OF-3364: Limit MUC history reload query at the database level

[guusdk]

MUCPersistenceManager#loadHistory previously fetched all rows since the configured reload window and then scrolled/trimmed the ResultSet client-side to keep only the last maxNumber messages.

This relied on scrollable, TYPE_SCROLL_INSENSITIVE result sets, which are not reliably supported across all database backends (e.g. disabled outright for CockroachDB), and could transfer far more data than was ultimately retained for rooms with long histories.

Instead, build the query dynamically using DbConnectionManager's result-set-limit facilities (LIMIT / TOP / FETCH FIRST ... ROWS ONLY, per database type) so the limit is pushed down to the database.

Also adds debug logging around the reload window and returned row count to make future over-fetching easier to spot.

[coderabbitai]

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Reviewing files that changed from the base of the PR and between 8252a81 and e432534.

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• xmppserver/src/main/java/org/jivesoftware/openfire/muc/spi/MUCPersistenceManager.java

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📝 Walkthrough

Walkthrough

loadHistory now uses dynamically built SQL instead of a fixed query and scrollable result sets. The query applies database-specific TOP, LIMIT, or FETCH FIRST syntax when a maximum message count is set. Parameter binding adapts to the selected syntax. Limited results are fetched in descending time order, then reversed before insertion so room history remains chronological. Debug logging reports loaded message counts and applied limits.

Merge Risk: ⚪ Minimal · up to e4325

MUC history loading now limits database results directly while retaining chronological message order, reducing unnecessary data transfer without an identified merge-blocking behavior risk.

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description check	✅ Passed	The pull request description directly explains the changes to MUCPersistenceManager#loadHistory, including database-level result limits, removal of scrollable result-set reliance, reduced data transfe…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[github-actions]

Successfully created backport PR for 5.1:

• [Backport 5.1] OF-3364: Limit MUC history reload query at the database level #3488