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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53
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Is there a name for this database structure?

Noob question, sorry if it's too basic for this exchange. We process a routine data feed from a client who just refactored their database from a form that seems familiar (one row per entity, one ...
15
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3answers
7k views

Schema design - best practices?

I understand the capabilities of SQL Server Schemas, but what are the best practices? Sure they give another layer of security, and provide logical grouping of database objects within the database, ...
16
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2answers
921 views

Decision criteria on when to use a non-dbo schema vs a new Database

I'm mostly an application developer but find myself having to do all the up-front database work for my current project (btw... its MS SQL Server 2008). As a first decision, I'm trying to figure out ...
3
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1answer
160 views

Constrains relationship

I have the following design. Each user has it's own contacts, it's own hosts and assign those to a domain which belongs only to him. I want to insure that the host you assign to the domain belongs ...
61
votes
5answers
7k views

How can a group track database schema changes?

What version control methodologies help teams of people track database schema changes?
11
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4answers
50k views

Copy complete structure of a table

Using some methods, when you create a copy of a table you lose indexes, PK, FK, etc. For example in SQL Server I can say: select * into dbo.table2 from dbo.table1; This is just a simple copy of the ...
3
votes
1answer
17k views

How can extract the table schema from just the .frm file?

I have extracted the data directory of mysql from a backup and need to get the schema from an old table, however it's a backup from a different machine. I have read a fair number of tutorials today ...
5
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1answer
3k views

SQL Server: hierarchy of permissions for schema?

We have several databases under development and I would like to start using SQL Server schemas for permission management and logical grouping of database objects. Under Schema Properties there is ...
3
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1answer
335 views

Storing created/retired dates for a large amount of different entities

In the db I'm working on now almost every entity has these 4 columns: CreatedDate CreatedBy RetiredDate RetiredBy Usually this is used for logging purposes, and for some of the entities the ...
3
votes
1answer
3k views

Permission for sequence in another schema

Postgres 9.3 Debian 7.0 I created a specific schema for a specific user and created a view in this schema for this user, so it's the only table he knows that exists. The problem is that this same ...
1
vote
1answer
200 views

Schema for multi-account database

I'm building an app which will have accounts for organisations leading to organisation.myapp.com subdomains for their account access. I'm putting together the schema for it and I have a few ...
35
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5answers
86k views

Difference between database vs user vs schema

I'm really confused with the terms database, user and schema. Can anyone explain how they are different from each other (if they are)? If they are same then, what are the similarities between them? ...
11
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6answers
18k views

Is there any good tool for making Database Design and Prototypes? [closed]

I would like to have a good tool for designing the Database Schema with all the tables, columns, data types and relations. Today I mostly do this with pen and paper but I would like to do it in a good ...
4
votes
1answer
171 views

Design for scientific data. Data table with hundreds of columns or data table with a generic value column and hundreds of rows (EAV)?

I am trying to improve the data storage in biomedical science lab where I recently started working. The existing workflow is atrocious, involving many differently formatted Excel sheets that all get ...
5
votes
4answers
13k views

Query to compare the structure of two tables in MySQL

To automate the backup process of one of my MySQL databases, I would like to compare the structure of two tables (current version vs old version). Can you think of a query that can compare two tables?...
13
votes
2answers
2k views

Schema-less/flexible + ACID Database?

I am looking at rewriting a VB based on-premise (locally installed) application (invoicing+inventory) as a web based Clojure application for small enterprise customers. I am intending this to be ...
12
votes
1answer
85k views

How to transfer data using expdp and impdp commands?

I'm Oracle noob, and my intention is to transfer all data and metadata from one schema to another schema within an Oracle database. I'm planning to use datapump expdp and impdp commands. I have ...
3
votes
1answer
841 views

mysql change schema on the fly

Recently I faced the problem that my Db became very huge and I cannot allow to myself downtime every time when I want to change the schema. This caused me to start looking for solution that do schema ...
8
votes
4answers
6k views

PostgreSQL: Creation date of a table

I've recently finished a project, during which many DB tables were created. Most of these tables contain temporary garbage, and I am looking for a simple way to list all these tables. Is there a ...
6
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1answer
3k views

How to migrate between schemas in bulk in SQL Server?

We currently have multiple databases but would like to combine them and, instead, separate our domain contexts using schemas. In MS SQL Server 2008 R2, how can I relocate all the contents of one ...
5
votes
1answer
228 views

ERD for a web development company

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 ...
0
votes
1answer
3k views

Db design for a quiz with variable number of answer choices, and each worth different score in a different category?

I'm working on a question/answer project and having a hard time coming up with a suitable database structure. Each question can have from 1 - "n" answers, and each answer is associated with one of ...
15
votes
6answers
3k views

Redgate SQL Compare vs Visual Studio 2010 Premium/Ultimate database project

I currently use the Visual Studio Professional Edition which has the database project as a project template, but some of its features are not available, for example Schema Compare tool. The schema ...
10
votes
3answers
421 views

How-to implement an entity with an unknown maximum number of attributes?

I am designing a baseball simulation program and I have run into a problem with designing the boxscore schema. The problem I have is that I want to track how many runs are scored in each inning. The ...
9
votes
1answer
2k views

Do schema changes “break” SQL Server 2012 AlwaysOn or are they handled transparently?

My organization is planning to adopt SQL Server 2012 AlwaysOn and I am trying to understand what impact (if any) it will have on our application upgrade process. We release application updates on an ...
1
vote
1answer
1k views

How To Hide Schema from user

I have DB with 2 schemas: A and B. B schema's procedures use A schema's procedures. I need to create user, which will not be able to see A schema. This user can use only B schema, but i want to let ...
8
votes
2answers
7k views

What is the usage of performance_schema in MySQL 5.5?

