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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6answers
6k 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 ...
2
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1answer
111 views

To normalize or not to normalizde? (10 fields)

I'm helping someone to design a database and for a specific case I'm not sure. I have 10 fields - this will never change - that will always be filled and used in every query that could be coming up. ...
2
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1answer
82 views

Relational modeled design to store versioned files

The scenario I have images in a database table and some of these need to be altered then re-saved(not overwriting the original) whilst providing a reference back to the original. I also save the ...
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3answers
770 views

MySQL schema for recurring events - Query by specific date

I've just asked this exact same question on stackoverflow so apologies for cross posting but I only just noticed dba so thought I'd ask across here as well. I'm just about to start putting together a ...
0
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2answers
492 views

Multi-Tenant (SaaS) Database Schema with Sharing

Guys I just need your opinion which is the best approach to design a schema of a database for a SaaS application. I want it all on a single database, At first I think I can simply put a context_id ...
3
votes
1answer
92 views

Help with “Flexible” vs Fixed Tables

We are designing a database in SQL Server to handle sales commissions. A diagram of the current schema looks like this: There are only a couple of us on the project, and our boss dropped this ...
0
votes
1answer
108 views

one to zero or one relation strategy

For a 1 - > 0..1 relationship (Let's say a product can have none or 1 product_price) What are the differences between this 2 scenarios. When one should be encoraged over the other or is anyone bad ...
2
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1answer
91 views

Saving passport information [closed]

For starters: Our company is based in Germany and thus is based on German law. Germany now has adopted a new act regarding anti-money laundering and which information needs to be stored. Now we're ...
0
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1answer
129 views

understanding (and modelling) grocery shopping lists

I am having a hard time understanding how multiple product orders are mapped out. What is the best way of modelling a shopping list for multiple customers? I am developing an C# application that ...
2
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2answers
843 views

Postgresql: Query across schemas

I have multiple schemas that I need to query across. The schemas are not know in advance for example: U111 U222 U333 I need to select across these three schemas from a specific table in each of ...
3
votes
2answers
5k 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?
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0answers
60 views

Do supertables produce bottlenecks?

There are several alternatives to using polymorphic associations and one of them is to use the so-called "concrete supertable". From my point of view, this is the neatest solution and is pretty easy ...
2
votes
2answers
300 views

Dynamically change schema to accommodate custom fields!

I am working on building a sort of a cms for a particular project. Nothing that will have a large volume of records in any table. Within 6 digits max. I was thinking to create the default schema for ...
0
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0answers
32 views

Multi language where this feature never existed

I need to implement multi language system in an existing system that was not developed for this. The number of entries in the tables that will hold data that has to be translated will not exceed 5 ...
0
votes
1answer
117 views

Help With MySQL Computed Columns/Auto Updating Field Based On Average

I am currently building a social network type application on-top of MySQL and have run into a problem I can't wrap my head around. In my web application each user has a field called "weight" and this ...
0
votes
0answers
178 views

Review a database schema for a design approval system

I'm working on my first web application that will utilize a database. The basis for the application is a design approval system. I work for a company which mainly produces print and online marketing ...
0
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0answers
99 views

Mysql profiler different duration information_schema.profiling

Hi! I have a problem and no idea how to resolve it. I'm trying to use mysql profiler. I'm using the command: set profiling=1; to turn it on. Later, i execute my query which is correlated ...
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2answers
3k views

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 ...
0
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0answers
43 views

Unique database presentation ideas

I have completed the first phase of a fairly large database schema design. I built the ER-diagram in DIA. I have to present the schema to an audience of fellow software engineers. Any thoughts on ...
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0answers
79 views

Lossy Decomposition meaning

Suppose I have a relation R=(A,B,C,D) and I decompose it into: R1=(A,B,C) R2=(A,D) then if it is said that the decomposition is lossy,then what is the meaning of that statement?I have an ...
1
vote
1answer
174 views

Can I alter a view being referenced with schemabinding if the change fulfills the binding requirement?

In SQL Server 2008, I have views WITH SCHEMABINDING and I need to alter one. I am changing a column while not changing its alias so consumers will be unaffected. If I were to drop all my other views ...
0
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0answers
41 views

How should I restructure a table that contains multiple columns that contain similar, but not same data?

I currently inherited an InnoDB table that describes a product. In the table there are a few columns that describe the maximum height at which the product may be mounted. These are the columns: ...
3
votes
1answer
1k views

Drop auto increment hack w/o alter table?

I was looking around for a quick way to remove an auto increment from the definition of a primary key. As best I can tell the only way to do it is w/ an alter table or dumping all the data into a new ...
10
votes
4answers
1k views

eCommerce orders table. Save prices, or use an audit/history table?

Im designing my first eCommerce schema. I've been reading around the subject for a little while, and am a bit confused about the relationship between an order_line_item and a product A product can ...
3
votes
2answers
220 views

Is there a well-known name for this “poor man's ref. integrity” schema design pattern?

Is there a name for the following database schema design/pattern? My eventual goal is to find more literature about the subject. Today's cursory net search was too full of generic words to be able pin ...
1
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1answer
134 views

Scheme review/Normalization level/query optimization

So I have a relatively complex database I'm designing - basically full in-house accounting setup. In one section I have some concern that I'm over-normalizing; the 'directory' - I'll example the ...
1
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0answers
51 views

MySQL Workbench Forward Engineer from only the current diagram

I want to create a test database from a huge schema in MySQL, but when I try to do Forward Engineer from a Diagram with about 6 tables, it try to create all the tables, views and routines groups that ...
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0answers
307 views

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 ...
3
votes
2answers
53 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. ...
0
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0answers
45 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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0answers
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". ...
22
votes
3answers
34k views

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;
7
votes
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 ...
0
votes
1answer
190 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 ...
0
votes
1answer
257 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 ...
1
vote
1answer
73 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, ...
0
votes
2answers
65 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 ...
0
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0answers
44 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 ...
2
votes
3answers
276 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 ...
1
vote
0answers
71 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 ...
5
votes
2answers
615 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
vote
1answer
226 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 ...
4
votes
1answer
557 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 ...
0
votes
2answers
97 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. ...
1
vote
2answers
298 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 ...
1
vote
2answers
161 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, ...
1
vote
1answer
235 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 ...
1
vote
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 ...
0
votes
1answer
284 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 ...
1
vote
2answers
195 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 ...