Questions tagged [inheritance]

For questions about extending a base object's features into a derived object.

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11 votes
2 answers
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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 ...
MVC Newbie's user avatar
11 votes
5 answers
55k 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 ...
m4rc's user avatar
  • 235
8 votes
2 answers
10k views

Partial unique constraint spanning multiple tables in postgres

To enforce partial uniqueness in postgres, it is a well known workaround to create a partial unique index instead of an explicit constraint, like so: CREATE TABLE possession ( possession_id serial ...
lpd's user avatar
  • 251
7 votes
1 answer
5k views

Performance issues with inherited tables and indices

I have a PostgreSQL database with a master table and 2 child tables. My master table: CREATE TABLE test ( id serial PRIMARY KEY, date timestamp without time zone ); CREATE INDEX ON test(...
umut's user avatar
  • 285
7 votes
2 answers
12k 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 ) ...
frenchie4111's user avatar
7 votes
1 answer
9k views

What is the purpose of "Schema Owner"?

If I create a new schema and set the schema owner to another schema, for example dbo, what is the meaning of that in regards to my new schema? Does my new schema inherit the same permissions from it'...
J.D.'s user avatar
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7 votes
1 answer
885 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 ...
JermaneBoggus's user avatar
6 votes
2 answers
15k 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. ...
user2486675's user avatar
6 votes
1 answer
3k views

Index is not used with table inheritance

I have a PostgreSQL 9.0.12 database with a master table and 2 child tables. My tables: CREATE TABLE test2 ( id serial PRIMARY KEY, coll character varying(15), ts timestamp without time ...
umut's user avatar
  • 285
5 votes
3 answers
8k views

Using table inheritance instead of mapping tables

This seems like a pretty common scenario: several types that all compose the same child type. This could typically look like so: -- 'name' is unique per parent record CREATE TABLE sometype ( ...
Dmitri's user avatar
  • 159
5 votes
2 answers
13k views

Best practise for polymorphic associations in MySQL

I have a MySQL database with 3 tables holding the main classes of data: companies (company_id) persons (person_id, company_id) loans (loan_id, company_id) Both a 'loan' and a 'person' belong ...
ratherBeKiting's user avatar
5 votes
1 answer
4k views

Polymorphic Association - is it bad?

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 CollectionId, ...
RobVious's user avatar
  • 151
5 votes
2 answers
1k views

Postgresql inheritance based database design

I'm developing a simple babysitter application that has 2 types of users: a 'Parent' and the 'Babysitter'. I'm using postgresql as my database but I'm having trouble working out my database design. ...
Jdruwe's user avatar
  • 153
5 votes
1 answer
3k views

Transfer row from 'parent' to 'child' without creating duplicate and without knowing all 'parent' columns

I want to set up a database with different schemas that correspond to different data-entry systems. There needs to be a “master” (administration) schema with a “parties” table, and multiple other ...
user2437443's user avatar
4 votes
2 answers
3k views

Abstract classes in SQL Server. Are they even possible?

I have a very specific question that I am surprised no one has yet asked. It involves a concrete class model and SQL Server 2016 DDL. The main point is: In my model, some classes inherit from a base ...
Petros Apotsos's user avatar
4 votes
2 answers
1k 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: ----------------- ...
Saeed Neamati's user avatar
4 votes
1 answer
2k 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 ...
Zalom's user avatar
  • 143
3 votes
1 answer
4k views

Postgres 9.5 foreign table inheritance not using indexes

In PostgreSQL 9.5.0 I have a partitioned table that collects data by months. I tried to use the new PostgreSQL feature of foreign table inheritance and pushed one month of data to another PostgreSQL ...
Dzmitry Nikitsin's user avatar
3 votes
1 answer
1k 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 entity,...
csblo's user avatar
  • 131
2 votes
3 answers
568 views

Record inheritance in mySQL

I have been struggling with this for a little while. I want to have a set of calendar records. The top level will apply to a large group; the next level will apply to a sub-set and the final level ...
Richard's user avatar
  • 21
2 votes
1 answer
363 views

Inheritance of "dictionary tables"

(In case this matters: I'm using SQLite) My silly little database has a surprising number of tables with identical structure: CREATE TABLE GTag ( ID INTEGER PRIMARY KEY NOT NULL, ...
Vestin's user avatar
  • 23
2 votes
2 answers
4k views

Postgres inherit from one role and not another

I'm a little new with postgres but have a decent understanding of roles. What I have are users that inherit from their normal "data_analyst" group. This group is used to manage all data analyst users ...
Pistol Pete's user avatar
2 votes
1 answer
815 views

Database relationship inheritance [closed]

I have a vehicle sales store. In my store I sale many kind of vehicles for example cars and boats. And I would like to keep track of the sales. My vehicles has some attributes as: Arrive on store ...
Lin's user avatar
  • 123
2 votes
2 answers
491 views

DB model strategy to override field value

We have to store some dynamic configuration in JSON format in DB. There would be some default configuration, and it can be overriden per account. Can someone help me with the strategy to store such ...
sidgate's user avatar
  • 131
2 votes
1 answer
96 views

Finding a good DB design for my project

I've posted this on stackOverflow but this might be a more suitable place. I'm really struggling to find a good DB design for my project using SQL server. I've already implemented a few models which ...
LiranBo's user avatar
  • 123
2 votes
1 answer
530 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 ...
user2759920's user avatar
2 votes
1 answer
55 views

Preserving foreign key properties when using Class Table Inheritance (or alternatives)

Imagine I have a table events, which outdoor_events and indoor_events inherit from. I have activities then outdoor_activities and indoor_activities. Assume it makes sense for outdoor and indoor to be ...
thshea's user avatar
  • 198
2 votes
1 answer
1k views

