说我有这些查询
// Linq
var allRecords = session.Query<Table1P>().FetchMany(x => x.Table2).FetchMany(x => x.Table3).FetchMany(x => x.Table4).FetchMany(x => x.Table6).ToList();
// Hql
string hqlQuery = @"from Table1 tbl1
left join fetch tbl1.Table2 tbl2
left join fetch tbl1.Table3
left join fetch tbl1.Table4
left join fetch tbl1.Table6
left join fetch tbl2.Table5s";
在上面的例子中，我需要做所有这些连接来停止延迟加载并进行急切加载。现在，这将在nhibernate探查器中产生一个关于太多连接的警报。
http://nhprof.com/Learn/Alerts/TooManyJoins
因此，停止此警报的一种方法是拆分连接。并做多个查询。这就是我想要做的。然而，与此同时，我一直在阅读未来的功能，我认为这将允许我打破查询（停止太多的连接）但仍然一次执行它。
修改 的
我一直在尝试使用ToFuture，并且在尝试限制数据返回时发现速度较慢（如果我尝试将所有内容都恢复，那么它会更快，因为它不会崩溃）。
var allRecords = session.Query<Table1P>().FetchMany(x => x.Table2).FetchMany(x => x.Table3).FetchMany(x => x.Table4).FetchMany(x => x.Table6).Take(3000).ToList();
// result (2.731 seconds), row count 3000, duration 8 ms/ 2013 ms
select TOP (3000 /* @p0 */) table1p0_.Id as Id1_0_,
table2x1_.Id as Id2_1_,
table3x2_.Id as Id3_2_,
table4x3_.Id as Id4_3_,
table6x4_.Id as Id6_4_,
table1p0_.F1 as F2_1_0_,
table1p0_.F2 as F3_1_0_,
table1p0_.F3 as F4_1_0_,
table2x1_.F1 as F2_2_1_,
table2x1_.F2 as F3_2_1_,
table2x1_.F3 as F4_2_1_,
table2x1_.Table1_id as Table5_2_1_,
table2x1_.Table1_id as Table5_0__,
table2x1_.Id as Id0__,
table3x2_.F1 as F2_3_2_,
table3x2_.F2 as F3_3_2_,
table3x2_.F3 as F4_3_2_,
table3x2_.Table1_id as Table5_3_2_,
table3x2_.Table1_id as Table5_1__,
table3x2_.Id as Id1__,
table4x3_.F1 as F2_4_3_,
table4x3_.F2 as F3_4_3_,
table4x3_.F3 as F4_4_3_,
table4x3_.Table1_id as Table5_4_3_,
table4x3_.Table1_id as Table5_2__,
table4x3_.Id as Id2__,
table6x4_.F1 as F2_6_4_,
table6x4_.F2 as F3_6_4_,
table6x4_.F3 as F4_6_4_,
table6x4_.Table1_id as Table5_6_4_,
table6x4_.Table1_id as Table5_3__,
table6x4_.Id as Id3__
from Table1 table1p0_
left outer join [Table2] table2x1_
on table1p0_.Id = table2x1_.Table1_id
left outer join [Table3] table3x2_
on table1p0_.Id = table3x2_.Table1_id
left outer join [Table4] table4x3_
on table1p0_.Id = table4x3_.Table1_id
left outer join [Table6] table6x4_
on table1p0_.Id = table6x4_.Table1_id
使用ToFuture
// result (4.808 seconds), row count 6944 / 75/ 374, duration 1ms / 4022 ms
// will load the Entities with Table2 fetched
var allRecords = session.Query<Table1P>()
.FetchMany(x => x.Table2)
.ToFuture()
.Take(3000);
// will load the Entities with Table3 fetched
session.Query<Table1P>()
.FetchMany(x => x.Table3)
.ToFuture();
// will load the Entities with Table4 fetched
session.Query<Table1P>()
.FetchMany(x => x.Table4)
.ToFuture();
// will load the Entities with Table6 fetched
session.Query<Table1P>()
.FetchMany(x => x.Table6)
.ToFuture();
// will trigger all queries at once and the session cache will make sure,
