Scenarios where a relational database cannot be used

Scenarios where relational databases cannot be used-reproduced:

10 cases where the relational database is not available: things never to do with a relational db | Application Development-infoworld may be able to play a role in the direction of ordinary people.

Translation of the main effect is as follows:
1. Search: Even if the Oralce store does not use Oracle Text on its own, you will see many people using complex like query statements, which are very ugly, compatibility is quite poor,

The process of getting data from an Oracle database is difficult, except for Oralce, where there is virtually no real search extension.

It is recommended to use similar hibernate Search, Apache SOLR, or even Autonomy. can have better performance.

2. Recommendation: This is the ugliest place for many e-commerce products, they get a lot of data about the user and then try to recommend it.

Consider a social network scenario, if your friend buys socks, I also recommend socks to you, this is the data obtained from the RDBMS, we will use SQL statements such as join table multi-level query,

This requires only two lines in the gallery such as neo4j. You can use a relational database in a social system, but you will lose your natural real-time nature.

3. High-frequency trading: Most of us believe that a trading system must be an RDBMS because it guarantees transactional performance, right? Wrong. High-frequency traders tend to be the first people to use NoSQL,

For HFT low latency for the king (Low latency means fast response, especially for large traffic situations to quickly complete user transactions), of course, you can make high-difficulty basketball shots,

You can also use a relational database to do low latency, but the relational database is not really designed for this purpose. Oracle tried to negate the above conclusion by buying TimesTen, trying to combine a memory-based database with an RDBMS,

But you will penny wise lose watermelon, we see HFT most use Key-value storage, tears such as Riak, even more complex such as GemFire.

Scenarios where a relational database cannot be used