Database Administrators Stack Exchange
Database Administrators Stack Exchange

Questions tagged [schema]

A schema of a database system is its structure described in a formal language supported by the database management system (DBMS) and refers to the organization of data to create a blueprint of how a database will be constructed (divided into database tables).

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Example where schema are better than multiple databases

In several database systems (e.g., PostgreSQL and MS SQL Server) there is a concept of schema. There are many questions out there asking what schema are and how they are used; here is a good one. Usually the answer boils down to "namespace" and…
rlandster
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Need database of categories for products and services

Need to develop a database schema that associates products and services into industry-standard categories. I know that both the schema and data are out there, yet I'm not finding it. There are databases that list products (and contain millions of…
C. Scott
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What is the difference between logical schema and physical schema?

While going through Database architecture I came across Schema's . I am very much confused with: Logical schema Physical schema How these two schema exist in the Database? How can these be manipulated according to need? How Logical schema and…
nitesh.kodle123
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Unique time range or database schema for a scheduling system

I'm having to design a table which contains scheduled times for media to be displayed. These scheduled times should not overlap. In my SheduledSlot table I have: id integer PRIMARY KEY begin datetime(or integer for SQLite) end datetime(or…
Edward Williams
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Physical vs Logical data independence

I am new to information systems and was working on a homework. I am not sure of the difference between physical and logical data independence. What is meant by physical and what is meant by logical ? I keep thinking of physical as like a harddrive…
Kong
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Best practice for database where the values can't change

Suppose I have a table Inspection with a field for Place (the location where the Inspection occurred). The field is a foreign key to a Place table, where each place has a Name, among other things. The Place names can change over time (for instance…
Jamie Forrest
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Having multiple refs in an intersection table

I have two tables, BOOK and JOURNAL. I want to store their authors in an intersection table called AUTHORS. Is it acceptable practice to have mulitple reference id columns (kind of FK's I think) to other tables i.e. BOOK and JOURNAL? This is to…
Vidar
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db schema for a object with multiple foreign key tables

I have a question table which contains question_id, question_text and choice_type_id ( say freetext, binary choice and multiple choices ) Now, the question table (which has question_id, question_text, choice_type_id) has a foreign key to the choice…
R1234
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How to differentiate between class and attribute

I have this problem: Library has books, VDOs, CDs Journals. It gives loan to users. Books and Journals can be referential which cannot be loaned out more than 2hrs and non-referential which can be loaned out for 2 weeks. user have ID and name and…
DBAStudent
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To implement a facade DB table or not? [pics]

Does it make sense to normalize a schema with tables that only serve the purpose of logically separating parts of a system? Below are 2 example schema with what I am talking about. (sorry about the titles being hard to read) One with the…
ryand
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Why can't the schema owner create a new table?

I have a DB user called STANMAN which owns the STANMAN schema. When I try to create a table as STANMAN, it says STANMAN has insufficient privileges. How could a schema-owner not already have sufficient privileges? Naturally, when I try to GRANT…
MLF
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Could you help me evaluate my database schema for my pet project?

I'm planning to make a pet project about a shop with a cart to consolidate knowledge into practice. I'm pretty new to databases and would like to hear from you about how I can improve my data schema. I hope you understand (._.)'
AMoralt
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The best approach to abstract the item in storage database (theoretical question - no code required)

I am struggling to find a better approach on the following topic and would appreciate any advice. 1. Description: Database purpose - warehouse storage. There are a couple of entities such as: t_resource (from what the product made). t_product (the…
rey4eel
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Can database administrators change physical schema?

I was reading the Chapter 1 of the 7th edition of Database System Concepts and ran into this: • Schema and physical-organization modification. The DBA carries out changes to the schema and physical organization to reflect the changing needs of the…
heretoinfinity
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DB Schema for online market

I'm just search for advice. I have . Every Product type has its own set of characteristics. The Big problem is when someone add new Product type, aslo need create new table with product characteristics. I can see only one solution without DBA,…
pogody lea
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