Introduction to MongoDB


Hello everyone, I want to mentionabout MongoDB which is one document database of NoSQL databases. This post includes what MongoDB is, terminology of MongoDb, Replication and Sharding mechanism and useful information/notes. Hope you enjoy! If you see any wrong or incomplete information, please leave a comment to update it together. I prepared this post such as brief of MongoDb documentation.

I honestly recommend to join MongoDB University according to your development type to learn more deeply with examples and community. There is a weekly program.

What is MongoDB?

MongoDB is an open-source document database. I mentioned about CAP theorem in my NoSQL post. In this theorem, MongoDB is between Consistency and Partition Tolerance but it compromises for Availability. What MongoDB offers us?Read More »


What is Time-Series Data?

In this post, I want to mention about time series and its databases. Why do we need them? Where can we use? I also add some papers, videos and references to get more detail of them.

Time-series is simple meaning of where time is x axis and data(serie) is y axis in graph. So, we have continuous data and it depends on “Time”. We got until this point. Where can we use these series and need its databases? If your data are stored with time and they are going to be huge(big), you can use them. We can also store them in relational databases as SQL. You are right but just tell a real story. You are twitter and each second a billion tweet is already post and all of them includes at least one hashtag. At the end of day, someone ask how many tweet is post for “this” specific hashtag? (You need something more than traditional databases.) This website ask to twitter API to show stats (warn: you can spend a time! -> keyhole)

Okay, another example, you are ceo of chain market such as Ikea (Välkommen till min blogg – ahah), and you want to see how many customer entered your stores by country for last one month (this is irony, I couldn’t found any best effort database to support month, because you never know how many days in a month. – 30? 31? 28? 29?) Anyway, so you have counter device in all entrances and these devices connect each store and each stores connect to center servers. You need a really good system to handle this throughput. You are a designer, you can use any database or tools to collect these data (even assembly can be solution on network). But you do not have time to discover America again. I love this sentence…

Read More »

Not Only – SQL

Hello, everyone! I start my blog with most common trend No-SQL databases. Some of you heard about what it is, but I want to mention about more detail information without boring you. I put my references in the end of post.

Everybody knows relational databases such as MSSQL, Oracle, MySql etc. If we think opposite term, there is also no-SQLs which are not relational databases (That does not mean we do not need relational databases!). Why we need no-sqls? Recently, technology is changed and data is mass by day by. And we need to process these data and get some ideas from them. There are real-time applications (IoT) and really huge amount of data should be stored. At that point, these databases help you to store these data and process faster. But, we cannot use same syntax and language as we use in traditional SQL, because the systems are different.

So, what is advantages and disadvantages if we compare with traditional databases.


Read More »