Is there a distinct winner among all the key-value stores? Cassandra, MongoDB, CouchDB? and do they all follow some central guidelines? or they all have their own say in defining their APIs. I'm asking this question, especially from a perspective of a RDBMS skilled person who is new to key-value stores. Which one should we follow to bes...
When would one choose a key-value data store over a relational DB? What considerations go into deciding one or the other? When is mix of both the best route? Please provide examples if you can. ...
I can see myself using Project Voldermort to cache results from a Traditional RDBMS query. But in this case, it provides almost no major advantage over other (Java) caching system such as EHcache Jcache etc. Where else could I use Project Voldermort or similar Key Value stores ? How are you using this in your business applications ? ...
I'm trying to wrap my head around Key-Value stores like CouchDB and Cassandra. I understand why they're useful but as far as how they replace a RDBMS like MySql, I don't get it. Let's say this is my what I need to store: {123456: {'model' : 'Ford' 'color': 'blue' 'MPG': 23}} Then I need to find all the cars that a...
What is a clean/efficient method for storing the directory Hierarchy/tree in a Key-Value database (in my case MongoDB but any of them). For example a tree structure - Cars + Audi + BMW - M5 + Ford - Color + Red - Apple - Cherry + Purple - Funny The method I am using now, each object links to it's p...
I'm trying to populate a ComboBox programatically. I am creating ComboBoxItems and would like to set their text (the text that is visible for the end-user) and their value (the object that I will handle in the background after the user has selected it. However the ComboBoxItem seems to only have one member for these two requirements: th...
I need a fast, reliable and memory-efficient key--value database for Linux. My keys are about 128 bytes, and the maximum value size can be 128K or 256K. The database subsystem shouldn't use more than about 1 MB of RAM. The total database size is 20G (!), but only a small random fraction of the data is accessed at a time. If necessary, I ...
An extra requirement is that the attachments can be stored as a stream, as there might be potentially very large binaries that has to be saved. Videos etc. I have looked at Voldemort and other key value stores, but they all seem to expect byte arrays, which is completely out of the question. This should, preferrably, be written in Java...
I'm writing a recursive function to construct a multidimensional array. Basically, the problem is as follows: function build($term){ $children = array(); foreach ( $term->children() as $child ) { $children[] = build($child); } if(!count($children)){ return $term->text(); } else { return $...
I am looking for nosql key value stores that also provide for storing/maintaining relationships between stored entities. I know Google App Engine's datastore allows for owned and unowned relationships between entities. Does any of the popular nosql store's provide something similar? Even though most of them are schema less, are there m...
I am being required to use a postgreSQL database and it will replace my current use of berkeleyDB. Although; I realize this is not an ideal situation, it is beyond my control. So the question is... If you were required to make postgreSQL into a key value store how would you go about doing this, while making it as efficient as possible?...
Hi, Is there a key value store that will give me the following: Allow me to simply add and remove nodes and will redstribute the data automatically Allow me to remove nodes and still have 2 extra data nodes to provide redundancy Allow me to store text or images up to 1GB in size Can store small size data up to 100TB of data Fast (so w...
I'm looking for a key/value store meeting the following requirements: Open Source C API (C++ okay too) ACID Some level of crash recovery High [storage] capacity per file Both key and value are arbitrary binary data Embedded (like DBM, SQLite, et al.) GDBM looks particularly attractive. Per the fact that the datum struct uses int ds...
I am finding some difficulty in accessing mutable dictionary keys and values in Objective-C. Suppose I have this: NSMutableDictionary *xyz=[[NSMutableDictionary alloc] init]; I can set keys and values. Now, I just want to access each key and value, but I don't know the number of keys set. In PHP it is very easy, something as follows...
Hi, I am planning to build a web app running on a single computer and exploit the hardware resources as efficient as possible. The logic of app will not be complex. The following is my design: OS: Linux (CentOS 5) Web Server: Nginx Web script: PHP Database: Tokyo cabinet + Tokyo Tyrant Index: Sphinx I am not going to use RDBMS such...
I have used many SQL abstraction libraries, such as ODBC, JDBC, and ActiveRecord. What are the abstraction options in the NoSQL / key-value store world? I am mostly asking this so that if I choose a key-value store then I can use an abstraction library and not be locked in, which I think is important given the number of key value store...
How can I implement a large relational database schema on a key value store? The following are the requirements: 1) uses no stored procedures or special database vendor specific features 2) Uses indexes 3) Uses joins 4) Many complex types in tables (VARCHAR, INT, BLOB, etc) 5) Billions of records 6) Full text search 7) Timestampe...
What is the easiest way to simulate a database table with an index in a key value store? The key value store has NO ranged queries and NO ordered keys. The things I want to simulate (in order of priority): Create tables Add columns Create indexes Query based on primary key Query based on arbitrary columns ...
There are a multitude of key-value stores available. Currently you need to choose one and stick with it. I believe an independent open API, not made by a key-value store vendor would make switching between stores much easier. Therefore I'm building a datastore abstraction layer (like ODBC but focused on simpler key value stores) so that...
By maps I mean lists of unique key-value pairs. Is there a language-independent recommended architecture? ...