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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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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How to store external IDs from different sources?

I have a table of customers with a PK that we can use as an identifier for our internal system. These customers may belong to different companies, each of which may have an external ID in some ...
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Which foreign keys do I use if they are repeated

I have the following two tables company_relationships |ID|Company_ID|Affiliate_ID|<Relationship Info>| +--+----------+------------+-------------------+ jobs |ID|Company_ID|<Job Info>| ...
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Oracle dataguard - Redo apply

In a low bandwidth environment when a transaction commits that generates a large amount of redo data will cause other independent transactions to slow down. This is because the redo data of small ...
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637 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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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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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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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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Help writing the following query to relational algebra

Can someone help me in writing the following query to relational algebra, I am studying DBMS and I am stuck on this exercise. Query: SELECT a.name, d.name. d.grade FROM student a, enrolled i, class ...
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How to store highly configurable relationships based on multiple conditions

I'm trying to devise a schema that needs to be extremely configurable when necessary, but also minimal wherever possible. There is a large number of condition types that would lead to a number of ...
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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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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 ...