If you enable hibernate.query.in_clause_parameter_padding in {{persistence.xml}}and then execute the following query with 1900 parameters:

select m from MyEntity m where m.id in ?1

You will get this error ORA-01795: maximum number of expressions in a list is 1000.

The issue lies in AbstractSqlAstTranslator: if there are more listExpressions than inExprLimit and inClauseParameterPaddingEnabled is true then bindValueMaxCount is calculated as ceilingPowerOfTwo( bindValueCount % inExprLimit ). In our example this is ceilingPowerOfTwo(1900 % 1000) == 1024.

This result is then used to pad the last in clause without checking inExprLimit again:

https://github.com/hibernate/hibernate-orm/blob/6746c30275b6600622d82613dc70b1fbf97a2fdf/hibernate-core/src/main/java/org/hibernate/sql/ast/spi/AbstractSqlAstTranslator.java#L6884-L6891

		if ( inClauseParameterPaddingEnabled ) {
			final Expression lastExpression = itemAccessor.apply( listExpressions.get( listExpressions.size() - 1 ) );
			for ( ; `; itemNumber++ ) {
				appendSql( separator );
				lastExpression.accept( this );
				separator = COMA_SEPARATOR;
			}
		}

A simple fix would be to change the condition of this for-loop to itemNumber < Math.min(bindValueMaxCount, inExprLimit), but I feel like the whole calculation could be simplified.