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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DB2 (LUW) equivalent for Oracle “drop user cascade”

This question is related to creating and initialising test and development databases for an application that has the database running on LUW (linux-unix-windows) On oracle, we have an os user (on ...
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2answers
145 views

Does this medical database look correct?

I'm pretty new to databases and I'm trying to create some schemas. I've been working away at this one for a while, but I can't help feeling that it doesn't look right. Essentially I have the ...
0
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1answer
995 views

Postgres 9.3 changes the standard_conforming_strings value

I'm migrating a legacy application's database from Postgres 8.1 to Postgres 9.3 In order to avoid compatibility issues, I'd like to keep the standard_conforming_strings parameter to it's default ...
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2answers
44 views

Design for table with multiple links to other table

I am designing a database to keep track of our network equipment. My db has 2 tables: sites & circuits (circuit = cable) & (site = property location) Each circuit runs between two sites, so ...
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0answers
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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1answer
140 views

Data modeling with many attributes where few apply to each record [closed]

I'm pretty new to data modeling, so please excuse me if I've missed something obvious. I'm trying to decide on a schema (or possibly a DBMS) to work with some data where there are quite a few possible ...
2
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2answers
68 views

Is there a good way to select a row where the key represents the lower bound of a range?

I am designing some tables and a number of the tables have as the key a lower and upper bound which never overlap. I want to query by a value that can fall withing any of those ranges. If I keep both ...
0
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2answers
68 views

Transfer all tables from a schema to other schema

I have two schema. Schema1 and Schema2 How would I transfer all the tables from schema1 to schema2?
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1answer
256 views

Do I need to explicitly grant permissions for a login under the sysadmin role for it to access a custom schema?

So I have a login that has sysadmin rights on the db server. However, it's not able to access database objects under a custom schema that was created (eg. it cannot select from tables with ...
6
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1answer
53k views

How to transfer data using expdp and impdp commands?

I'm Oracle noob, and my intention is to transfer all data and metadata from one schema to another schema within an Oracle database. I'm planning to use datapump expdp and impdp commands. I have ...
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2answers
67 views

query multiple unrelated tables

Just learning mysql and db so guess this is a general schema design question. Say i have 10 different types of widgets and each widget transaction has a date, amount and 8 other unique columns to that ...
2
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1answer
1k views

SQL Server many-to-many relationship, row reuse?

Below is your typical many-to-many relationship. Pretend there are 2 tasks that have the exact same Tags. because of foreign key/primary key relationship constraints, there is no way for the rows in ...
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1answer
204 views

What will GRANT <privilege> ON ALL TABLES IN SCHEMA <scheme> TO <role> do?

It seems obvious that PostgreSQL will GRANT some privileges ON ALL TABLES IN some schema TO some role when I'll command. But, will it make it permanent for the schema that on all tables within it, ...
5
votes
2answers
471 views

Searching 500 million records of binary data

I will inserting into a database the signatures of 500,000,000 pictures. The signatures will be generated using libpuzzle. Each signature is 338 bytes. (so 160 GB) plus a table for searching (read ...
2
votes
0answers
224 views

How do you think in NoSQL? [closed]

I'm from the pre-nosql era and am rather comfortable with SQL. However, I cringe whenever someone suggests using a NoSQL database for the "upcoming" project. There are some major problems that I'm ...
0
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1answer
42 views

Delete all types created by a user

In Oracle 10g, how do I delete all the types owned by a specific user? This is the view that gives me the types I want to drop:SELECT type_name FROM user_types;
2
votes
1answer
102 views

Review database schema / thought process

Please review my thoughts below. It is written in an authoritative style because it is the most succinct, not because I am competent. Please poke as many holes as possible. I am trying to create a ...
0
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1answer
132 views

Need some expert eyes to look at my schema

I am trying to make an online site for local movies. Will be written in PHP and will be using MySQL as the database. What I want is to create a mini IMDB type site, with movies, people(casts/crew), ...
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2answers
195 views

MySQL 5.5 to 5.6 Upgrade. Will data remain the same?

We are considering to upgrade to MySQL 5.6 this summer. I would like to know if our data will be changed in any way once we perform the upgrade? I've been reading and I found that mysql_upgrade ...
2
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0answers
175 views

Database Design - Multiple Dbs or Single - Security & Data [closed]

I've hit a brick wall with this and just cannot make a decision so want to throw this out there and see if there are any issues I have'n't considered. Basic Topography I have a system that currently ...
0
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1answer
580 views

Split MySql table into two tables with One to many Relationship

I have an old database table in MySql. It is used to store the orders from online ecommerce. Simplified diagram looks like this: +----+------+-----------------------+-------+--------------+ | id | ...
0
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1answer
79 views

Unable to check is schema is present first

I've created a SQL script that will release a process to numerous SQL Server instances so I want to check if a paticular schema is present before creating the schema. I'm using the below and it ...
1
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1answer
122 views

mongodb Date strings and other issues

I asked a question on Stackoverflow, and was told that my schema was way off. I am using mongodb to store whether or not a log file exists. The log file contains info for an hour. I'm not actually ...
1
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1answer
839 views

Oracle schema migration to new database with zero downtime

I have a problem: I have two production schemas on one database each serving two different appplicaitons. I need to migrate (move) one schema to an entirely new database that will be dedicated for ...
2
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1answer
480 views

Database deployment script for SQL Server 2008 has different behaviors

Using Visual Studio 2008, I have compared schemas between remote SQL Server database with scripts hosted in a TFS server. The goal was to generate a migration script that would update the remote ...
0
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1answer
406 views

How can I Automate MongoDB schema design from existing MySQL Database and Logs?

