### Description

Tracking total hits sometimes has a non-negligible impact on performance. We should disable it when not strictly required.
x-pack/plugin/sql/qa/server/single-node/src/javaRestTest/java/org/elasticsearch/xpack/sql/qa/single_node/CliExplainIT.java
assertThat(readLine(), startsWith("----------"));
        assertThat(readLine(), startsWith("Project[[test.test_field{f}#"));
        assertThat(readLine(), startsWith("\\_EsRelation[test][test_field{f}#"));
        assertEquals("", readLine());
        assertThat(command("EXPLAIN (PLAN OPTIMIZED) SELECT * FROM test"), containsString("plan"));
        assertThat(readLine(), startsWith("----------"));
        assertThat(readLine(), startsWith("Project[[test.test_field{f}#"));
        assertThat(readLine(), startsWith("\\_EsRelation[test][test_field{f}#"));
        assertEquals("", readLine());
        
        assertThat(command("EXPLAIN (PLAN EXECUTABLE) SELECT * FROM test"), containsString("plan"));
        assertThat(readLine(), startsWith("----------"));
        assertThat(readLine(), startsWith("EsQueryExec[test,{"));
        assertThat(readLine(), startsWith("  \"_source\" : false,"));
        assertThat(readLine(), startsWith("  \"fields\" : ["));
        assertThat(readLine(), startsWith("    {"));
        assertThat(readLine(), startsWith("      \"field\" : \"test_field\""));
        assertThat(readLine(), startsWith("    }"));
        assertThat(readLine(), startsWith("  ],"));
        assertThat(readLine(), startsWith("  \"sort\" : ["));
        assertThat(readLine(), startsWith("    {"));
        assertThat(readLine(), startsWith("      \"_doc\" :"));
        assertThat(readLine(), startsWith("        \"order\" : \"asc\""));
        assertThat(readLine(), startsWith("      }"));
        assertThat(readLine(), startsWith("    }"));
        assertThat(readLine(), startsWith("  ]"));
        assertThat(readLine(), startsWith("}]"));
        assertEquals("", readLine());
    }
    public void testExplainWithWhere() throws IOException {