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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Duplicate Relationships in Rails/MySQL Healthcare Application

Overview of the Application I am building a Ruby on Rails application to organize medications, using MySQL. The goal of this application is to provide dosage specific treatment recommendations, and ...
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Apply operation on all schemas

I have an Oracle instance, with several schemas (all starting with the same prefix). PATT_A PATT_B PATT_C ... All of them have the same table, and I'd like to update all of them in one shot (with ...
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SQL Server vs Oracle [closed]

I am transitioning from SQL Server DBA to Oracle DBA. I have minimal experience with Oracle, and I have found that the best way for me to traverse if by correlating terminology and database engine ...
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789 views

How to normalize my db schema for a quiz application?

I am putting together a quiz application. (I'm calling each quiz a "challenge") I have a "challenge" table and a "challenge_question" table which is pretty straightforward. challenge table: id ...
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1answer
79 views

Understanding of schema and tablespaces - recommendation for a later seperation [closed]

DLDR: I would like to get a confirmation of my understanding of tablespaces and schemas (see image) a recommendation how to organize schemas and tablespace to make a later separation easy. ...
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816 views

MySQL DB structure with Main category and several nested sub categories

I am looking to create a set of fields on my webpage identical to what eBay uses on their category selection page when you are selling something. For my purposes I am doing motorcycles, power sports, ...
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282 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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494 views

Designing Simple Schema for Disaggregation of Demand Forecast

I am doing a simple database design task as a training exercise where I have to come up with a basic schema design for the following case: I have a parent-child hierarchy of products (example, Raw ...
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72 views

Divide a PostgreSQL database into schemas

My Postgres database will be focused on multidisciplinary organizations. The project axis is: a person could belongs to diverses disciplines (ex: arts, sports) for the same organization, and this ...
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55 views

What schema for different relation from two tables to another?

There are three tables instructors, meeting_points and bookings. Here are the relation I want: 1 instructor has 0, 1 or n meeting_points 1 booking has 1 meeting_point 1 meeting_point can be linked ...
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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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116 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 ...
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Is there a tool to check if my database is normalized to the third normal form?

I learned about normalization recently, and understand how important it is when implementing a new schema. How can I check if my database is 2NF or 3NF compliant ? Manual review is a sure option, ...
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281 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 have migrated 2005 server data with modified data schema to 2008 R2 from yesterday's date of data. My ...
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2answers
1k 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 ...
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1answer
50 views

Database templates [duplicate]

Are there any site with database templates for specific purposes? (i.e. a database schema for users and authentication in a webpage) for different databases like Oracle, MySQL... I have been looking ...
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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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2answers
194 views

MySQL JOIN two tables and get latest result

I want to JOIN two tables and get the latest result from each one of those two in a single table. I'm kind of concerned about speed too since tables are growing kinda fast. Close to 60-70k records a ...
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44 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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66 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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Query table with the same name on different schemas in PostgreSQL [duplicate]

I want to query table with the same name (for instances "walls") in multiple schemas on a PostgreSQL database. Is it possible? I am searching for something like this: select * from *.walls; I need ...
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1answer
59 views

Database design: handling time

I am developing a weekly timetable which ideally would allow teachers pick what subjects they teach. While most of this is fairly straightforward, from a conceptual point of view I am unsure how to ...
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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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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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55 views

PizzaShop - DB - Normalized Schema

I am trying to make a simple DB in Access for a theoretical pizza shop(the db is for an assignment). What I am trying to do is link one type of pizza to one or more types of toppings. I just wanted a ...
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29 views

Generate Schema Only Script from SQL Server 2012 to SQL Server 2008R2

Hi this is the first time that I've encounter this error in generating script for my database, what do you think causes this error? Thanks. Please see image.
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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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671 views

how to avoid duplicated column in two different tables?

OK, I'm inexperienced in terms of database design, so hopefully my question isn't too silly. I have 2 tables users and user_profiles these two tables has one-to-one relation between them. ...
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57 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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1answer
324 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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40 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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3answers
71 views

Postgres: modify existing search_path (preserve current values)

Sometimes I would like to extend the existing search path, rather than replace it, say: To start with say it is already set like so: SET search_path TO schema_b, schema_c, public; I want to add my ...
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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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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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219 views

Which is the better schema design for a voting system?

Imagine a q/a site or forum similar to stackoverflow. I'm trying to determine which of these two methods would be the better design for a voting system: (note: I would also like to keep record of all ...
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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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Are there any tools to go from ERD to DB design and vice versa? [closed]

I'm learning DB design and looking for some tools, preferably open source software, that could help go from an ERD to a DATABASE and vice versa. For the record, the database i'm using is MySQL.
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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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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
45 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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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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1answer
2k views

DB2 - how to safely blow away database on linux?

I'm using (I believe) 10.1.2, on CentOS 6.5 (for sure). The underlying problem I have is that the database upgrade package prepared in house isn't working for me, in at least the sense that the ...
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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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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 ...
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2k views

How recording of every change of a row in a database is generaly stored?

In a project I'm working on, every change to the rows in some tables of the database must be tracked for further audit or rollback. It must be easy to find who modified the row, from which IP address ...
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1answer
98 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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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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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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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 ...