Relational Database Management System, a widely used type of database management system characterised by its extensive use of joining as a core operational principle.

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Setting up a new database [on hold]

I'm setting up a new basic database and wanted some on advice on the best approach to do this with. This would be a database in SQL Server 2012 and would be a reservation system for a customer. I have ...
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53 views

Running queries directly on DB2 databases

Just have a general query, if it is really fine or safe to run long select queries on RDBMS production Databases specifically DB2? If NO, what are the major risks and issues in executing select ...
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What is the advantage of using numeric primary keys in a relational database?

Many tables in a relational database system (in my admittedly limited experience) have this sort of structure (Oracle syntax as that's what I'm used to): create table widgets ( widget_id number ...
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30 views

Need some feedback on simple RDBMS design Project

Project: Create a simple group system for a social networking website. My Idea: Group table (ADDED_BY_MEMBER_ID = ADMIN ) Group Member table (I was thinking of added a IS_ADMIN column here ) ...
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113 views

Improve MySQL Query Performance - Too many records

I am using MySQL RDMS for a contact management system. Now a days my database grew in size and contains more than 1 million records. Checking duplicate phone numbers became a big issue during ...
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1answer
69 views

Optimizing indexes

I just began optimizing my schemas with indexes (pretty late I guess). I never dealt with huge dataset but I'll be soon coping with about 1 to 5 millions rows. Here is the schema I'm using right now ...
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1answer
118 views

MySQL: What is SQL mode and why we use it

If in an application, if we execute sql_mode=mysql4.0 as a first query in my application but using MySQL 5.1 in my application then what will happen? Will my system use MySQL 4.0 or MySQL 5.1 ...
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52 views

why should use MongoDB [closed]

In which types of projects, MongoDB is the best suited? Can we use MongoDB in large applications? Why Open Source CMS and framework doesn't have support for MongoDB? How it is different than other ...
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56 views

Why NOSql should be more performant than RDBMS under structured data loads?

The main reason NoSQL dbms have become so common is the need of storing unstructured data where a Relational database instead would require carefully designing a database schema and fitting data into ...
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45 views

WHAT RDBMS ( SQL SERVER/ ORACLE ) close to manage MYSQL(DBA) [closed]

i have a requirement for learning MYSQL for DBA. here all training institutes teach on ORACLE AND SQL SERVER. SQL is mandatory to work on RDBMS. what RDBMS SYNTAX CLOSE TO MYSQL for DBA(backups, ...
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71 views

MySQL: What criteria should I base my table column order/arrangement/grouping on?

Does the order, arrangement or grouping of columns with large (such as long text descriptions) and small (such as bit and tinyint) field types have any noticeable impact on MySQL (InnoDB engine) ...
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88 views

Type of Foreign Keys for a Dimensional Model Fact Table?

I've been reading about dimensional models, and in particular fact tables, but I haven't really seen one in action (i.e. the actual content), just diagrams of the table structures and column names ...
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1answer
147 views

Database Design Concept - Are Multiple Relationships A Bad Thing?

I have a question about Relational Database design. I'm just learning the basics of databases, so bare with me, in that I'm not sure of the technical terms for some of the concepts I'm trying to ...
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2answers
178 views

how to create an incremental database copy in postgresql?

Virtual machine software like VirtualBox allow one to make incremental VM clones. That is data, once "touched" (opened writable), will be copied and stored in the incremental cache of the new clone. ...
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1answer
420 views

Full text search through many tables in MySQL

We have high traffic NEWS websites, I want to add a feature that every user can search through over all content of site, such as news, polls, comments, galleries,etc . Each of contents type has its ...
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1answer
28 views

Plan for storing transactions in an easily retrievable manner, indefinitely

I've got a large (many columns) MySQL database table (InnoDB) that has a fairly high number of INSERTs (~500/day). Think of the records as financial transactions. Clients need to be able to view these ...
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90 views

Database design in MySQL

I am designing a database for an web application, in this system there are multiple users. Consider, Public (Buyer). Merchant. Tele Marketing Executive(TME). Marketing Executive(ME). Lead ...
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1answer
250 views

How does Postgres know which logs have been archived?

I'm asking this because Postgres was hard-stopped yesterday, and I fear that there could be partial / corrupt data in one of my archived log segments. I'd like to simply delete the logs from my slave ...
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102 views

SQL Server automatic transaction log truncation

Have looked through msdn but cant find answers to these: Any help much appreciated: In simple recovery mode: Is there any TSQL or alternative functionality that will provide a notification either ...
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4answers
333 views

In Memory Database for high transaction and volume spikes on a website [closed]

I am looking at the IA for a hypothetical application scenario, for example: A high demand application such as an online ticketing website where there can be demand for 100,000 tickets to be ...
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6answers
2k views

Why don't databases create their own indexes automatically?

I would have thought that databases would know enough about what they encounter often and be able to respond to the demands they're placed under that they could decide to add indexes to highly ...
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2answers
132 views

Partitioning MySQL for “expired” transactions to improve performance

I am dealing with an existing application that uses the database as a sort of transaction log in several cases, for example orders or payments. These tables are large (20 - 60 million rows) and poorly ...
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1answer
323 views

How to perform ETL from RDBMS to Neo4j

I have a mature 50+ tables web application based on mySQL. In order to do some advanced data mining I want to use Neo4j and the goodnes of cypher. However I'm having a hard time migrating my data from ...
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165 views

Storing data in PostgreSQL: One table or two?

I've just started using PostgreSQL 9.2 and my data consists of product prices at various points in time, usually a different price every month. Question: Because every product can have different ...
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64 views

Accessing Database without using SQL

This might be some ambiguous but I have not much info about this so I need some start point; As a general idea; in conventional RDBMS', there are a DB engine and storage of data. We use the language ...
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1answer
62 views

best database for a real estate system [closed]

Which is the best database suits for a real estate system. Considering the storage space, security, crash recoveries, speed etc. There will be around 1000 fields and trillions of rows!!!
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5answers
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Which database could handle storage of billions/trillions of records?

