Limit Page Size Handling Shifts Between GoLand 2023.3 and 2024.2 for MySQL and PostgreSQL Drivers

Result Set Limiting in GoLand

The 'Limit page size' setting in GoLand is an advisory configuration. It does not guarantee a hard bound on the result set because it relies on the underlying JDBC driver's implementation of Statement.setMaxRows() or setFetchSize(). Whether the server returns the full set or a limited page depends entirely on the driver's capabilities and the database configuration.

Driver-Specific Behavior

Based on the architecture of the JDBC drivers mentioned:

• PostgreSQL (JDBC 42.7.3): Generally honors the limit. In GoLand 2024.2, the IDE leverages the driver's ability to use server-side cursors to fetch rows in chunks. However, this typically requires the connection to be in non-autocommit mode to maintain the cursor.
• MySQL (Connector/J 8.0.33): Frequently ignores setMaxRows() and may fetch the entire result set into client memory unless streaming is explicitly enabled. MySQL Connector/J often requires a specific fetchSize (e.g., Integer.MIN_VALUE) to trigger row-by-row streaming, which the 'Limit page size' setting does not always trigger automatically.

Version Shifts: 2023.3 vs 2024.2

Between version 2023.3 and 2024.2, JetBrains updated the database connectivity layer. While 2023.3 relied more heavily on injecting LIMIT clauses into the SQL for supported dialects, 2024.2 has shifted toward more standardized JDBC property handling. This means that for drivers that do not strictly implement setMaxRows(), you may see a regression where more rows are fetched than the page size suggests.

How to Force Reliable Pagination

If the IDE setting is being ignored by your driver, the only reliable way to bound the result set is to bypass the IDE's automation and use explicit SQL syntax:

1. For PostgreSQL: Use SELECT ... LIMIT 100 OFFSET 0;
2. For MySQL: Use SELECT ... LIMIT 100;

Verification and Diagnostics

To verify if the limit is being enforced at the network level rather than just the UI level, you can check the IDE's internal logs or use a network monitor. If the IDE is successfully communicating the limit, you will see the driver requesting specific fetch sizes.

Required Diagnostic: To provide a more precise recommendation for MySQL, please specify if you have useCursorFetch=true enabled in your JDBC connection properties, as this fundamentally changes how Connector/J handles page limits.