What is the easiest relational database to understand?

Question

Database

Which of the relational databases seems to you the simplest, most understandable and logical. Well, except for sqllite. Exclusively in terms of the availability of convenient tools and logical management. Speed ​​doesn't matter.
A big request - at least somehow explain your opinion with examples in comparison with other databases.

Answer 1

There are not so many more or less common relational databases now:
Oracle DB and Microsoft SQL Server are definitely not suitable for "simple". These are big enterprise solutions that people spend a lot of time learning.
SQLite - You asked not to write (although the definition of "simple, logical and understandable" fits perfectly: there are no users and some other complicating functionality, while maintaining the SQL standard quite well)
MySQL is the most popular database, with a huge number of examples, tips and etc. Moreover, in all languages ​​of the world.
By itself, this database is not a model of consistency and simplicity, but if you come across it every day for several years, then it "suddenly" becomes more understandable than the rest.
PostgreSQL is logical and pleasant in itself, but far from simple. There is a lot of functionality, and a lot of complex.
There is a good "comparison" (rather a description of the general differences) of SQLite MySQL and PostgreSQL.
About the less common ones:
It's not very clear what is needed at all. The question is very abstract. If you need not only simple, understandable and logical, but also to understand it, then you need to have at least some material (answers to questions, examples, tutorials).
Here is the page of the Russian wiki (there are not only relational ones in the list, I skipped them)
Let's look at those who have at least a page in the Russian wiki. (If there is not even a page, then it is unlikely that this database will be advised to anyone on a Russian-language resource). I apologize in advance for running through the tops (I didn’t work with most of the database, I could make inaccuracies):
* Caché - "positioned by the manufacturer as "object-relational" or "post-relational"" - hardly "simple and understandable"
* DB2 and Informix - bases data about which I could not even understand whether they are simple or not. Both are IBM products. Maybe she is one of them - what you need (I really did not figure it out).
* Ingres - Predecessor of PostgreSQL (I don't see the point in dealing with it when Postgre is there)
* mSQL - no longer being developed, was superseded by MySQL
* Btrieve - no longer being developed
* LINTER - not being developed anymore
* Adaptive Server Enterprise - not free (to be honest, I'm too lazy to look further)
* Microsoft Access - comments are superfluous
* OpenOffice Base - I think it's the same as Access - suitable for office managers
* Rdb - the predecessor of Interbase, you can put horseradish on a PC
* Interbase - the predecessor of Firebird
* Firebird - by the way, a fairly well-known database, it may well compete with MySQL, etc. After studying additional information about it, maybe I would even advise it as not so complicated, like Postgre, but not a departure from the standards and MySQL mess (although I didn’t work with Firebird myself, maybe it’s even more complicated and confusing there)
* HSQLDB - looks like a small, lightweight database that supports SQL standards well and that's it. That is, it quite fits the definition of simple, but close enough to the previously rejected SQLite for some reason.
As a result, I will write the prevailing general subjective opinion:
Light and (therefore) simple - SQLite (easier to work with the database, more information), HSQLDB (works according to SQL standards ).
Lots of information, lots of features, logical - PostgreSQL.
A LOT of information, quite simple, not logical in many ways - MySQL.
Quite simple, relatively little information, quite logical (generally average everywhere) - Firebird.
PS While researching the Internet, I completely forgot about the fact that the question was about the availability of convenient tools. On this point
MySQL gets 5
PostgreSQL - 4
SQLLite - 4
Firebird - 4
HSQLDB - 3