We are looking at developing a tool to capture and analyze netflow data, of which we gather tremendous amounts of. Each day we capture about ~1.4 billion flow records which would look like this in ...
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1answer
3k views

Using MongoDB and PostgreSQL together

My current project is essentially a run of the mill document management system. That said, there are some wrinkles (surprise, surprise). While some of the wrinkles are fairly specific to the ...
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1answer
273 views

join the two tables which possess one to many relationship

In drupal,the content type table and my own table is used to do some operations. Im having two tables namely Table1:'content_field_mem_id' & Table2:'Ex' description of ...
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2answers
1k views

A database in MySQL is a schema in Oracle : I do not understand this statement

Please help me understand this statement: A database in MySQL is a schema in Oracle. I have just started to use Oracle and I find it different from other RDBMS softwares I have used like MSSQL, ...
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3answers
3k views

Why is optimistic locking faster than pessimistic locking?

Both forms of locking cause a process to wait for a correct copy of the record if its currently in use by another process. With pessimistic locking, the lock mechanism comes from the DB itself (a ...
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2answers
130 views

How does optimistic locking actually enforce re-read/update?

My understanding of optimistic locking is that it uses a timestamp on each record in a table to determine the "version" of the record, so that when the record is access by multiple processes at the ...
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3answers
510 views

STARTUP command fails : Why is that?

I just installed Oracle Database Express Edition 11g Release 2.This is the first time I am using Oracle. Earlier I have used MySql and MSSql and I bet this one is a lot different ! These are the ...
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3answers
2k views

Detecting SQL Server Utilization with a query

My current project will send queries to an sql server constantly and It may use 100% of the memory or CPU. How can I check if the server is nearing full utilization in a stored procedure so that I ...
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MS Access trigger

I got a trigger to update a table in SQL. My actual need is in MS Access but I could not make it. So please help me to write the same trigger in MS Access. Query is as follows: Create trigger ...
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5answers
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Is it OK to keep a value which updates in a table?

We are developing a platform for prepaid cards, which basically holds data about cards and their balance, payments, etc. Up until now we had a Card entity which has a collection of Account entity, ...
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1answer
574 views

Connecting to a SQL Server database from a Flash program [closed]

I currently have the ability to utilize Microsoft SQL Server 2012. I am developing a project with Adobe Flash Builder 4.7. If I link my database with Adobe Flash Builder is there any additional ...
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1answer
462 views

Big Data vs Relational Database on making structure of Data-ware house for telecom data analysis [closed]

I'm currently doing my final year project on telecommunication mining. On starting project I got confuse on choosing database. As data on mobile communication is going on increasing so I think Big ...
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1answer
324 views

SQL Server 2008 R2 Database Diagram Error Code

I have sysadmin privileges on a SQL Server 2008 R2 server. I'm working with the development database and want to save a database diagram I created. When I try to save I get the following error ...
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1answer
127 views

Optimised Schema for City-to-City Distance Table

This is my first question, forgive me if this question is simple. I'm stuck here, trying to implement the relations for the data represented below. I want to scale it vertically (new rows), instead of ...
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3answers
352 views

Which RDBMS has the most advanced “table-valued” functions?

Every Database Management System focuses on specific features and applications. I am using mysql, probably as it is popular and satisfies common needs. However, I came across a problem, which needs ...
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181 views

Determining which isolation level is appropriate

This is a homework question. For the following transactions state the isolation level that will maximize throughput without lowering the integrity of the database. Explain the answer. ...
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1answer
135 views

Is there a major RDBMS that DOESN'T allow column name quoting/escaping?

The title basically says it: Are there any major DBs that don't handle column name quoting/escaping? For instance, suppose I want to have a column called FROM (and let's assume I have a really good ...
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1answer
263 views

Restriction on self referencing on insert in MYSQL?

How to restrict insert on adding self referencing rows in a recursive relation table (a table contains foreign key points itself). mysql> SELECT * FROM Employee; ...
3
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1answer
333 views

How to Update same table on deletion in MYSQL?

In my Database I have a table: Employee with recursive association, an employee can be boss of other employee. Following is query I used to create table: CREATE TABLE IF NOT EXISTS `Employee` ...
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1answer
114 views

How are transactions logs inserted?

I have an ms-access database at work that has a table that's a transaction log. The table contains the following fields: Date - The date the transaction took place. Table_Name - Name of the ...
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1answer
1k views

Commit vs Fast Commit vs Commit Cleanout in Oracle Database

I was wondering whether someone could verify my understanding regarding the differences between those 3 terms as pertaining to Oracle Databases. Many sources confuse these terms and do not explain ...
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2answers
347 views

How to modify an update in Oracle so it performs faster?

I have this query: UPDATE ( SELECT h.valid_through_dt, h.LAST_UPDATE_TMSTMP FROM ETL_FEE_SCH_TMP d, FEE_SCHEDULE_HISTORICAL h WHERE h.FUND_ID = d.FUND_ID AND ...
3
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1answer
367 views

Surrogate key / Primary key: Better to use an existing unique data field or create a key field?

I am not sure if this question has been asked or not. At least I couldn't find it. I am curious about a primary key in terms of efficiency with data searching and retrieval. This is a hypothetical ...
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3answers
832 views

Use MySQL to regularly do multi-way joins on 100+ GB tables?

Background: I’ve created a web application that I would like to be able to scale reasonably well. I know I'm not Google or Twitter, but my app uses a fairly large amount of data for each user and thus ...