How to use SQL Tuning Advisor in Oracle SQL Developer?

Oracle SQL Developer -> Connections -> Right mouse click on desired database connection name (e.g. XE) -> Click "Open SQL Worksheet" -> Input and select SQL code block -> Right mouse click then select "SQL Tuning Advisor" or press "CTRL+F12" -> Lastly, analyze the result.

How to backup Oracle SQL Developer connection list?

Backup connection.xml file from SQL Developer Setup folder
e.g.
Oracle SQL Developer Version 17.3.1.279.0537

-> C:\Users\%USERNAME%\AppData\Roaming\SQL Developer\system17.3.1.279.0537\o.jdeveloper.db.connection\connections.xml

How to define "Code Templates" in SQL Developer?

e.g.
SQL DEVELOPER -> TOOLS -> PREFERENCES -> DATABASE -> SQL EDITOR CODE TEMPLATES -> Click "ADD TEMPLATE" button -> Input Id as "sl", Template as "select * from " -> OK

Usage:
Press "sl" and press "ctrl+space"

Output:
select * from 

How to show line number in SQL Developer?

Tools -> Preferences -> Code Editor -> Line Gutter -> Activate "Show Line Numbers" -> OK

How to solve SQL Developer redrawing problem on Windows?

Problem

Solution

Tools -> Preferences -> Lock and Feel -> Set Windows -> Click OK