Relational Database Management System, a widely used type of database management system characterised by its extensive use of joining as a core operational principle.
1
vote
1answer
34 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How does Postgres know which logs have been archived?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
votes
1answer
60 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 ...
4
votes
4answers
110 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 ...
16
votes
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 ...
0
votes
2answers
27 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
votes
0answers
55 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 ...
0
votes
2answers
90 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 ...
0
votes
2answers
46 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 ...
-2
votes
1answer
47 views
How to learn oracle business intelligence enterprise (OBIE) from scratch? [closed]
Hi I am a electronics and communication graduate but i want to learn Oracle Business Intelligence Enterprise(OBIE).I have some theoretical knowledge of RDBMS and SQL which i learnt during my ...
-1
votes
1answer
44 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!!!
28
votes
5answers
2k 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 ...
6
votes
1answer
735 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 ...
1
vote
1answer
165 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 ...
1
vote
2answers
225 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
vote
3answers
402 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 ...
1
vote
2answers
80 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 ...
4
votes
3answers
78 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 ...
1
vote
3answers
366 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
296 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 ...
26
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, ...
1
vote
1answer
237 views
Connecting to a SQL Server database from a Flash program
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 ...
4
votes
1answer
297 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 ...
0
votes
0answers
122 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 ...
3
votes
1answer
83 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 ...
1
vote
3answers
225 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 ...
5
votes
1answer
102 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.
...
1
vote
1answer
98 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 ...
2
votes
1answer
133 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
votes
1answer
214 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` ...
0
votes
1answer
90 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 ...
9
votes
1answer
449 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 ...
6
votes
2answers
198 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
votes
1answer
295 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 ...
10
votes
3answers
444 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 ...
1
vote
1answer
228 views
Which RDBMS best fits my need? [closed]
I realise this may be come a subjective mess, but I'm hoping for some objective information on the subject. I also don't want to go shopping, I just want to know 'what to shop for'.
I'm very new to ...
0
votes
0answers
91 views
recommend some good books on DATABASE MANAGEMENT SYSTEMS [closed]
Can anyone please recommend some good books on DATABASE MANAGEMENT SYSTEMS.
1
vote
1answer
67 views
Storing many small - and a few large - strings in an RDBMS
Let's say I have a table, and (among other things) it needs to store a large number of strings. Most will be small (20-100 characters), but a few will be quite large. Reads will be frequent, writes ...
3
votes
1answer
58 views
Why isn't there a way to label a column as “keyword”
In a typical star schema, you end up with a bunch of columns that are an ID into some lookup table, where the lookup table is pretty much just this:
create table hostnames (
id primary key,
...
1
vote
1answer
113 views
file not found - how to remove its configuration?
I run oracle 10.2.0.5.
I have the following:
SQL> select file#, status, error, recover, tablespace_name, name
2 from v$datafile_header
3 where recover='YES'
4 or (RECOVER IS NULL AND ...
2
votes
3answers
351 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:
...
8
votes
2answers
3k views
PostgreSQL vs. MySQL - Advantages / Disadvantages with a spatial component
We are the in the process of building out a web application that has a spatial data component. In the beginning our spatial data comparisons will take a given point and return matched overlapping ...
0
votes
1answer
300 views
which DBMS should i go for? [closed]
I am interested in learning a DBMS. As a beginner which DBMS should i go for ?
I know few DBMS by name like Oracle,Sql Server,My Sql . How are these DBMS different from each other ?
As a beginner ...
1
vote
1answer
155 views
Is there an Oracle rdbms monitoring API?
We have about a thousand customers with our application installed out of which 500 have an oracle database.
Monitoring the database is only one of the requirements.
Installing Oracle Enterprise ...
4
votes
1answer
118 views
how much overhead an error in RDBMS has?
I have a class in my project. On the class I need to do two inner select, to know is there any duplication or not, but I think if I get duplication error and then manage that is better than to select.
...
2
votes
6answers
530 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 ...
11
votes
2answers
558 views
NoSQL and RDBMS together?
I was wondering if there are any good solutions for recording data in a NoSQL database and then converting them over to an RDBMS?
For example, if you wanted to capture some data quickly, like ...
0
votes
4answers
3k 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... ...
5
votes
2answers
523 views
Single Drive vs Multiple Drives
Generally bottleneck of RDBMS (I am a MySQL user) performance is disk access. SSD provides great performance compared with conventional spindle drives.
Question : Is it possible to improve ...
1
vote
2answers
631 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?
11
votes
4answers
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?
