What is the purpose of using join in Oracle?

In Oracle, JOIN is an operation used to combine data from two or more tables. This operation enables data to be extracted from multiple tables based on their relationship conditions, resulting in a combined result set.

There are several aspects to the function of the JOIN operation:

1. Performing a joint query for data allows for retrieving information from multiple tables simultaneously, reducing the need for separate queries and simplifying the querying process, resulting in decreased database load.
2. Achieving associations between tables: JOIN operation connects related data together based on the association conditions set between tables. By using the values of associated fields, relevant data can be retrieved in the result set, allowing for multi-table queries to be carried out.
3. Combine data: The JOIN operation allows for merging data from multiple tables to generate a result set, making it easier to perform operations such as data analysis, statistics, and comparisons.
4. Filter and screen data: By using a JOIN operation, data can be filtered and screened based on the associated conditions. Only the data that meets the criteria will be joined together and returned in the result set.

In conclusion, the JOIN operation is widely used in Oracle as it combines data from different tables, offering more comprehensive and robust data querying and analysis capabilities.