I am working on the project which will automatically generate sample MongoDB schema analyzing existing MySQL database and logs. I am looking for help regarding the below questions. Please, share your ...
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1answer
2k views

Script not allowed to create schema objects when generating tables despite db_owner role

I am looking to make a "schema only" (no data) copy of a database on my local server. I used Tasks -> Generate scripts to script the tables from my existing database and then after creating the new ...
0
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1answer
52 views

Create menu from multiple meals relationship

I have the following relations: Meals(meal_id, name, cuisine, ingredient) Users(user_id, name, username, password, email) Chefs(chef_id, name, username, password, email) I want to create the ...
0
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1answer
366 views

Airport Database Design guidance required

I am trying to make a generic database for airport management and DBMS would be oracle 11g xe. Since, i am amateur and still learning so i have tried to kept the problem statement simple with limited ...
5
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4answers
3k views

Are there any free online collaboration database schema tools? [closed]

I am interested in a free and simple MySQL tool which can offer online collaboration functionality in creating database general schema. Do you know any?
2
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1answer
125 views

To normalize or not to normalizde? (10 fields)

I'm helping someone to design a database and for a specific case I'm not sure. I have 10 fields - this will never change - that will always be filled and used in every query that could be coming up. ...
2
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1answer
97 views

Relational modeled design to store versioned files

The scenario I have images in a database table and some of these need to be altered then re-saved(not overwriting the original) whilst providing a reference back to the original. I also save the ...
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3answers
2k views

MySQL schema for recurring events - Query by specific date

I've just asked this exact same question on stackoverflow so apologies for cross posting but I only just noticed dba so thought I'd ask across here as well. I'm just about to start putting together a ...
0
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2answers
927 views

Multi-Tenant (SaaS) Database Schema with Sharing

Guys I just need your opinion which is the best approach to design a schema of a database for a SaaS application. I want it all on a single database, At first I think I can simply put a context_id ...
3
votes
1answer
169 views

Help with “Flexible” vs Fixed Tables

We are designing a database in SQL Server to handle sales commissions. A diagram of the current schema looks like this: There are only a couple of us on the project, and our boss dropped this ...
0
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1answer
429 views

one to zero or one relation strategy

For a 1 - > 0..1 relationship (Let's say a product can have none or 1 product_price) What are the differences between this 2 scenarios. When one should be encoraged over the other or is anyone bad ...
2
votes
1answer
121 views

Saving passport information [closed]

For starters: Our company is based in Germany and thus is based on German law. Germany now has adopted a new act regarding anti-money laundering and which information needs to be stored. Now we're ...
0
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1answer
280 views

understanding (and modelling) grocery shopping lists

I am having a hard time understanding how multiple product orders are mapped out. What is the best way of modelling a shopping list for multiple customers? I am developing an C# application that ...
4
votes
2answers
6k views

In Oracle how do you move a Schema to a different Tablespace?

I noticed that a Schema has been created in the USERS Tablespace but our local rule is that it should be in a Tablespace by itself. In Oracle how do you move a Schema to a different Tablespace?
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0answers
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 ...
2
votes
2answers
1k views

Dynamically change schema to accommodate custom fields!

I am working on building a sort of a cms for a particular project. Nothing that will have a large volume of records in any table. Within 6 digits max. I was thinking to create the default schema for ...
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0answers
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 ...
0
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1answer
157 views

Help With MySQL Computed Columns/Auto Updating Field Based On Average

I am currently building a social network type application on-top of MySQL and have run into a problem I can't wrap my head around. In my web application each user has a field called "weight" and this ...
0
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0answers
315 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 ...
1
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0answers
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 ...
1
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1answer
467 views

Can I alter a view being referenced with schemabinding if the change fulfills the binding requirement?

In SQL Server 2008, I have views WITH SCHEMABINDING and I need to alter one. I am changing a column while not changing its alias so consumers will be unaffected. If I were to drop all my other views ...
0
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0answers
70 views

How should I restructure a table that contains multiple columns that contain similar, but not same data?

I currently inherited an InnoDB table that describes a product. In the table there are a few columns that describe the maximum height at which the product may be mounted. These are the columns: ...
4
votes
1answer
2k views

Drop auto increment hack w/o alter table?

I was looking around for a quick way to remove an auto increment from the definition of a primary key. As best I can tell the only way to do it is w/ an alter table or dumping all the data into a new ...
10
votes
4answers
2k views

eCommerce orders table. Save prices, or use an audit/history table?

Im designing my first eCommerce schema. I've been reading around the subject for a little while, and am a bit confused about the relationship between an order_line_item and a product A product can ...
3
votes
2answers
248 views

Is there a well-known name for this “poor man's ref. integrity” schema design pattern?

Is there a name for the following database schema design/pattern? My eventual goal is to find more literature about the subject. Today's cursory net search was too full of generic words to be able pin ...