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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Explaining the problem with a column of values from a non-mutually exclusive domain

I'm trying to convince the powers-that-be that their current database design is risky and inefficient. I'd like to verify whether my assumptions are correct, and I'd like help in finding technical ...
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45 views

create table in a different schema

I am trying to create a table on a different schema without using "create any table" privilege. I have an application user/schema. TABLESPACE_NAME USEDMB MAXMB ...
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31 views

Why default db privilleges are not applied on a new schema?

I have a user with all privileges granted by default in database properties. I create a new schema as postgres and table there. I expect that the user should have an access to this table but it looks ...
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25 views

Every “INSERT” query check a combination of column's records

Unfortunately, my mind has stacked right now and i would like to design a really simple DB schema. What i want? In a simple table, for instance Table1, there are two different columns, Series and ...
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21 views

Schema Design for multiple many-to-one relationships. of which exactly one should exist

Say I have table A, B, and C. B and C can both be related to multiple A's, but each A should have exactly one of either B or C related to it. Which database design is better: A: a_id, b_id NULL, ...
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34 views

Normalizing a folder schema

I've created a schema to allow creation of folders for customers. Customers Id Firstname Lastname StreetLine1 StreetLine2 City CustomerFolders Id CustomerId ParentId (NULL) Name Now as you can ...
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34 views

Database design for actions on some entity

I am making a todo list kind of a service. One todo list will have several items , that can be done/deleted/snoozed etc. Users can also add a new item to the list , delete an item etc. I want to ...
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61 views

Difference between contains and has in ERD

I am working on an ERD which represents the relationships between entities in a Web development company behavioral model. There I have entities like: Customer Service ----------- (like: web ...
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48 views

How unique are MongoDB _id fields?

I am trying to create a schema for documents and collections for a MongoDB database I am creating. I have read a few documents describing the _id field that is generated by each document upon ...
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189 views

Database design of Room Booking system in a Hotel

Intro and System Description I am currently designing a Database for a Room Booking system in a Hotel. Client fills a Form / Request with following information about Room: amount of people in ...
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52 views

Read-only user query in Oracle

I have been asked to create a read only user in a Oracle database 12c. The read only user must have read only grants only to the objects of select schemas, which I created and handed over. But now ...
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26 views

Design options for time series scientific data

I've been scratching my head over the last few days trying to find a solution that best suit my needs. I tried to think that what I want is probably not very different from what many others wanted ...
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22 views

Help creating database schema to build database off

not sure if this is the right area for a question such as this but I am looking to create a database for an IS warehouse who deliver laptops, desktops, monitors and other peripherals to different ...
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40 views

Seeking feedback on table relationships, general schema design

I'm designing a database for a business that sells tickets to a variety of events worldwide. The app will be built with Rails using PostgreSQL. Here's what I have so far, link to full size image ...
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62 views

Schema design for products with multiple variants/attributes?

I'm using MySQL. The idea is similar to shopify with a different concept, so users are going to add their own products with multiple types of variants and attributes. From all the research I've done ...
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50 views

Database schema for storing edits in the content [duplicate]

I want to store all the edits of a specific table. Multiple fields can be modified and for different users. I want to store all changes, taking in count that the number of fields that can be edited ...
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29 views

SQL Server 2008 running schema query without identifiable cause

I am analyzing the performance on login to an application and in particular making sure the database response is acceptable. In running just the simple Activity Monitor I can see that there are two ...
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22 views

Can I create a unique constraint across schema in Postgres?

I have a task that I am trying to accomplish where the email address is unique. The email address is stored in the a3.user table as user_name. CREATE UNIQUE INDEX ix_user_user_name ON a3."user" ...
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15 views

UML database schema based on the creteria

I have the following requirements to design a database schema (brief): A Graphic Designer (we will call them designer) gets a call from a client with a new job to design a logo. The designer ...
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20 views

How to find functional dependancies from a relational schema?

If only given a schema (table header, with primary key indicated), how do i find functional dependancies? My problem is that would not functional dependancies depend on the data stored int he table, ...
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55 views

Why not have Persons for every person in schema?

I noticed that a lot of database schemas often show like, "students" or "teachers" or "employees" or "passengers" or something to that affect. Why not have a schema where every individual is a ...
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24 views

MongoDB storage of multi-dimensional arrays

Using MongoDB 3.0.7 as the primary datastore. I connect to it using ReactiveMongo 0.11 on a JVM-based language. My question is: how well does Mongo store multi-dimensional arrays? For image analysis, ...
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354 views

Schema Migration: SQL Server Data Tools vs Liquibase and Flyway

This might seem like a stupid question, but I've been looking into open source solutions for schema migration, namely Liquibase and Flyway. However, my boss told me that SQL Server Data Tools (SSDT) ...
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54 views

Hard dba case [schema to store delivery prices for shops]

I want to make a database scheme which would allow me to fetch the delivery price for the different Shops basing on the delivery destination (Address/Region) and order value (price). Here is the ...
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39 views

