public String getValueCName(String metricsName) {
        final String valueCName = findColumn(metricsName).valueCName;
        return columnNameOverrideRule.getOrDefault(valueCName, valueCName);
    }
Fetch the value column name of the given metrics name.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/storage/annotation/ValueColumnMetadata.java