Postgres natively partitioned tables - adding extra child columns

With Postgres native partitioning, can you add extra columns to a partition of the base table? Like: CREATE TABLE item ( tenant_id bigint NOT NULL, item_id bigint NOT NULL, kind text NOT ...
Joe's user avatar
  • 179
2 votes
1 answer
378 views

Correct way to join row in parent table to row in one of several children tables

I have a parent table product, and several children tables like phone, tablet, smartwatch etc. The parent and children have 1-1 relationship. This means that for every row in parent table, there will ...
Abdul Wasae's user avatar
2 votes
1 answer
218 views

Designing an extensible authentication system

I need to design an authentication system, where different type of authentication schemes may exist. At the end, I should assign a passphrase (access token) to the user. I have several authentication ...
Buğra Ekuklu's user avatar
2 votes
2 answers
478 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 ...
Justin Grant's user avatar
2 votes
0 answers
233 views

Is it possible to drop inheritance from the parent table (top down)?

Our system uses inheritance on two levels: master child_level_1 child_level_2 child_level_2 child_level_2 child_level_1 child_level_2 child_level_2 child_level_1 child_level_2 The idea was to ...
Jesse's user avatar
  • 121
2 votes
0 answers
770 views

Is it correct to model a specialized table using a foreign key whose referencing attributes are not also forming its primary key?

In the process of designing a database model, I would like to implement a Class Table Inheritance pattern in a way that does not seem common at first. I would like to know if it is a correct ...
soliz's user avatar
  • 293
2 votes
0 answers
276 views

PostgreSQL database re-design considerations

We have a 2TB PostgreSQL database, which contains two groups of tables that account for about 90% of the storage used. These two groups can be loosely described as 2 big tables partitioned, the first ...
Gonzalo Vasquez's user avatar
1 vote
1 answer
5k views

PostgreSQL: Multiple Inheritance tables (one child to two parents)

If I have a base table and 2 or more tables that inherit from it, child1 and child2, I can insert a record into a child table and it shows up in base as you would expect. However what I want to know ...
FireLeopard's user avatar
1 vote
1 answer
2k 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 ...
Bart Calixto's user avatar
1 vote
2 answers
1k views

Views that inherit a table and syntax in PostgreSQL

I am getting a syntax error but don't understand what is wrong. I am using a reference here. This is my sql-snippet: CREATE OR REPLACE VIEW stipa_test.stipa_view AS ( SELECT * FROM ... ...
Michael's user avatar
  • 139
1 vote
1 answer
2k 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 ...
mr5's user avatar
  • 127
1 vote
1 answer
191 views

Class Table Inheritance combined with running searches and paging

Assume we have tables similar to the following: CREATE TABLE Base ( ID int, Type varchar(20), Col1 varchar(255), Col2 varchar(255), AddedAt datetime2 ); CREATE TABLE Sub1 ( ...
deadwards's user avatar
1 vote
2 answers
2k views

Deleting rows from child table without deleting from parent [closed]

I have 2 tables, connected with inheritance. I want to delete some rows from the child table. The deletion part works but it deletes rows from the parent as well: CREATE OR REPLACE FUNCTION ...
Dionisis Kotzaitsis's user avatar
1 vote
1 answer
720 views

Improve PostgreSQL SELECT performance in a parent table (inheritance)

I have a PostgreSQL 9.2 database where each account has a schema, like below: My_Database |-> Schemas |-> AccountA |-> AccountB |-> AccountC |-> AccountD |-> ...
Marcio Mazzucato's user avatar
1 vote
1 answer
387 views

Can I improve the way pg_dump exports inherited tables?

Given a postgresql 12 database with some table inheritance, and the child table adds no additional columns: CREATE TABLE parent ( id integer NOT NULL PRIMARY KEY, name text NOT NULL ); ...
James Healy's user avatar
1 vote
1 answer
917 views

user security inheritance in SQL Server 2016

I'd like to build a bunch of new databases (several dozen) in SQL Server 2016. However, I'd like all users to access a single database (called SECURITY for now), and apply security to that one ...
JustBeingHelpful's user avatar
1 vote
1 answer
483 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 ...
fbonetti's user avatar
  • 111
1 vote
2 answers
386 views

Oracle MV requires object type to be defined as FINAL?

I want to create an Oracle 18c materialized view (MV) on a table that has a user-defined datatype called ST_GEOMETRY: The MV would do a COMPLETE refresh on a schedule — on a local table. Some info ...
User1974's user avatar
  • 1,457
1 vote
0 answers
917 views

Implementing a graph-like design on postgresql using CTEs and inheritance

This question is about attempting to model/design an elementary graph-like database within postgres. The starting point is that graphs have: Nodes Nodes have properties Node are connected by (bi/...
ahron's user avatar
  • 793
1 vote
1 answer
652 views

Django Multi Table Inheritance and Preserving Child and Child History

Place can have many different one to one fields, that’s why it can have bookstore, restaurant, and hardware store. But can the same place be both a bookstore and a restaurant at the same time? Now if ...
Malik A. Rumi's user avatar
1 vote
0 answers
1k views

PostgreSQL doesn't use index on inherited tables

I have two tables in PostgreSQL 9.4.5 deployed on Amazon RDS: an append only, weekly partitioned, All Positions table. These store all position readings from about 100,000 sensors. There are about 50 ...
Justin Wong's user avatar
1 vote
0 answers
282 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 ...
abalter's user avatar
  • 127
0 votes
3 answers
4k 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 ( ...
Ben's user avatar
  • 257