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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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 ...
43
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3answers
67k 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;
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43 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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1answer
171 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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3answers
57 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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3answers
1k views

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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1answer
35 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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1answer
35 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
38 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) ...
2
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1answer
46 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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1answer
1k 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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2answers
56 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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2answers
1k 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 ...
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3answers
1k 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
60 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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0answers
20 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 ...
2
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0answers
46 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"? ...
2
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1answer
47 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
222 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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4answers
74 views

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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0answers
16 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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6answers
11k 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 ...
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1answer
389 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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2answers
169 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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0answers
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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0answers
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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10 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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152 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
212 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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2answers
693 views

noSQL ACID and consistency for banking

We are building a real time banking platform and app. Our prime concern is safety and consistency of our data across multiple db servers. We need transactions and we can't afford to risk power ...
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0answers
35 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 ...
2
votes
1answer
92 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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1answer
203 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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3answers
1k 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 ...
0
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0answers
34 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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1answer
441 views

Should I save “document ID” as a String or Number in MongoDB

So I'm importing about a 100,000 documents into mondoDB. MongoDB already generates an Object hash but the data has a documentID that was used to identify records in the previous database. The IDs ...
0
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2answers
38 views

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 ...
2
votes
1answer
404 views

Is there any way MySQL can list relationship cardinality between two entities?

I am working on the project where I have to analyse the MySQL schema. As a part of schema information, I want to list down relationship cardinality between different relations. Does MySQL stores ...
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0answers
12 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 ...
0
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1answer
110 views

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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0answers
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 ...
4
votes
2answers
810 views

Backup Only Database Schema Everynight

I have an instance with 15 databases on SQL Server 2012. I will set up to backup system which will work every night. I want to backup only the schema because several databases are very big. I haven't ...
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0answers
50 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 ...
0
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1answer
143 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 ...
4
votes
3answers
4k views

database schema design for school system

I am trying to create a database to store information about a school. I need to store each department in the school. Each department then has a list of teachers. Each teacher has a list of classes ...
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0answers
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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1answer
100 views

Convert multiple databases into schemas SQL Server

Due to a high amount of databases being created on my project and the rising cost per databases I had the following question: Is there a way to convert multiple databases in SQL Server into one ...
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1answer
300 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 ...