### Description

Tracking total hits sometimes has a non-negligible impact on performance. We should disable it when not strictly required.
x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/execution/search/SourceGenerator.java
private SourceGenerator() {}
    public static SearchSourceBuilder sourceBuilder(QueryContainer container, QueryBuilder filter, Integer size) {
        QueryBuilder finalQuery = null;
        
        if (container.query() != null) {
            if (filter != null) {
                finalQuery = boolQuery().must(container.query().asBuilder()).filter(filter);
            } else {
                finalQuery = container.query().asBuilder();
            }
        } else {
            if (filter != null) {
                finalQuery = boolQuery().filter(filter);
            }
        }
        final SearchSourceBuilder source = new SearchSourceBuilder();
        source.query(finalQuery);
        QlSourceBuilder sortBuilder = new QlSourceBuilder();
        
        
        
        container.fields().forEach(f -> f.extraction().collectFields(sortBuilder));
        sortBuilder.build(source);