I have upgraded to MySQL version 5.5. There, I had observed performance_schema in the schema list. What is the usage of this new schema..? How can we monitor using this schema..? What are the ...
7
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2answers
14k views

Allow user to do anything within his own schema but not create or drop the schema itself

I have created a schema in SQL Azure and granted the following permissions to a database role: CREATE ROLE myrole AUTHORIZATION dbo; EXEC sp_addrolemember 'myrole', 'myuser'; CREATE SCHEMA myschema ...
5
votes
3answers
1k views

How to store many smallish time-series in a relational DB?

Input Data Multiple Tests Beds generate measurement data of various complexity. In it's most basic form, not considering any meta-data, one measurement on a Test Bed will be a small (1 - a few ...
5
votes
2answers
474 views

Should we create a schema per “project”?

This is a database where users create a 'project' and work on it. We have a table for project and various other tables that contain different attributes for project (multiple rows for each project ...
3
votes
2answers
1k views

Is it possible to get schema ID in another database without using dynamic sql?

I start with an object ID and a database ID. Inside a user defined function, I want to get the full name and ID of the database, schema, and object. How can I get the schema ID without using dynamic ...
6
votes
2answers
484 views

How many fields is too much for a primary key?

I am creating a table to store information about the placement of objects in a grid (game map). For example, I have a 10x10 grid and I want to store, in the database, that cell (5,5) has a blue box, (...
3
votes
1answer
12k views

How to transfer the ownership of the dbo schema in SQL Server 2012

I've accidentally given a user the ownership of the db_owner schema (using the check box in the UI as below) and now I cannot: Transfer ownership to another user Drop the user from DB (though I can ...
2
votes
1answer
185 views

Change tables from one user to another

I created some objects in MS SQL Server 2008 using SubSonic 3. It created them based on the user specified in connection string like: test_user.table1 but for some reason I am not able to test_user ...
1
vote
1answer
192 views

Data modeling with many attributes where few apply to each record [closed]

I'm pretty new to data modeling, so please excuse me if I've missed something obvious. I'm trying to decide on a schema (or possibly a DBMS) to work with some data where there are quite a few possible ...
0
votes
1answer
1k views

Select rows from table where each row refers to a different schema

I have customer table in public schema. And I have a schema named after each customer. Each customer schema contains different tables like portals, plugin, ... When I want to select portals used by ...
0
votes
2answers
2k views

Which schema is better for a shopping project? [closed]

I'm working on a business-to-customer project that has variety of product types. There are a few properties like name, description, brand_id that each product has but there are also many specialized ...
0
votes
1answer
167 views

What are the first necessary actions needed to help secure a database's schema & data? [closed]

This smells like an open-ended, opinionated, wiki free-for-all, but I'm not trying to make this a battle of opinions. It seems like there should be a good checklist out there for all to agree on ...
7
votes
2answers
141 views

What are the consequences of not specifying NOT NULL in PostgreSQL for fields which can't be null?

I have an application (data is stored in PostgreSQL), where majority of the fields in the tables are always not null, but the schema for these tables does not enforce this. For example look at this ...
5
votes
2answers
7k views

In Oracle how do you move a Schema to a different Tablespace?

I noticed that a Schema has been created in the USERS Tablespace but our local rule is that it should be in a Tablespace by itself. In Oracle how do you move a Schema to a different Tablespace?
4
votes
2answers
1k views

SQL: transfer database schema

If i want to transfer schema ownership to another schema i know that i need to use something like: ALTER SCHEMA destinationschema TRANSFER sourceschema.objectname; But how is it different from: ...
4
votes
1answer
757 views

SQLite3 simple database design question

I'm an ruby hobbist with no experience at all related to databases. I'm writing an application that is going to gather and backup tweets and blog posts (via rss feed) in an SQLite3 database. The ...
4
votes
1answer
3k views

Under what conditions are polymorphic associations used? What are the alternatives?

As I understand it, polymorphic relationships among tables in a database allow one table to have one foreign key that references many tables. I have found that tags are a common application of this ...
4
votes
2answers
534 views

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 ...
3
votes
2answers
1k views

DB2 (LUW) equivalent for Oracle “drop user cascade”

This question is related to creating and initialising test and development databases for an application that has the database running on LUW (linux-unix-windows) On oracle, we have an os user (on ...
3
votes
3answers
116 views

Schema for a lease platform

I have following tables: A room I want to lease (has user.id as ForeignKey) A users table for users who can rent it An availability table for time periods the room is to use with prices for that ...
2
votes
2answers
452 views

Please review my first thought-out attempt at a database schema

I am researching database design and theory and have finally made a thoughtful attempt at creating a schema that would be based upon SQL. I would like, if someone has time, to review my layout and ...
2
votes
2answers
1k views

PostgreSQL and default Schemas

Whenever I create a brand new database in PostgreSQL Maestro it creates the following list of default schemas: Now from my understanding Schemas are like folders for organization, etc. So the ...
2
votes
1answer
256 views

Using the output from mysqldiff.exe to transform database2 to match database1

This question is related to another I had asked earlier here: Passing passwords more securely to mysql utilities on the command line. I have recently been trying to use mysqldiff.exe, part of MySQL ...
2
votes
3answers
356 views

designing multiple tables while eliminating duplication?

As I'm working on an educational website, I'm facing a problem with my database design scheme - I can't find the correct design that eliminates duplication in the tables I'm creating. What I'm trying ...