Have you ever experienced this?

• 😱 "Who wrote this query?" : 500 lines of just SELECT statements... 10 JOINs... You spend the whole day trying to understand it.

• 😭 "Just one condition changed..." : Are you digging through Excel, Python, and Java code to modify SQL queries one by one?

• 🐢 "Batch takes 5 hours?" : Batch jobs that run all night because data is extracted and processed in the application.

"Why do major corporations like Samsung still use PL/SQL in their operations?" Compress those thousands of lines of spaghetti queries into a single 'procedure' and go home on time.

"If you stop at SQL basics, you're just a 'data viewer'. Learn PL/SQL and you become a 'data architect' who handles data with complete mastery."

Why should you learn PL/SQL?

1. "With large-scale data, you waste all your time just pulling it out." (Performance Issue)

• Common belief: Trying to bring data into Python (Pandas) for processing.

• Fact (Problem): When transferring millions or tens of millions of records from the DB to your PC (Python), severe network bottlenecks and out of memory (OOM) issues occur.

• PL/SQL Solution: Instead of pulling data out, complete all processing (loops, conditional logic) inside the DB server and retrieve only the 'results'.

• Why you should learn it:

  "Does it take 10 minutes to load 10 million rows of data with Python? With PL/SQL processing on the server, it's done in 10 seconds. Analysts aren't people who wait for 'loading'."

2. "The Ultimate Preprocessing Automation" (Work Automation)

• Common belief: Every Monday, you receive the same Excel/CSV data and run the same Python code to clean it.

• Fact (Problem): 80% of analysis work is tedious 'data preprocessing'. Python scripts need to be run every time and are cumbersome to manage.

• PL/SQL's Solution: Once you create complex cleansing logic (handling missing values, standardizing date formats, removing outliers) as a 'Procedure', preprocessing is completed with a single command. You can even set up a scheduler so the preprocessing is done by the time you wake up.

• Why you should learn it:

  "Still manually doing repetitive daily data cleansing? With just one PL/SQL procedure, a single button press will get you home earlier."

3. "Just a 'Query Writer' vs 'Analyst Capable of Data Engineering'"

(Career Differentiation)

• Common belief: Analysts only need to be good at SELECT.

• Fact (Market Situation): Now everyone can do SELECT. Companies don't want people who simply 'view' data, but rather people who can directly build 'data pipelines (ETL)'. PL/SQL is a core tool for ETL that manipulates and moves data.

• The PL/SQL Solution: If you can handle PL/SQL, you can go beyond being a simple analyst and cover the realm of 'Data Engineer' as well. This is where your market value changes.

• Why You Should Learn:

  If you stop at SQL basics, you're just a 'data viewer'. Learn PL/SQL and you'll become a 'data architect' who can handle data with complete freedom.

Target Audience

• New Graduates/Job Seekers: Don't stop at "I know some SQL..." Interviewers (practitioners) light up when they see 'a new hire who can write procedures'.

• Junior Developers: If you're working overtime frequently due to complex queries, move the logic to the DB level and reclaim your 'on-time departure'.

• Data Analysts: Automate repetitive preprocessing tasks with PL/SQL and focus solely on analysis with automation.

This is the employment or job change status of students who have taken the main PL/SQL course.

Source: https://cafe.daum.net/oracleoracle/SDMs/441

You can master SQL by learning a total of 4 levels of skills as shown below. This course is a Level 2 course among them.

"In the field, 'easy-to-maintain code' is better than fancy techniques." As an Oracle expert, I will pass on to you the 'easy-to-maintain PL/SQL design principles' that have been proven in numerous projects. The essential gateway to SQL tuning - start now.