Internal implementation of database queries

Question

In my experience, I used a lot of queries like select , order , where , etc. in mysql, sql-server, oracle, etc. For a moment I thought

1) as it is written internally to implement the above requests

2) what language do they use?

3) is a programming language? if so, which language?

4) what environment is required to implement such a complex database

Answer 1

1) In a schematic form, you should act as follows:

a) ​​ (AST) . , lex yacc , .

b) , , , , , , ...

c) , . , " " AST

d) node

2-3) , . C, Java .

4) , - .; -)

SQL/, , , .

Answer 2

, Oracle C , , .

Answer 3

MySQL C, ++ MySQL Launchpad

, , MySQL .

Postgresql.

Answer 4

(?) /. , . RDBMSes, , . .

, SQL Server

PostgreSQL MySQL