How to join two tables in an Oracle database?

In Oracle database, two tables can be associated by using JOIN statement. There are various types of joins, including inner join, left join, right join, and full join.

1. Inner Join: Returns records from two tables that meet the connection conditions.
   Syntax: SELECT * FROM Table1 INNER JOIN Table2 ON Table1.column = Table2.column
2. LEFT JOIN: Returns all records from Table 1 along with records from Table 2 that meet the join condition.
   Syntax: SELECT * FROM Table1 LEFT JOIN Table2 ON Table1.column = Table2.column.
3. Right join: return all records from table 2 and any matching records from table 1 based on the join condition. Syntax: SELECT * FROM table1 RIGHT JOIN table2 ON table1.column = table2.column.
4. Full Join: Returns all records from both tables, filling in with NULL if there is no match.
   Syntax: SELECT * FROM Table1 FULL JOIN Table2 ON Table1.column = Table2.column

In actual use, choose the appropriate type of connection based on specific needs, such as using outer joins to return all records or inner joins to return matching records. Additionally, indexes can be used to speed up the connection process for improved query efficiency.