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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Possible SQLite bug?

I am running into an issue with SQLite that I think might be a bug. When I run the PRAGMA table_info command on a view that uses an aggregate function, the data type always comes up empty. To ...
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320 views

Oracle sqldeveloper Database Diff - not seeing indexes/sequences

I am using Oracle SQL Developer's database diff tool to compare schemas. (SQL developer version : 3.2.09) It works great on some environments, but in one, I can only see differences in tables - the ...
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45 views

Improving performance of a weighted search query in SQLite3

For an intra-site search I have this table in an SQLite3 database, that relates ids to search terms with a certain weight: CREATE TABLE search_index ( id INTEGER(7) REFERENCES other_table, ...
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65 views

Schema for user drag and drop ordering

I'm trying to work out the schema for a system where users will be able to order items in an (unlimited length) list by drag and drop. Is there any kind of standard way of storing this ordering ...
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66 views

Proper design of routes in Database MySQL

I'am trying to find out the best database design and try to stick with data integrity by using Foreign Keys. But I'm stuck right at the beginning because of limit relations between tables with FK to ...
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893 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 ...
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26 views

Allow user select from table in another user's schema that has policies set

I have an oracle10g database with 2 users - user A and user B. I want to select data from a table in user A's schema from user B. I have granted user B select privileges on the table in question but ...
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21 views

Alter schema of Access 2013 database with linked table

I'm trying to change the schema of an Access 2013 table. I want to lengthen some of the text fields. When I change the schema and try to save I get dialog with Operation is not supported for this type ...
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21 views

How to differentiate between class and attribute

I have this problem: Library has books, VDOs, CDs Journals. It gives loan to users. Books and Journals can be referential which cannot be loaned out more than 2hrs and non-referential which can be ...
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11 views

CLR UDT SCH-M blocking

I’m hoping someone can provide some guidance on a problem I’m having with schema locking on C# CLR UDT’s. I’ve been on the Internet for an extended period of time researching my problem without ...
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42 views

Mongodb schema design validation

I am building an app which allows users to do some "tasks" to earn points. The "tasks" are part of a "campaign" which themselves are a part of "brands". I am confused about the schema for storing the ...
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39 views

In terms of relational databases is a Relvar the equivalent to a Schema?

I've been reading up on relational databases and the term Relvar and schema keeps coming up. From my understanding: A relvar is a variable holding a relation. A schema is a logical definition of a ...
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31 views

To implement a facade DB table or not? [pics]

Does it make sense to normalize a schema with tables that only serve the purpose of logically separating parts of a system? Below are 2 example schema with what I am talking about. (sorry about the ...
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80 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 ...
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315 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 ...
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124 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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402 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 ...
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121 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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101 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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121 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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714 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 ...
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536 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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31 views

Where to put the currency field?

Abbreviated I have following tables: Companies own flats and rent them for specific periods_in_time and lastly a currencies table. The price column is sitting in the periods_in_time table. But where ...
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24 views

Multiple table relationship for different scenarios!

We have the following heirarchy in our platform; Package is comprised of Products, Products is comprised of Services and Services are comprised of SKUs. The relationship between them is many-to-many ...
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55 views

DB schema for an invoice system with tiered prices

I've been hired by a payment gateway company that handles payments for its customers. Every month, a script is run and will charge each merchant for the bulk number of payments completed. The unit ...
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36 views

pt-online-schema-change with statement based replication in MYSQL

Is it possible/safe to use pt-online-schema-change in a Master slave environment where as the way replication is setup is statement based(SBR). What is the better way of doing it as currently I have ...
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57 views

Referral table structure

I need to make a simple referral system and I have a database table set out as follows: mem_id | date | refer_email | accepted And the meaning of such columns is the following: mem_id: The ...
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12 views

When to use tags vs binary fields in a constituent management system?

