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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MySQL Space efficient way of storing indexed key-value pairs associated with table

We're storing transactions in an accounting system using two tables, one contains the general description of the particular transaction (the other contains the entries, one for each account - which ...
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2answers
54 views

Best design for a many:many relationship issue

We have three types of entity, each with their own table: table:A(a_id), table:B(b_id), table:C(c_id) Each of these entities can have any number of email addresses and linked Twitter accounts. ...
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48 views

Schema & Database Role Permissions Issue

I have a Schema and a Database Role. An Active Directory member is added to the Database Role. I grant the Role Select permission on the Schema. Control permission is denied on this Schema. However, ...
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13 views

Reducing schema to shrink real-world data to a functional subset

I work with two editions of a shipping product; call them "A" and "B". Both use similar a database schema, but edition "B" has a strict super-set of the schema (and features) used for edition "A". ...
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3answers
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How do I list all schemas in PostgreSQL?

When using PostgreSQL v9.1, how do I list all of the schemas using SQL? I was expecting something along the lines of: SELECT something FROM pg_blah;
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3answers
2k views

Is there an Open Source Metadata Management Solution? [closed]

Is there an Open Source Metadata Management Solution? I'd like to create a Metadata Repository that will hold the details of the metadata of database schemas, tables and data items of hundreds of ...
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1answer
209 views

Automatically generate ALTER TABLE to syncronize schema on PostgreSQL

i Have 2 different database schema in PostgreSQL sql file from pg_dump, is there automated way to generate alter table commands so it would be in sync, without inspecting one by one? this is the ...
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1answer
304 views

Shopping cart schema with multiple product tables

I have a shopping cart table used to store customer id and product id of their chosen items. However I have multiple product tables, for example cars, books, houses. I started out with one table but ...
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1answer
76 views

Multi tenancy by schema - Deny access to another tenants [closed]

In a multi tenant environment, where the multiple tenants are in the same database and a schema is used to separate each one of them, how can I create a database user (MS SQL SERVER) for each schema, ...
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2answers
71 views

Store extra, optional information about any entity [closed]

I've done a bit of reading but haven't found anything related. This must be widely discussed, so it's most likely my fault. I've got a relational database with a number of different tables, each ...
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0answers
45 views

Should I be worried about duplicate entries in the Oracle all_dependencies table?

I think there are some problems with object relational functionality in Oracle 11g (and some earlier versions). We have a purely relational mapping ready as it is easier to handle, but need to support ...
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3answers
328 views

Database design for bookmark system

I am creating a bookmark system where people can save their bookmarks. Each user has its own personal page with bookmarks. A bookmark should have atleast one tag and max five. Each user can create ...
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0answers
79 views

Schema for yearly data models

I am developing a school management system. Most data will not be reused after the end of the school year. I am contemplating using schemas to separate data in various school years, however I am ...
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2answers
767 views

Is it bad idea to create foreign keys on the tables in a different schemas in the same database for big applications?

I am working on the transfer a big pl/sql web-based application to the dedicated server. This application is located in one schema with 70 packages of programm code. This application was made ...
1
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1answer
278 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 ...
5
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1answer
689 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 ...
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2answers
110 views

Accept null value on parent column in multipart relationship

EDIT: I've come up with one poor solution (below) that requires some denormalization, but does avoid the risks of UDFs in CHECK constraints. I would appreciate your help if you have a better answer. ...
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2answers
359 views

How to create a blank version of a PostgreSQL database

I've been using pgAdmin to create a database and test it. I'm at a point now where I need to install this db on different servers. I've been using pg_dump to do this and I've been able to muddle my ...
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2answers
187 views

Postgres sequence usage

I have an Postgres database with two users: dev and junit. Junit and dev objects are dropped and created regularly. They both have the same objects unshared for tables, however, sequences are shared, ...
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1answer
274 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 ...
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0answers
82 views

Cloning Postgres schema/tables across multiple servers

I'm working on a project that has databases across multiple servers, with one server for each business client. The project has some identical 'base' tables that are present in all the databases (for ...
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1answer
507 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 ...
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2answers
216 views

Oracle - Is it possible to maintain transaction across multiple schemas?

I got this database in oracle which includes 4 schemas. Each schema represents a logical layer. Each transaction (Stored Procedure) in the upper layer breaks into a couple of transactions in the lower ...
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1answer
150 views

Should I extract / normalize the mailing address despite requirements limiting number / type of addresses?

I currently am working on a contacts application (similar to Outlook contacts combined with eVites and LinkedIn). The requirements for the application are to limit the addresses (and phone / email ...
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1answer
131 views

Data Sync between servers with different schema in SQL Server [closed]

I have two servers 2008 R2 and 2005. The e-commerce site has been running with 2005 Server i has migrated 2005 server data with modified data schema to 2008 R2 from yesterday's date of data. My client ...
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1answer
1k views

Candidate key = Key = Minimal Superkey?

