


How to Efficiently Paginate Large JDBC Result Sets Without `rs.absolute()`?
Jan 02, 2025 pm 07:53 PMEfficient JDBC Pagination without Absolute Row Positioning
Problem:
You need to implement efficient pagination for large result sets in JDBC without using rs.absolute() or rownum/limit offset.
Approach:
Although JDBC does not natively provide pagination support, you can implement it efficiently by modifying your SQL query directly.
Solution:
-
Use Database-Specific Pagination Keywords:
Certain databases (e.g., MySQL, PostgreSQL) offer pagination-specific keywords like LIMIT and OFFSET. For example:
SELECT * FROM data LIMIT 50 OFFSET 0;
-
Subquery with Row Number (Oracle):
Oracle does not have a built-in pagination keyword. Instead, you can use a subquery with the ROWNUM pseudocolumn:
SELECT * FROM ( SELECT sub_data.*, rownum rnum FROM data sub_data ) WHERE rnum BETWEEN 1 AND 50;
Advantages of Database Pagination:
- Efficient: Database-specific pagination keywords leverage database optimizations for efficient result retrieval.
- Portable: Subquery approach ensures portability across databases, although it might be less efficient in some cases.
Alternative Approaches:
- Cache ResultSet: Fetch the entire result set and cache it in memory. This approach is suitable for small result sets but may not be feasible for large datasets.
- Streaming: Use a streaming API to process results incrementally, reducing memory usage. However, this approach is not supported by all JDBC drivers.
The above is the detailed content of How to Efficiently Paginate Large JDBC Result Sets Without `rs.absolute()`?. For more information, please follow other related articles on the PHP Chinese website!

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