Tagged Questions

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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2answers
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Import Oracle schema data without losing modifications of stored procedures

I have this scenario: One huge (thousands of tables), complex production database, Oracle 8 One huge (thousands of tables), complex development database, Oracle 9 ( same structure as production ) ...
0
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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
votes
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 ...
0
votes
2answers
365 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 ...
3
votes
2answers
691 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 ...
2
votes
2answers
323 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 ...
1
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0answers
108 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 ...
1
vote
1answer
740 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 ...
0
votes
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
votes
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
votes
1answer
336 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 ...
2
votes
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 ...
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 ...
-4
votes
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
votes
1answer
269 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 ...
2
votes
1answer
155 views

MySQL Performance Gains By Splitting Tables?

I am designing a database schema to be used with MySQL. The database needs to keep track of a users basket items and purchased items. I've thought about two ways I could do this but not sure which ...
1
vote
0answers
665 views

which role-permission database design?

I want to manage roles and permissions. Most of designs on web look like this tables: Users Roles UserRoles Permissions RolePermissions Here, what is permissions? I am thinking for such a design ...
0
votes
1answer
752 views

What's a good way to model user authorization to hierarchical data?

I'm wanting to implement something that's basically an ACL in SQL Server (2008, we'll be moving to 2012). We're working with farm production information. We will have users who need to be authorized ...
1
vote
1answer
461 views

Creating schema for a shop that sells items from multiple tables

I am trying to create a table in mySQl that contains a list of all the items that a shops. For example: shops (shop_ID (PK), shop_name) shops_and_items (shop_ID (PK), item_ID (PK), price) The issue ...
2
votes
3answers
237 views

Database design for conditional detail table

I have an expense management system for monthly expenses. Expenses are of two types: one-time monthly expenses, and daily expenses for each day of month. I have created the following tables: ...
1
vote
1answer
609 views

Oracle schema migration to new database with zero downtime

I have a problem: I have two production schemas on one database each serving two different appplicaitons. I need to migrate (move) one schema to an entirely new database that will be dedicated for ...
2
votes
1answer
106 views

Column type unknown at creation time

I have a table in a MySQL database that stores survey results. CREATE TABLE survey_responses ( response_id INTEGER UNSIGNED AUTO_INCREMENT, survey_id INTEGER UNSIGNED NOT NULL, question_id ...
2
votes
1answer
7k 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 ...
2
votes
1answer
55 views

Strategies for summary data in parent record based on detail data?

I have parent-child relationship as shown below. I need to find the first order date for each customer. Obviously, writing a query to do this is fairly straight-forward but it does require reading all ...
6
votes
4answers
569 views

How can a database be normalized when an optional field causes denormalization?

Suppose you have a warehouse full of widgets. Each widget in the warehouse is stored in a specific identifiable location within the warehouse. You might have a schema which looks like this: A ...
0
votes
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?
0
votes
1answer
94 views

When is it worth it to use Triggers and stored procedures/functions? [closed]

As an example, lets say I have a forum application and for every topic that is created, I have a trigger that fires a database function creating a post.(lets assume we have a topics table and a post ...
1
vote
1answer
135 views

Mysql: Schema/Query Performance Approach for aggregated mailbox folders

I am about to code a messaging system where users can write messages to other users. User can create custom inbox folders for sorting the messages they receive, however, every user has 2 main inboxes: ...
1
vote
1answer
185 views

What is the meaning of this anomaly warning message?

I have run an analysis with SchemaSpy. The tool gave me a warning message for two tables. The warning message is: Tables with incrementing column names, potentially indicating denormalization ...
5
votes
1answer
120 views

Many:Many with Shared Relation

I'm modelling data with multiplicity like this: Each Composition/Anthology related pair must share a Composer. Also, each Anthology must contain at least one Composition. How would you recommend I ...
0
votes
1answer
210 views

Postgres - Schema information within Trigger?

Background : (Multi-tenant design;separate schema per customer, all table structures identical;Data-warehouse / non-OLTP system here; Postgres 9.2.x). Reviewing patterns for the following problem: I ...
1
vote
1answer
2k views

Oracle database created whats next? Create Schema or Create Tablespace?

I'm a programmer that's being thrown to the DBA/Sysadmin island all by myself with a volleyball that I named Wilson. I'm trying to survive here. I'm supposed to create a database for an application. ...
0
votes
0answers
282 views

XML Data convert to SQL database,

I have an XML feed that i need to parse daily, i want to store all of the data from the XML feed in a SQL table so then that data can be queried and manipulated by my clients. I can currently parse ...
2
votes
2answers
215 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 ...
0
votes
0answers
80 views

In regards to GS1 barcode - what size DB field are used?

In regards to GS1 barcode - what size DB field is used or is the entire GS1 typically not stored in database, but rather processed in the application layer and stored in the database as a collection ...
0
votes
1answer
280 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 ...
25
votes
3answers
38k 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;
0
votes
2answers
1k views

Oracle schema import is not importing all the tables present in the schema dump file

I have exported an existing oracle schema from another machine and then imported it in my local machine. Import was successful, but some tables which are present in the export dump file are not ...
0
votes
1answer
41 views

Modify legacy table schemas that have no primary key

I've been tasked with updating our database (SQL Server 2008) so that every table in it has a proper primary key defined. Due to various reasons over the years we have somehow built up some legacy ...
1
vote
0answers
563 views

How to represent class table inheritance (current DBMS-specific way please)?

I want to implement class either-or table inheritance (Account, CatAccountDetails, DogAccountDetails) in SQL Server. I found a recommendation for MySQL here (How do I map an IS-A relationship into a ...
1
vote
1answer
730 views

Compare two MySQL dump files

I am trying to compare two MySQL dump files. One was made from a fresh install of a web application and the other is a dump from the same web application that has been upgraded from a previous version ...
4
votes
1answer
755 views

Will table inheritance in PostgreSql suit this situation?

Let's start off by saying, I'm new to PSQL and coming from a MSSQL background. I'm starting to design a DB in PSQL. So my main aim is to have a Main schema in this DB, which I am going to use to ...
12
votes
3answers
28k 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? ...
1
vote
1answer
46 views

Multiligual database design

I assume that the best approach for many languages (5 and more) is concept based on: CREATE TABLE `language` ( `language_id` char(2) NOT NULL, `collation` varchar(64) NOT NULL, ...
1
vote
2answers
234 views

Extensible Asset Database Schema

Background I work for a decent sized company in the hardware sector. Currently, we have a number of varying assets that need to be tracked. Until recently, this was done by hand as was an ...
0
votes
1answer
2k views

Granting permissions only on a set list of objects

I have a SQL Server 2005 database with a large number of tables in the dbo schema. I now created a new schema (call it myschema) that only has three table-valued functions and two stored procedures in ...
2
votes
2answers
65 views

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 ...
0
votes
2answers
2k views

MS Access ER diagram

I have database scheme for Microsoft Access. I'm interested how I can convert the scheme into an ER diagram? Is there any tool that can do this based on scheme relations?