// that the results of all queries fill the same Entities
allRecords.ToList();
select table1p0_.Id as Id1_0_,
table2x1_.Id as Id2_1_,
table1p0_.F1 as F2_1_0_,
table1p0_.F2 as F3_1_0_,
table1p0_.F3 as F4_1_0_,
table2x1_.F1 as F2_2_1_,
table2x1_.F2 as F3_2_1_,
table2x1_.F3 as F4_2_1_,
table2x1_.Table1_id as Table5_2_1_,
table2x1_.Table1_id as Table5_0__,
table2x1_.Id as Id0__
from Table1 table1p0_
left outer join [Table2] table2x1_
on table1p0_.Id = table2x1_.Table1_id;
select table1p0_.Id as Id1_0_,
table3x1_.Id as Id3_1_,
table1p0_.F1 as F2_1_0_,
table1p0_.F2 as F3_1_0_,
table1p0_.F3 as F4_1_0_,
table3x1_.F1 as F2_3_1_,
table3x1_.F2 as F3_3_1_,
table3x1_.F3 as F4_3_1_,
table3x1_.Table1_id as Table5_3_1_,
table3x1_.Table1_id as Table5_0__,
table3x1_.Id as Id0__
from Table1 table1p0_
left outer join [Table3] table3x1_
on table1p0_.Id = table3x1_.Table1_id;
select table1p0_.Id as Id1_0_,
table4x1_.Id as Id4_1_,
table1p0_.F1 as F2_1_0_,
table1p0_.F2 as F3_1_0_,
table1p0_.F3 as F4_1_0_,
table4x1_.F1 as F2_4_1_,
table4x1_.F2 as F3_4_1_,
table4x1_.F3 as F4_4_1_,
table4x1_.Table1_id as Table5_4_1_,
table4x1_.Table1_id as Table5_0__,
table4x1_.Id as Id0__
from Table1 table1p0_
left outer join [Table4] table4x1_
on table1p0_.Id = table4x1_.Table1_id;
select table1p0_.Id as Id1_0_,
table6x1_.Id as Id6_1_,
table1p0_.F1 as F2_1_0_,
table1p0_.F2 as F3_1_0_,
table1p0_.F3 as F4_1_0_,
table6x1_.F1 as F2_6_1_,
table6x1_.F2 as F3_6_1_,
table6x1_.F3 as F4_6_1_,
table6x1_.Table1_id as Table5_6_1_,
table6x1_.Table1_id as Table5_0__,
table6x1_.Id as Id0__
from Table1 table1p0_
left outer join [Table6] table6x1_
on table1p0_.Id = table6x1_.Table1_id;
从nhibernate探查器获取的查询和时间。通过使用其中一组代码运行测试，记录结果，停止.net开发服务器，然后运行另一组代码来运行测试。
表1 - 6200行 表2-744行 表3 - 75行 表4 - 374行 表6 - 300行
几乎表1对所有其他表都有一对多。
答案 0 :(得分：2)
// will load the Entities with Table2 fetched
var allRecords = session.Query<Table1P>()
.FetchMany(x => x.Table2)
.ToFuture();
// will load the Entities with Table3 fetched
session.Query<Table1P>()
.FetchMany(x => x.Table3)
.ToFuture();
// will load the Entities with Table4 fetched
session.Query<Table1P>()
.FetchMany(x => x.Table4)
.ToFuture();
// will load the Entities with Table6 fetched
session.Query<Table1P>()
.FetchMany(x => x.Table6)
.ToFuture();
// will trigger all queries at once and the session cache will make sure,
// that the results of all queries fill the same Entities
allRecords.ToList();
变化
.ToFuture()
.Take(3000);
到
.Take(3000);
.ToFuture()
更新
// Hql
var allRecords = session.CreateQuery("from Table1 left join fetch tbl1.Table2")
.ToFuture<Table1>();
...
奇怪这比大联盟要慢。我现在不能在这里测试。可能在db中没有那么多行，多个结果集的开销大于扩展连接的开销。你可以在db中尝试更多数据吗？