Suppose we want to read some records (separated by new line for example) which stored in CLOB column in Oracle database.
Most solutions recommend reading CLOB data chunk by chunk and for each chunk read some records.
The question is, when we execute the following query
SELECT clob_column
INTO v_clob
FROM myTable
WHERE some_condition;
the clob_column is fetched to v_clob variable, and it means it is fetched from database to main memory (I think so, maybe NOT). So why it is necessary to chunk v_clob? What is the benefit?
(Because often when the source is secondary and slow storage, we chunk the data)
Based on my understanding of how CLOB works on Oracle.
Fetching a CLOB into a variable retrieves only a locator, not the full content. So chunking is necessary to efficiently read large data, prevent memory overflow, handle VARCHAR2 size limits, and improve performance.