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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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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2answers
695 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 message:...
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1answer
23 views

Count of range on datetime in MySql

I want to group table entries for each userId only if they are consecutive entries in the table. I have a table like this. id userId transactionTime 1 1 2016-04-13 22:15:44 2 1 ...
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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
46 views

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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1answer
32 views

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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67 views

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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0answers
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does insert “logs or traces” into RDBMS (example log4j) makes sense? What are pros and cons?

Our developers are inserting Java logs into a table. This table can grow very much (for example debug logging enabled) and I need to to truncate table. Our database is for OLTP. > desc ...
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37 views

Would it be good practice to represent MongoDB ObjectId as a String or a Blob type in SQL Lite (RDMS world)?

All: We have a software application with 1) Web-based component 2) Mobile-based component Our 1) Web-based component uses a) MongoDB as the Database b) ASP.NET C# Our 2) Mobile-based component ...
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79 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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27 views

Decompose the relation R into 3NF

I have a relation R(A,B,C,D,E) with set of functional dependencies A->BC, CD->E and B->D. My Method:- As we know Relation R is in 3NF if it satisfy below condition:- R is in 2NF There is no ...