Linq为什么慢？ [英] Why is Linq slower?
问题描述
嗨！
测试som Linq-expressions并尝试测量性能和
将它与Linq之前的编程进行比较。
以下两种方法功能相同，但非Linq方法的价格是
的两倍。
public List< ConferenceRoomOldWay（int minimumSeatingCapacity）
{
列表< ConferenceRoomavailableRooms =新列表< ConferenceRoom>（）;
foreach（会议室房间）
{
if（room.SeatingCapacity> = minimumSeatingCapacity）
availableRooms.Add（room）;
}
返回可用房间;
}
公共列表< ConferenceRoomNewWay（int minimumSeatingCapacity）
{
返回（从房间的房间
，其中room.SeatingCapacity> = minimumSeatingCapacity
选择房间）.ToList（）;
}
PS。
简单明了：
达teTime start = DateTime.Now;
for（int i = 0;我< 1000000; i ++）
rooms.OldWay（8）;
Console.WriteLine（（DateTime.Now - start）.Ticks）;
....来衡量表现（一遍又一遍地重复测试）。
结果：
非Linq：约6 300 000蜱
Linq：ca。 3 100 000
为什么Linq更慢？
谢谢
/ Paul
结果：
Non-Linq：ca。 6 300 000蜱
Linq：ca。 3 100 000
我在这里缺少什么？更少的嘀嗒声实际上意味着它更快，对吧？
-Jeroen
抱歉结果如下：
结果：
Linq：ca。 6 300 000蜱
非Linq：ca。 3 100 000
嗨！
测试som Linq表情并尝试测量性能和
将它与Linq之前的编程进行比较。
以下两种方法功能相同，但非Linq方法的速度是b / b
的两倍。
public List< ConferenceRoomOldWay（int minimumSeatingCapacity）
{
List< ConferenceRoomavailableRooms = new List< ConferenceRoom>（）;
foreach（会议室房间）
{
if（room.SeatingCapacity> = minimumSeatingCapacity）
availableRooms.Add（room）;
}
返回可用房间;
}
public List< ConferenceRoomNewWay（int minimumSeatingCapacity）
{
返回（从房间的房间
，其中room.SeatingCapacity> = minimumSeatingCapacity
sel等房间）.ToList（）;
}
PS。
只是简单明了：
DateTime start = DateTime.Now;
for（int i = 0;我< 1000000; i ++）
rooms.OldWay（8）;
Console.WriteLine（（DateTime.Now - start）.Ticks）;
....来衡量表现（一遍又一遍地重复测试）。
结果：
非Linq：约6 300 000蜱
Linq：ca。 3 100 000
为什么Linq更慢？
谢谢
/ Paul
对不起，刚刚发布了一条回复说我混合了结果。
它应该是副verca。
谢谢
" Jeroen"写道：
结果：
非Linq：ca。 6 300 000蜱
Linq：ca。 3 100 000
我在这里缺少什么？更少的蜱真的意味着它更快，对吧？
-Jeroen
Hi!
Testing som Linq-expressions and tried to measure performance and
compare it to pre-Linq programming.
The folloing two methods are functional equal but the non-Linq one is
twice as fast.
public List<ConferenceRoomOldWay(int minimumSeatingCapacity)
{
List<ConferenceRoomavailableRooms = new List<ConferenceRoom>();
foreach (ConferenceRoom room in rooms)
{
if (room.SeatingCapacity >= minimumSeatingCapacity)
availableRooms.Add(room);
}
return availableRooms;
}
public List<ConferenceRoomNewWay(int minimumSeatingCapacity)
{
return (from room in rooms
where room.SeatingCapacity >= minimumSeatingCapacity
select room).ToList();
}
PS.
Just did a plain and simple:
DateTime start = DateTime.Now;
for (int i = 0; i < 1000000; i++)
rooms.OldWay(8);
Console.WriteLine((DateTime.Now - start).Ticks);
....to mesaure the performance (Did repeate the test over and over).
Results:
Non-Linq: ca. 6 300 000 ticks
Linq: ca. 3 100 000
Why is Linq slower?
Thanks
/Paul
Results:Non-Linq: ca. 6 300 000 ticks
Linq: ca. 3 100 000What am I missing here? Less ticks actually means it''s faster, right?
-Jeroen
Sorry mixed the results:
Results:
Linq: ca. 6 300 000 ticks
Non-Linq: ca. 3 100 000
"pa**********@hotmail.com" wrote:
Hi!
Testing som Linq-expressions and tried to measure performance and
compare it to pre-Linq programming.
The folloing two methods are functional equal but the non-Linq one is
twice as fast.
public List<ConferenceRoomOldWay(int minimumSeatingCapacity)
{
List<ConferenceRoomavailableRooms = new List<ConferenceRoom>();
foreach (ConferenceRoom room in rooms)
{
if (room.SeatingCapacity >= minimumSeatingCapacity)
availableRooms.Add(room);
}
return availableRooms;
}
public List<ConferenceRoomNewWay(int minimumSeatingCapacity)
{
return (from room in rooms
where room.SeatingCapacity >= minimumSeatingCapacity
select room).ToList();
}
PS.
Just did a plain and simple:
DateTime start = DateTime.Now;
for (int i = 0; i < 1000000; i++)
rooms.OldWay(8);
Console.WriteLine((DateTime.Now - start).Ticks);
....to mesaure the performance (Did repeate the test over and over).
Results:
Non-Linq: ca. 6 300 000 ticks
Linq: ca. 3 100 000
Why is Linq slower?
Thanks
/Paul
Sorry, just posted a reply saying that I mixed the results.
Its supposed to be vice-verca.
thanks
"Jeroen" wrote:
Results:
Non-Linq: ca. 6 300 000 ticks
Linq: ca. 3 100 000
What am I missing here? Less ticks actually means it''s faster, right?
-Jeroen
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