I got a little confused by all these keys. As I understand A key of a relational schema = The minimal subset of a superkey that is still a key = A candidate key Is this correct or not?
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3answers
373 views

Many to many link tables with history? [closed]

While creating a PostgreSQL database of customer subscribed services with DNS domains, I want to: enable customers to subscribe to multiple services each service can have multiple domain names per ...
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1answer
162 views

message table schema - body TEXT or varchar [closed]

I want to make a small social network. For messaging body which one is more suitable? VARCHAR or TEXT? if VARCHAR how long is efficient?
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5answers
4k views

How can a group track database schema changes?

What version control methodologies help teams of people track database schema changes?
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1answer
94 views

How to reduce table duplication, while ensuring integrity of the database?

For example, in my app I have some class called Contact: case class Contact(name: String, email: String, phone: String) And several other classes have one-to-many relation to that contact (for ...
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0answers
333 views

Powershell to dump database schema to text file

I want to be able to dump a database schema to a sql text file using Powershell. I want this because our DBAs want to be able to do a diff on the file that is committed to SVN. They won't execute it ...
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5answers
1k views

Modifying table structure within a transaction?

In Oracle (and probably elsewhere), executing an ALTER TABLE statement will do an implicit commit on the current transaction. We have a tool (written in Java) that should modify a schema by: adding ...
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0answers
26 views

Create a schema like an existing schema [duplicate]

I have a existing schema in my database called SCOTT, how can I create a new schema with exactly the same privileges which SCOTT schema is having? Is there any create like or some command to create ...
0
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3answers
65 views

ER Schema “Optimisation”

I am trying to make an ER Schema for a person. The person will have Current Address and Permanent Address. So far I have it so that both Current and Permanent Address are Composite Attributes and they ...
2
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1answer
81 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 ...
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2answers
379 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 ...
2
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2answers
325 views

SQL Server 2008 R2 : A Possible indexing strategy for the given schema?

We have these four tables: Store ( row bigint, id uniqueidentifier, name varchar ) Products ( row bigint, id uniqueidentifier, storeID uniqueidentifier, productname ...
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109 views

Are duplicates ever acceptable in a database

A warehouse system I am working on allows inwards consignments [type = 0] and outwards consignments [type = 1]. The user selects multiple products for each consignment and then multiple warehouse ...
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1answer
776 views

Schema Change/Update script for Database deploy [closed]

I have a need to change the database schema . I'm planning to write Schema change and update scripts for tracking database changes and updating them. I followed Versioning Databases – Change Scripts ...
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1answer
119 views

Whether or not to create separate tables

I am working on a project, where I need to store the information related to A and B, the A and B both have identical columns.There might be thousands of As and Bs. Should I use "type" column to ...
0
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1answer
85 views

is there a recommended way to update many postgres schemes

I have a database in postgres which has 15 schemes, the schemes are identical with the same tables, views and functions. the system uses one scheme at a time, as if they were separate databases. So ...
0
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1answer
338 views

How does security context propagate between schemas within a database?

We have a SQL Server 2008 database that contains two schema's. The owners of these schema's have been granted full SELECT permissions to all tables within each others ownership. I have created a ...
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2answers
110 views

What is a standard or conventional name for a column representing display order? [closed]

For example, a junction table associating a product and its pictures: create table product_picture ( product_id bigint not null references product(id), picture_id bigint not null references ...
12
votes
3answers
29k 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? ...
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3answers
878 views

SQL Server 2008 R2 Express Edition - generating database create script

I need to script a database schema out to T-SQL for inclusion source control. The Express version of SSMS doesn't seem to let you script the entire database, just individual tables. Are there any free ...
2
votes
1answer
57 views

How to handle “or” possibilities in MongoDB

I'm new to MongoDB and by no means an expert in DB design in general. This feels like a really basic question that's probably been answered a million times, but I'm having a surprisingly hard time ...
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4answers
131 views

Is there a DB that will allow the same field name with different cases?

Is there a DB that will allow a user to create a table with two fields, one calls MYFIELD, the other called myfield?
0
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1answer
276 views

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 ...
4
votes
4answers
3k views

Open source tools for Oracle schema compares

I'm looking for an open source tool to generate DDL scripts. Many tools call these synchronization scripts. We essentially want to compare schema of different environments (ie: DEV to QA, QA to ...
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1answer
283 views

Database schema design help needed

I am developing a PHP application expecting millions of records both parent and children. My goal is to design an optimized database design to achieve high speed and performance. This application ...