liquibase-core/src/main/java/liquibase/database/core/DB2Database.java
public boolean supportsBooleanDataType() {
		if (getConnection() == null)
			return false; /// assume not;
		try {

			final Integer fixPack = getDb2FixPack();

			if (fixPack == null)
				throw new DatabaseException("Error getting fix pack number");

			return getDatabaseMajorVersion() > 11
					|| getDatabaseMajorVersion() == 11 && getDatabaseMinorVersion() >= 1 && fixPack.intValue() >= 1;

		} catch (final DatabaseException e) {
			return false; // assume not
		}
	}
public boolean supportsBooleanDataType() {
		if (getConnection() == null)
			return false; /// assume not;
		try {

			final Integer fixPack = getDb2FixPack();

			if (fixPack == null)
				throw new DatabaseException("Error getting fix pack number");

			return getDatabaseMajorVersion() > 11
					|| getDatabaseMajorVersion() == 11 && getDatabaseMinorVersion() >= 1 && fixPack.intValue() >= 1;

		} catch (final DatabaseException e) {
			return false; // assume not
		}
	}
boolean data type column are allowed for versions >= 11.1.1.1
@return