
1answer
155 views

Foreign key double inheritance SQLITE

I'm designing a domotic system database and I'm trying to figure out how to represent two foreign keys. This is the cardinality I want. Consider 1...N Areas (rooms, halls, kitchens, etc.): Area 1 - ...
3
votes
1answer
152 views

Is this a step in the right direction for normalization? SQL 'inheritance' and Many-to-Many relationships

Context: So, this is kind of a compound question, but they go together, and definitely wouldn't make sense split up into separate questions. I've been working on a new database for what will end up ...
1
vote
1answer
540 views

Cannot add or change records

I'm designing a database structure wherein I like to apply the concept of inheritance. There's a base tables and derived tables in which the relationship is one-to-one. I'm quite new as of how could ...
0
votes
1answer
41 views

Table join inheritance

I create db with Person, Client, Employee, Manager, Developer. I'm interested what is the best way to put the data in tables. In which cases should programmer unite Client in table hierarchy with ...
1
vote
1answer
600 views

Polymorphic Association - is it bad? [duplicate]

In the following schema: Collections Upvotes Reports Upvotes Reviews Upvotes I'm tempted to have a single Upvotes table with a single "entityId" column that stores either the ...
0
votes
1answer
149 views

Altering a parent table in Postgresql 8.4 breaks child table defaults

The problem: In Postgresql, if table temp_person_two inherits fromtemp_person, default column values on the child table are ignored if the parent table is altered. How to replicate: First, create ...
0
votes
1answer
44 views

Mapping and Inserting Values into a Specialized table

For a system i'm designing,i have one parent entity,Computer Computer(computer_id,computer_processor,computer_hddrive,computer_memory); A computer can be of two types,Desktop and Laptop,each having ...
0
votes
1answer
223 views

Partitioning table with billion row

I have a big table referenced by other tables and need to split the table on several parts. I create table by CREATE TABLE product_part0 () INHERITS (product); Move some rows to product_part0 by ...
1
vote
2answers
1k views

How to drop inheritance?

I am new to PostgreSQL. The situation I have is someone created a child table inherits from the parent table. And dropped the child table. But the parent table still has the "down arrow" sign on it. ...