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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SQL Broadband Market Dilemma [closed]

edit -- Hi I see this post has been closed. Not sure what that means, but I'm guessing I wont be getting an answer. Any idea on where I can go on the internet to get an answer. I've been on-line for ...
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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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Does MariaDB support schema changes inside a transaction?

MySQL doesn't support schema changes, inside a transaction so there's no way to roll back after during a failed migration involving schema changes. This capability is supported by Postgres and ...
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27 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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33 views

Error 42P01: relation does not exist

I'm new at creating databases, and this error has me dumbfounded, as I am super new with DB admin things (I mostly do reporting type queries). I created a new database through pgAdmin3 GUI, and I'm ...
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27 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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35 views

How could I improve my DB design?

I'm a second year software engineering major looking to create an iOS app that connects to a MySQL database (database not yet created) over the summer. I have a strong understanding of programming and ...
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29 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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53 views

Schema Design with “Seasonal” Data

I am developing a SaaS web application for School Management. What I need help is this: The whole application is purposed for the current year that the School is in. However, some data and ...
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28 views

How can I limit a user to only be able to run procs in a schema, which access another db?

In a SQL Server 2012 SP2 Standard Edition instance I have a user in database A that needs to be able to run stored procedures in schema foo within that database. They shouldn't be able to do anything ...
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25 views

Normilsation - 2NF and 3NF

I've been through several questions and youtube tutorials, i understand that 2NF is removing the partial dependencies and 3NF is the transitive ones, but i can't get my head around how the following ...
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1answer
32 views

How can I create a mongo db based on mysql squema?

How can I create a mongo db based on mysql squema? this is my schema productCode VARCHAR(15) productName VARCHAR(70) productLine VARCHAR(50) productScale VARCHAR(10) productVendor VARCHAR(50) ...
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29 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 ...
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45 views

Schema to make a Payment History/Viewing History

On some websites I have seen two history of events: Payment History and View/Watched History. I want to have both payment and viewing histories in my app, but I got stuck when I started thinking ...
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1answer
42 views

db schema for a object with multiple foreign key tables

I have a question table which contains question_id, question_text and choice_type_id ( say freetext, binary choice and multiple choices ) Now, the question table (which has question_id, ...
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18 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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41 views

Tuple Relational Calculus help? [closed]

I have the following three questions in relation to the following diagram: 1) How many copies of the book titled “The Lost Tribe” are owned by the library branch whose name is "Sharpstown"? ...
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1answer
44 views

Why wouldn't I put the single preferred option into its own table, instead of having a 'Preferred' column?

In similar spirit to How to implement a 'default' flag that can only be set on a single row I would like to specify that, for any given list of possible names for a business, only one of the ...
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1answer
149 views

Is an ER diagram an example of a conceptual, logical or physical schema?

I have been reading databases, and I clearly understand the difference between a conceptual, logical and physical schema. An ER diagram is an example of which of these schema's?
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How can I compare the schema of two databases?

Is there a way to find the differences in two SQL Server databases (schema only). One is local and the second is at a customers site. We are experiencing problems with crystal reports running some ...
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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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1answer
147 views

Pros and cons of using many schemas in PostgreSQL as opposed to just one?

For a large SAAS application (backed by PostgreSql 9.4), with over 300,000 accounts (and growing), what are the pros and cons of using a schema per account to partition the data vs putting all the ...
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160 views

Is EAV an appropriate design for a collection of coexisting metadata-rich “fact estimates” on objects? [closed]

I'm attempting to architect a system that will collect estimates on various quantities (10+) on each of many (300K+) objects, and make decisions from the historical record of these estimates. For ...
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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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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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1answer
189 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 ...
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105 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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1answer
137 views

Use a set database schema or EAV design? [duplicate]

I have already created a database design with a set schema. The database schema is for a web quotation form. PS it is not a simple quotation form and hence need to customise the form, form builders ...
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31 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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1answer
68 views

How to efficiently create a new PRIMARY KEY CLUSTERED definition online

Given a table with a PRIMARY KEY definition (acting as the clustered index), I want to efficiently change the definition of the PRIMARY KEY (or at a minimum, just the clustered index) online. I would ...
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2answers
25 views

Can we determine FDs if we are given some tuples?

I am taking a databases course and i'm learning about functional dependencies. I have searched around and did not find any information on this. My questions is if we are given a table with some ...
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23 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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159 views

Is there a best practice for recurring calendar events

I'm not a dba but a php programmer, so that I'm not an SQL pro. Now, I have searched in both programmers and dba stackexchange sites but the answers are too specific or not conclusive. My question is ...
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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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Is it a good idea to add a reserved field to a large MySQL table?

As you may know adding a new column to a MySQL table with millions of records is hard and in some cases impossible. Is it a good idea to add a text column to each table (say, meta) to save some ...
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Dropped connections, corrupted schema … is MySQL sick?

Lot's of problems and I wonder if it's all tracable to some root cause. I'm trying to load a simple schema related to product marketing. The symptoms are: Not being able to forward engineer said ...
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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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47 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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1answer
102 views

How does Amazon create the RDS for Postgres? Some kind of Docker?

I am really curious about the infrastructure of Amazon. When I create a new instance of RDS, it gives me a host, username, password.. Everything. Behind the curtains, how do they do this? It´s some ...
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29 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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166 views

Not able to solve issue: Incorrect string value: '\xC5\xABt\xC4\x97'

I am facing database error Incorrect string value: '\xC5\xABt\xC4\x97'. I did a lot search and tries a few ways, include move from utf8 to utf8mb4. But still not able to solve it. Following are the ...
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217 views

Insert rows in a table, via a row-level trigger, activated after insertion in that same table

I have to design a schema and trigger system in SQL that will save words and their synonyms. I thought of this basic schema: create table words ( id int primary key auto_increment, word ...
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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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1answer
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In Oracle, how to get a list with the names of schemas that a user has read permission?

In Oracle, i need list which schemas a particular database user (or the current database user) has read permission. Based on this information, also need to get all the tables and views are in each ...
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1answer
91 views

Schemas and user permissions

When our custom, home-grown CMS creates data tables using the GUI, it creates them against the site-specific user schema (i.e. sitename) instead of the dbo schema. The issue is that our ...
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30 views

Design for periodic data cuts

I've been building an application that has a 6-monthly update schedule, i.e. a cut of the data for H1 & H2 of each year. The previous version of this application implemented this by making a copy ...
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42 views

Need Help in building database

I am developing an app that send messages (email and sms) to users. The db must also maintains the list of messages send to users. And also the status of messages send to user like send or failed. I ...
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185 views

Migrating everything to do with a schema from one Oracle DB server to another

We have an old DB server, running Oracle 11g on Solaris. We also have a new DB server, also running Oracle 11g, but on RHEL. We want to move a schema to the new db - but we need everything it refers ...
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Schema copy from 9.5 V to 10.5

Using DB2 move utility db2move to copy schema and database from source to target server. The source server is Server1. The target server is Server2. Do I need to set up the TCP/IP port ...