Can I do without Entity-Attribute-Value?

You need to do something similar to an online store. The problem is in choosing the method of storing information about the goods, as there are more than a hundred types of goods and each of them has its own set of attributes. The same Magento Commerce for these purposes uses the EAV structure, due to which select requests become very complicated and do not work very quickly. So far, the only thought is to periodically convert EAV into a normal table, from which samples will be drawn. Is ther... Read more

Sharding MongoDB under load?

How does a MongoDB shading behave under load? Especially how does Map / Reduce affect the system load? Read more

NoSQL - application features

When is the use of such databases as MongoDB, CouchDB, Redis and some others justified? Does it make sense to put them instead of the classic mysql, on a site with a weak load? Are they used in conjunction with mysql, or work separately? Read more

Replication Redis

I am engaged in one startup in which we use radishes, now the question of building a fault-tolerant database cluster has come close. As is known, radish currently supports only master-slave replication. It is necessary that if a master falls, one of the slaves would take the function of a master. For this purpose, I found the following solution: When the master crashes, this monitor selects a new master and sends a synchronization signal with it to t... Read more

How to extract N random non-repeating elements from SET in Redis?

There is a SET c 1000 id, you need to choose 3 random and non-repeating. The decision "in the forehead" - make SRANDMEMBER 3 times, but there is no guarantee that there will be no repetitions. You can - control replays at the client level and cycle the SRANDMEMBER cycle until the received set is unique, but this is also somewhat clumsy. Sort by random value (something in the spirit of SORT ... BY RAND LIMIT 3 INTO ...) Redis does not know how. As a result, SORT ... INTO ... the result... Read more

Should I use Mongo?

Greetings! Recently, I hear more and more mentions about NoSQL and MongoDB in particular. I was interested in the topic, but I still can’t find the information that interests me, so I’ll ask here - probably many have already managed to experiment and maybe develop serious high-loaded applications in conjunction with MongoDB. I will warn you in advance if somewhere I made a mistake regarding MongoDB - I did not specifically. I just didn’t even try to work with her, but just read the article... Read more

Opensource ScalaxyDB Database

Hello! Is there a ++ developer who would like to join the opensource project of a non-relational self-balancing p2p database ScalaxyDB? Sources: Google Group: Read more

File storage: MySQL, NoSql or something else?

Hello. I think over the system and get up the following tasks. Necessary: ​​ 1. Store about a million html files 2. As many text files 3. zip, pdf files 4. Requires a search for text and html files. If it matters, then I have some experience using the mysql + sphinx bundle. Scalability is needed up to about 10 million html and as many text files. What solutions can you advise? 1. Where and how best to store html and txt files? 2. Where and how best to store archives and ... Read more

Chat for PHP: database bottleneck - how to solve?

There is a task to organize a simple chat with a web interface and a complete history on a working site on a samopisny engine (PHP5.3.3 / MySQL5.1). Googling on existing solutions didn’t give anything good, either redundantly or produces a feeling of “kneeling crafts” and most often hasn’t been supported for a long time, and I would like to have one architecture and coding style. In general, it was decided to implement independently. There are no special problems with coding, the prototype was i... Read more

Advise the database (pure Java, Schema less, embedded, in memory)

Please advise: pure Java, Schema less, embedded, in memory the database. To use as a cache with the ability to search by object properties. Well, or other options how to organize such a cache :) Thank! Read more

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