I have a table of Constituents and I want to track yes or no qualities like: are they a teacher? are they an elected official? are they philanthropists? There will be less than a dozen of these ...
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47 views

SQL Server 2008 R2 Error Msg 15063 and Msg 15410

I just execute a Schema Script from my SQL Server 2012 Database to SQL Server 2008 R2. I'm using same SQLAdmin account for this two Server. But when I execute the Schema Script I receive an error ...
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58 views

The module <''> depends on the missing object <''>

I'm executing a Schema Script from a new server, and I get an error saying The module <''> depends on the missing object <''>. My question is, does it affect my database? or what is the effect ...
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38 views

Is doing an online alter on a MySQL table to add comments safe?

Is doing an online alter on a massive MySQL table to add or edit table or column 'comments' safe? Or do you need to take precautions like you would while adding, removing columns, etc on that table?
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19 views

Database Design for Resume and Sections

I am trying to figure out if I am on the right track here. resumes id user_id resume_sections id name desc Sections are those that we normally find in resumes, experience, skills, education and ...
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19 views

Schemas with the same name in a Redshift cluster?

Is it harmful in some way to have multiple schemas with the same name in a database cluster, specifically Redshift? I want to create multiple databases, and then create a schema "tables" or "data" or ...
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8 views

How to handle private local databases in a multiDB cloud environment

In context of Platform as a Service (PaaS), we would like to offer our clients a private platform. A platform includes a website and a database. A platform is not 100% separated. Users could "travel" ...
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196 views

Railway Reservation System [Miniature] Schema

I am working on designing a schema to support the development of a miniature railway reservation system, using oracle 11g XE. This is for a project purpose, I am need to be sure about the correctness ...
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49 views

The MondoDB.org “Category Hierarchy” Example

I am creating an MVP app for a client but I am skilled in iOS mainly with only some DB experience. I'm using MongoDB. The schema is for a Product Catalog for small markets. The client wants a ...
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14 views

database structure for an object of keywords

Each object I am storing is made up of a title, a description and 10-20 keywords. Each keyword is grouped and some groups can only have one member keyword assigned to an object. Objects will only ...
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19 views

How to model role and different activities

I am new in the database design and I'm facing this problem, I hope somebody can help me. In my domain we have 3 roles, Non-Supervisor, Supervisor, Manager. I created a Person table and a role table ...
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55 views

what is better, multiple column or multiple rows while schema design

I would like to know, which is best in fast retrieval and reporting as numbers of records will increase with time. So lower the record better would be the performance. Priority would be fast response ...
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32 views

Percona and MariaDB-10.0 ignoring not null on table fields

On the percona-5.6 and MariaDB-10.0 servers, the NOT NULL declared on table field are being ignored. I am able to leave fields declared as NOT NULL empty when inserting data and the servers are not ...
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185 views

LCK_M_SCH_M Blocking

I have 2 stored procedures (one vendor, one third party) that are constantly (monthly) stepping on each other. They both (for some reason) acquire a schema lock when all they are doing is updating ...
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37 views

Accounting - Dimention table in mysql

I am designing a accounting and mini erp system. I use a date dimension table to track all date related data. In oracle we can have many schema for a database. so we could create each schema for ...
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53 views

How to determine a schema version at runtime

Is there a portable way or best practice to access a version number for a schema at runtime? Rationale: you have multiple systems (development, QA, etc.) where you push schema changes from one system ...
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69 views

Entity Schema Design

I'm working on an application that has an "entities" system (built before my time) that models users, customers, contractors, vendors, etc. These are all types of people, but have different needs in ...
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26 views

How to store highly configurable relationships based on multiple conditions

I'm trying to devise a schema that needs to be extremely configurable when necessary, but also minimal wherever possible. There is a large number of condition types that would lead to a number of ...
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30 views

Database & Structure for SaaS reporting software

I'm building a SaaS application to allow users to upload data and perform reporting and analytics on it. The reporting and analytics would be quite simple like grouping and aggregating. This has ...
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173 views

Changing Schema ownership and side effects

I am trying to understand why changing schema ownership is causing permissions to be revoked. I am having a hard time understanding schema ownership change. Here are the steps I have taken in ...
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0answers
187 views

Export sql server table connections schema

i am using RazorSQL to connect to a Microsoft SQL Server database. I am looking for a way to visualize the tables connections schema. Do you have any idea how I can export such a view?
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49 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 ...
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318 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 ...