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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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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3answers
105 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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1answer
103 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
63 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
66 views

How can I create a MongoDB based on MySQL schema?

How can I create a MongoDB based on MySQL schema? This is my schema: productCode VARCHAR(15) productName VARCHAR(70) productLine VARCHAR(50) productScale VARCHAR(10) productVendor VARCHAR(50) ...
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1answer
226 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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2answers
217 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
215 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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23 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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76 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
51 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
795 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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1answer
423 views

Database Schema for Resume/CV and Separate 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
1k 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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2answers
212 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
26 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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1answer
1k 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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743 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
798 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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55 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 ...
3
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1answer
393 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
29 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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2answers
582 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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2answers
46 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 ...
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1answer
245 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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23 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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1answer
11k views

SQL Server: grant select access to a user in a view and not in its tables

I have a SQL Server 2012 instance with a few databases. In one of them I created a view, that selects tables in more than a database. I want a user to be able to select that view, but it must not ...
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0answers
69 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
416 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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0answers
37 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
445 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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1answer
828 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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76 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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2answers
1k views

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
178 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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1answer
61 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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1answer
49 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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1answer
793 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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1answer
69 views

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 ...
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0answers
112 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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0answers
636 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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0answers
41 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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1answer
105 views

ALTER TABLE blocking in MySQL 5.6

I have a question with a MySQL 5.6 master-slave setup. If I were to modify the master's schema with an ALTER TABLE SQL query, then when the slave tries to execute that ALTER TABLE statement too, would ...
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1answer
467 views

PostgeSQL 9.3: What is the difference between text and pg_catalog.text?

I have a classic 3-environments setting (dev, staging and production), each with its own RDS PostgreSQL 9.3. The client/server versions are psql (9.3.5, server 9.3.3). In order to keep the schemas ...
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2answers
350 views

Is there a way to replicate certain part of collection in Mongodb

Is there away to stream certain part of collection in MongoDB or TokuMX from master server to another server? I need to duplicate only certain collection Or if it isn't possible, are there any other ...
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1answer
167 views

can I give permission to insert into view, but not to referred table?

Here I have a view in public schema referring to the table in private schema: CREATE OR REPLACE VIEW public.products AS SELECT products.id, products.product_id, products.title, products.company_id ...
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1answer
449 views

MySQL table indexes change location [closed]

Is it possible to move the MySQL Table indexes to another location rather than "datadir" ? for example a ssd drive or memory partition ?
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2answers
49 views

Schema/Structure to handle secondary computed data

I'm trying to design a LAMP-based website for my pinball league, which plays competitive pinball every week in match play. One of the features of our league is that we convert raw scores to ...
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2answers
74 views

Can I update only the needed changes in a database?

First of all, I apologize if you can't understand very well what I am saying and it can be edit for better understanding of my post. The next example is for better understanding of databases with ...