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20
votes
1answer
783 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 ...
8
votes
2answers
4k 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 ...
7
votes
1answer
920 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
59 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 ...
3
votes
2answers
329 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
471 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
252 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
0answers
441 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 ...
3
votes
1answer
163 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
55 views

Postgres data integration

Consider a scenario where I have 3 standalone running Postgres engines that are installed on three separate machines. The data on this machine is inserted, updated or removed each month by employees. ...
2
votes
1answer
276 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
992 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
3answers
1k 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
2answers
6k 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
618 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?
1
vote
1answer
102 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
2answers
106 views

MYSQL find if a default value has been set for a table (DateTime Specifically)

I am trying to internationalize a database, but there are places where the timestamp that gets set is using NOW() instead of UTC_TIMESTAMP(), and it's using Amazon's RDS with multiple MySQL servers. ...
1
vote
0answers
31 views

Distributing MS Access Database

I develop an application that saves records in MS Access DB. Each user has it own DB copy on his local machine, and there is a central DB that reflects all the copies from everyone. The central DB is ...
1
vote
0answers
21 views

Implementing a unique primary key for distributed databases

I've got an issue to find a way to create a global primary key to a given relation (namely "Patient") In a distributed database there are three local sub-systems: surgery department, emergency ...
1
vote
0answers
214 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
20 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
284 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
2k 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
57 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
2k 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
2answers
263 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
2k 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
570 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
287 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
9 views

Designing Users table on DistributedDB

I am using SQL Server 2012 SP2 Express with PDB Wrapper 1.0.4 on 7x Partition nodes + Common server. Currently my users table is shared on common but we see high network latency. We left users table ...
0
votes
1answer
33 views

Machine learning database Big data

Which databases can I use for storing object features for machine learning use case, in case of Big data? To explain a bit more - object features basically represent an object in a form of an array ...