Database's Temp Tables or APEX Collections?

 Why should we not use the Database's temp table instead of APEX Collections? 

If you want to know more about the APEX Collections I suggest you read the article below link: 

https://lidagholizadeh.blogspot.com/2024/04/apex-collection.html

What are Oracle Temporary Tables?

Oracle Temporary Tables are database tables specifically designed to store temporary data for the duration of a session or transaction. The data in these tables is private to the session and is automatically removed either at the end of the transaction or the session, depending on how the table is defined. These tables are useful for scenarios where intermediate data needs to be stored and processed without being persisted permanently in the database.

CREATE GLOBAL TEMPORARY TABLE TEMP_INVOICE_DETAILS (
    ITEM_ID NUMBER,
    ITEM_NAME VARCHAR2(100),
    QUANTITY NUMBER,
    PRICE_PER_UNIT NUMBER,
    DISCOUNT NUMBER,
    TOTAL_PRICE NUMBER
) ON COMMIT DELETE ROWS; -- Data is cleared after each transaction.

👓 When to Use Oracle Temporary Tables

1. Complex Data Processing: Temporary tables are ideal for storing intermediate results during multi-step or complex data processing, such as calculations, transformations, or aggregations.

2. Large Datasets: They are useful for breaking down large datasets into manageable chunks for batch processing.

3. Avoiding Overhead on Permanent Tables: Storing transient data in permanent tables can lead to unnecessary overhead (locking, logging, and archiving). Temporary tables help avoid this.

4. Isolation of Session Data: When each user session needs to maintain its own isolated dataset without interfering with others.

5. Temporary Data Transformation: Before loading data into a permanent table, temporary tables can be used for staging and transformations.

👓 When Not to Use Temporary Tables

1. For session-specific or lightweight data needs, APEX Collections or PL/SQL collections might be more suitable.
2. If the data needs to persist beyond the session or transaction, use a permanent table.

Why should we not use the Database's temp table instead of APEX Collections?

Oracle APEX Collections are versatile, session-specific, in-memory data structures designed for temporary data storage and manipulation during a user's session. They function similarly to database tables but do not persist in the database, making them ideal for transient data needs. APEX Collections enable data sharing across pages within the same session, support efficient batch processing of large datasets, and allow data manipulation using PL/SQL procedures, making them valuable for scenarios like multi-step forms and temporary data handling.

    1. Session-Specific Scope

APEX Collections Each collection is tied to a specific user session, ensuring that data is isolated and secure between sessions. This eliminates the need to manually handle session identification or cleanup but Temporary Tables require additional handling to differentiate data between user sessions, such as using session identifiers, which can complicate queries and maintenance.

    

    2. Built-in APEX Integration

APEX Collections  Fully integrated into Oracle APEX, they can be easily accessed and manipulated using APEX-specific APIs, simplifying development but Temporary Tables: Require standard SQL or PL/SQL operations, which might not leverage APEX-specific optimizations.

    3. In-Memory Performance

APEX Collections Data resides in memory, resulting in faster access and manipulation, as no disk I/O is involved but Temporary Tables Data is written to and read from the database, which introduces additional overhead, especially for short-lived or frequently accessed data.

    4. No Database Schema Dependency

APEX Collections: They do not require database schema changes, making them more agile and adaptable for temporary or experimental data handling but for Temporary Tables You must create and maintain these tables in the database schema, which can complicate deployment and require DBA involvement.

    5. Automatic Cleanup

APEX Collections  Automatically cleaned up at the end of the user session, reducing the risk of orphaned or stale data but for Temporary Tables  You must explicitly manage cleanup to avoid clutter and potential conflicts.

   6. Resource Efficiency

APEX Collections: Consume fewer database resources since they operate in memory and avoid locking or contention issues but Temporary Tables Can create overhead on the database, especially if many sessions are active simultaneously.