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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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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1answer
201 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
369 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 ...
0
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1answer
349 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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1answer
79 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 ...
0
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2answers
121 views

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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0answers
36 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 ) ...
4
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3answers
618 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 ...
49
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6answers
15k views

What are the differences between NoSQL and a traditional RDBMS?

What are the differences between NoSQL and a traditional RDBMS? Over the last few months, NoSQL has been frequently mentioned in the technical news. What are its most significant features relative to ...
2
votes
2answers
209 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. ...
2
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1answer
75 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 ...
35
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5answers
6k views

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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5answers
2k views

Is ROLLBACK a fast operation?

Is it true that RDBMS systems are optimized for COMMIT operations? How much slower/faster are ROLLBACK operations and why?
0
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1answer
143 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 ...
0
votes
1answer
53 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 ...
1
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0answers
58 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 ...
8
votes
2answers
351 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 ...
1
vote
1answer
614 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 ...
2
votes
3answers
1k views

How does an OLAP cube database differ from an RDBMS?

Is a cube database, simply an RDBMS—such as PostgreSQL or MySQL—configured for OLAP via a star or snowflake schema? Or is a cube database different from an RDBMS, and if so how?
0
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1answer
49 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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0answers
75 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) ...
0
votes
1answer
112 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 ...
1
vote
1answer
155 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 ...
5
votes
1answer
497 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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vote
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 ...
0
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1answer
93 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
287 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 ...
0
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1answer
106 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 ...
18
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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 ...
4
votes
4answers
385 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 ...
2
votes
6answers
797 views

Is normalization process needed?

Well after learning DBMS as a subject i got so many questions in mind. Normalization is one of them. As i learnt it there was a lot more confusion and i found that whatever we do in normalization ...
0
votes
2answers
148 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 ...
0
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2answers
176 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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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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2answers
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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votes
1answer
63 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!!!
2
votes
3answers
606 views

Which database is best for deeply embedded database or through C DLL?

I want a deeply embedded database. Deeply embedded means that the server is started by an application and closed by the application with no tcp/ip or 0 port. The main features of consideration are: ...
5
votes
4answers
2k views

Why are so many MPP solutions based on PostgreSQL instead of MySQL?

Astor Data, Greenplum and GridSQL all allow Massive Parallel Processing of SQL queries. They are also all built around PostgreSQL technology. Is this just because of licensing issues or are there ...
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1answer
283 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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vote
3answers
374 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 ...
3
votes
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, ...
1
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2answers
133 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 ...
2
votes
3answers
3k 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 ...
0
votes
0answers
1k views

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 ...
27
votes
5answers
2k views

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, ...
0
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4answers
6k views

What's a good client tool to access Oracle RDBMS? [closed]

I'm looking for a good client tool to replace "Oracle SQL Developer" (the tool I currently use) which supports: Oracle DB 10g, 10gR2, 11g Running SQL code Debugging SQL code (with walk-through... ...
4
votes
1answer
478 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 ...
3
votes
1answer
130 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 ...
5
votes
1answer
204 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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vote
1answer
142 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 ...