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18
votes
1answer
681 views

What is the reasoning behind the CAP theorem?

http://en.wikipedia.org/wiki/CAP_theorem http://www.cs.berkeley.edu/~brewer/cs262b-2004/PODC-keynote.pdf I think it is not very straightforward why only two of Consistency Availability Partition ...
6
votes
1answer
753 views

Why can't we perform joins in a distributed database like Bigtable?

From this answer to What database does Google use?, BigTable is not a relational database. It does not support joins nor does it support rich SQL-like queries. Is this obvious? I do not ...
4
votes
2answers
1k views

Consistency in ACID and CAP theorem, are they the same?

From my understanding, the consistency in ACID is ensuring the data integrity. However, the consistency in CAP means the data can appear quickly in distributed system. Does that mean: they are not ...
3
votes
2answers
289 views

Database choices for big data

I have many text files, their total size is about 300GB ~ 400GB. They are all in this format key1 value_a key1 value_b key1 value_c key2 value_d key3 value_e .... each line is composed by a key and ...
3
votes
1answer
399 views

DB2 Express-C 10.1 database move to DB2 Work group Server/Enterprise Edition

I have not done such migration before and I want to know if I am going to face such issues when moving my database (tables,views,table-spaces,functions,procedures,etc.) to other DB2 distribution. If ...
3
votes
1answer
216 views

PostgreSQL synchronized commit performance

I'm setting up a pair of PostgreSQL servers. Because cash is short I can only afford one high class server and some crapy backup box. If the expensive high end box should catch fire, operations can ...
3
votes
1answer
156 views

Distribute MySQL in different cities?

We have our main MySQL server in city A. We have the bulk of our customer service staff in city B. The staff are complaining that the connection is too slow to the server. The options are: Have them ...
2
votes
1answer
31 views

Simultaneous money withdrawls from a distributed/replicated database

Lets say I have $10 in my bank account. The database is replicated in North America and Asia. At the exact same time I do a withdrawl of $10 in N. America and in Asia, meaning that my withdraw would ...
2
votes
1answer
201 views

Need scalable database solution for very big automated data entry database

I've been working on MySQL database in simple web applications for a long time and i now have a project which should maintain about 1,000 up to 10,000 query per minute (it is some logging database ...
2
votes
1answer
856 views

Does the pgpool-II extension allow for parallel execution of any query?

I read about pgpool-II here and it states that: Using the parallel query function, data can be divided among the multiple servers, so that a query can be executed on all the servers concurrently ...
2
votes
0answers
326 views

Upgrading Remote Distributor in SQL Server Replication

I'm upgrading my remote distributor from 2005 to 2008r2, it is performing transactional replication only. this is a prerequisite to completing an upgrade of the Publisher to 2008r2. Script ...
1
vote
2answers
4k views

Distributed Database Architecture Using MySQL Replication

I've been task to move our web servers to the cloud for all countries that use our services for localization. The issue is, they must share the same data and therefore I need to set up some database ...
1
vote
1answer
76 views

Designing a fragmentation database? [closed]

I did some research about distributed databases, but I still have some questions. I understand there is something called "fragmentation database" but I can't find any help full document for ...
1
vote
0answers
46 views

OrientDB distributed architecture

Technically this question could relate to any database that performs in a similar distribute manner but given that I am specifically working with OrientDB I thought the question should be target as ...
1
vote
0answers
11 views

Does the consistency part of the CAP theorem apply to updates and not first-time writes?

Using this definition of the CAP theorem: Consistency All database clients see the same data, even with concurrent updates. Availability All database clients are able to access some version ...
1
vote
1answer
629 views

What are alternatives to Replication to distibute data (Microsoft SQL Server)

Is anyone knowledgeable of alternatives to SQL Server replication? I have a scenario where separate databases will share a lot of the same data which complex queries will match against. We want to ...
1
vote
0answers
169 views

Distribute records on different MySQL databases - MySQL Proxy alternative

My scenario is the following: Right now I am using one big MySQL database with multiple tables to store user data. Many tables contain auto increment columns. I would like to split this into 2 or ...
1
vote
2answers
921 views

Difference between partitioning and fragmentation [closed]

I'm trying to learn something about distributed databases and I stumbled upon the concepts of fragmentation and partitioning. It seems to me as if both do the same thing and produce similar results ...
0
votes
1answer
47 views

Linked SQL Servers

I'm trying to link 2 SQL Servers (2008 and 2005). I have tried it via the GUI and scripts, and having no luck. I have problems trying to to query through it with access. As I'm not the Admin of the ...
0
votes
3answers
1k views

how to find vertica community edition and how to export / copy data

I have the hardest time downloading anything other than enterprise edition from vertica.com. It is supposed to have a community edition on https://my.vertica.com/community/ but all the links just show ...
0
votes
1answer
553 views

Model for Distributed Database [closed]

I want to design a model for a distributed database solution. Are there appropriate tools and approaches? How to include stereotypes for (horizontal) fragments?
0
votes
2answers
53 views

xml parameter to distributed query - difference between SQL2005 & SQL2012

I have inherited an old SQL2005 Enterprise database (on Windows 2003) that allows an xml parameter to a distributed query such as this: exec sp_executesql 'exec [server].[database].dbo.sproc ...
0
votes
2answers
895 views

Alternatives for Dblink in oracle?

we have an SSIS job that inserts data into a table in server A from data in table which is located in some other server B. For this,we are making use of dblinks to connect to other database . But, ...
0
votes
1answer
488 views

How to install and configure Postgres-XC in windows?

Can anybody suggest me any resources of the complete installation procedure of postgres-XC in windows. I've installed postgresql-9.2 in my windows and can use it. Now I need to know the installation ...
0
votes
1answer
131 views

Oracle DB - Is it possible to distribute data of a table onto multiple servers?

BigTable[1]-like systems (HBase[2] for instance) allows a table to be distributed transparently accross multiple servers. This works as follows: Each server perform the read/writes operations on ...
0
votes
0answers
17 views

In face of a network partition (P), does Neo4J HA allow read stale data?

In Neo4j docs it says that it is partition tolerant, but in further descriptions their docs does not make clear what happens if a network partition occurs. It enables a fault-tolerant database ...
0
votes
0answers
34 views

Is database sharding done on a table level or database level?

I'm new to sharding databases, so I'm trying to wrap my head around it. Let's say we have a database that has 3 tables: Customer, Suppliers and Orders. Each table has 10 million records. I want to ...
0
votes
0answers
32 views

Ascending and descending semi-joins

I was reading about semi-joins for a research paper implementation. i have to select the best way to reduce tables in a distributed environment for a particular query. for that it has 2 different ...
-1
votes
0answers
34 views

Database replica

I have a question about databases that I would appreciate if you can help me. Assume that a database server is up 10% of time. In order to achieve higher availability of this database in a distributed ...