Active Directory group as a schema in SQL Server

In SQL Server 2008 R2 we have a database that is being maintained by a team of developers. Each of them should have permissions to perform DDL operations such as adding a column or creating a table. ...
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50 views

SQL Schema Change; Modification of Existing Table vs Creation of New

We are planning the data schema for our project. Currently we have a table with classifications, but there is the possibility of a new classification in the future which would require a new field to ...
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48 views

How would you design a table for approval system between User and Sports Club

I am currently learning database modelling and struggling to model the following requirement. I have a user and sports_club table. User can only join a sports_club if three existing users of the club ...
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43 views

Compare order of columns between two databases

I have two postgres databases which should have an equal db-schema, but have not. I want to see the difference in the column order. Columns of table1 in Dev: id, foo, bar Columns of table1 in ...
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45 views

Single-Table vs. Multi-Table design

I'm trying to come up with a database schema which is going to be used for a social network similar to that of Facebook. Now for posts I have two schemas in mind which are as follows: Single-Table ...
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35 views

Default schema is ignored on SELECT

According to my understanding, a default schema should apply when issuing SQL statements on tables using unqualified table names. My problem is that the following statement fails, because the table ...
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21 views

DATE - Normalization, a multiple ranged query, multiple inserts and multiple update

I have a booking system, airbnb style. TABLES -> prices, house, available_date A house has available days and not available days, but sometimes the days have different prices. A weekend is more ...
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43 views

How can I layout a schema that will track monthly installments?

I'm pretty new to database design and have a beginner's understanding of SQL, mostly simple SELECT statements. I find myself in a situation where I have to create a system that will track monthly ...
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20 views

How can I organize this data?

I have been working in a system but don't know how to represent some of the data and its relations. There are three warehouses and a four shops working with the system and until this moment we can ...
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61 views

Finding the closure and super keys of a schema?

I am working on a problem in which I have to look at the relation R with schema R(w, x, y, z), and the three functional dependencies: w -> z ; x,y -> w ;z -> y For every non-empty subset X of ...
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How do I host and separate multiple projects on one Oracle Database?

From Difference between database vs user vs schema I'm trying to understand the concepts of the schema, user and database. My current understanding is you cannot create a schema separately. You can ...
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ER vs database schema diagrams

when i search the web for er diagram and database schema these 3 diagram types found but all are named under er diagram.i want to know what is database schema diagram and what is er diagram why all ...
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SQLite reference table question

I'm using SQLite and Python for making a sensor network database. I have a table holding the nodes: NODE, another 2 tables for sensor specification: SENSOR_TYPE ("Temperature, Humidity...) and ...
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56 views

How to design relationship for racing team trades?

I'm working on a fantasy racing team project. I'm having trouble laying out the schema when it comes to the team table and the trades. I think I have the race, driver, and result tables laid out okay: ...
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48 views

Permission in schema for user

I created a default database and created some schemas within this database. Created users for each schema, now I want to give full permission for each user in your schema only, how should I do?
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custom field related to usergroup and products

We need to create dynamically custom fields and store values related to each user or product in database we have product table related to category table and also user table related to usergroup and ...
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Possible to have duplicate fully qualified schema names with separate data in DB2 for z/OS?

We have several application teams that are looking to do a re-write of large legacy applications. This is mostly COBOL going against DB2 for z/OS (v11). The COBOL code was generated using a tool, so ...
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Variable Dimensional Data in Table

My application needs the ability to store data of variable dimensions. For example, it might have some three dimensional data, with values addressed by the vector [age, region, type], together with ...
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design of schema in mongoDB

I'm using mongoDB as my database. i have an record of 100 hospitals. To store all the information i'm designing schema of my database for that i've three solutions: i can create collection for each ...
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38 views

MongoDB schema for a news service

I would like to create a mongoDB database that would be very similar to how various news services store and display their data. The database would be queried by an android phone. Lets have a look at ...
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Asking SQL schema by FOIA

I've sent FOIA requests to various public institutions in my area. I'm only asking for the schema of the SQL databases their financial services might be using (column name for every table for every ...
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Comparison of MySQL Workbench model schema with existing database?

I need to compare the schema of a MySQL Workbench model with the schema of an existing database. My initial approach was to use the 'Forward Engineer SQL Create Script' option and compare its output ...
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90 views

Documenting SQL Server Database [duplicate]

I wrote the following (Quick and Dirty) script to document a database schema: Note - The relationships part came from another guys site (I just can't remember where). Does anyone know how to ...
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94 views

Functional dependencies applies to whole database or to a particular relation?

I am new to dbms. I saw a lecture video about functional dependencies. But I am confused a bit that whether functional dependency is a constraint put on whole database or on a particular schema?
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57 views

Store parameters of various types

I am a (poor, young) scientist working to develop a database to allow a project to scale up. I am experimenting with MySQL and have had very encouraging experiences so far, but I am still novice and ...
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PostgresSQL ignoring search_path when using input file

I have a SQL file generated using pg_dumpall, and I'm attempting to use it to restore a database with the -f option for psql (eg: psql -h 127.0.0.1 -p 8888 -U owner -f ~/restore_file.sql). My SQL dump ...