What should a SQL developer know?

Question

SQL

Hello. I have ~2 years of experience as a SQL(PL/SQL) developer. Now I am actively digging towards PostgreSQL, fortunately, in many respects it is similar to Oracle. So I'm wondering what a SQL developer should know with the prospect of entering Administration and ETL (Data Warehouse, etc.). At the moment I work as a Junior PHP / JS developer (I hope I will stay in this position and develop), but still I don’t want to move away from the database and SQL.
Plus to my background, there is some knowledge of Python (of course, I can’t pull it on junior, but at least something). I would like to hear the comments of those who are connected with SQL development. Thank you for reading the question

Answer 1

Probably, you need to know everything and indefinitely. I also work with PostgreSQL, for development and administration, in my bitter experience, you need to know:
In general, watch videos and read pgconf talks and PostgresPro documentation, it helps a lot to keep abreast of the latest trends.

Answer 2

Before developing competencies in any particular DBMS technology, you must first upgrade in database theory.
What are sets. Operations on sets. Entities (fields, tuples, tables, indexes, sequences, transactions, etc.). Table links (types and types of links). Access to data, etc.
And only then choose or not choose a specific technology.
And sometimes people with PLSQL experience come, like they write code and know standard functions.
And about the left / right connection, no gugu.
Added: I forgot to write about normal forms

Answer 3

you already have experience with oracle - develop in it. a good oracloid is an expensive thing.

Answer 4

Correctly create a data warehouse, taking into account the requirements of business logic.
Sometimes - a specific search is needed, sometimes - a quick addition of records.
These concepts must be clearly distinguished and correctly applied.
And, of course, to be able to write competent stored procedures that will make life easier for both the person who works with the database and those who work with this database through these procedures.