English 中文(简体)
如何使InMemory.db成为内存映射文件并将其用作MFC中的数据库
原标题:How to make InMemory.db a Memory mapped file and use it as database in MFC

我不得不在我的项目中使用InMemory.db,但性能很慢——InMemory_db的大小是10MB。有些查询要检索30000多条记录,需要花费大量时间。他们有什么办法可以提高我的表现吗?

如何使InMemory.db成为内存映射文件,并将其用作MFC中的数据库。举个例子会很有帮助。

感谢Space_C0wb0y

创建.db文件的原因是为了将文件分发给不同的用户。

我想在内存中加载这个(InMemory.db)文件并使用该文件,或者以任何方式使用.db文件创建内存中的数据库。

查询如下

Select 
    ltoken, date_mm, Vcontract_name, price, quantity, 
    field1, field2, field3, field4, field5, field6, field7, 
    field8, field9, field10, field11, field12....., fieldn 
from contract

谢谢Steve Townsend

问题是这个.db文件是由客户端提供的,我应该使用它,所以不能更改数据库中的模式或任何东西

我只能通过打开与该文件的连接来直接使用该文件。

我不知道如何在内存中加载这个文件

我在上面搜索了一下,发现他们是我可以在内存中加载这个文件并将其用作数据库的方法

但我没有成功,所以有人能帮我把这个文件加载到内存中吗?任何例子都会有帮助

问题回答

这种大小的数据库应该可以在任何Windows桌面上完全缓存,而无需做任何额外的工作。

在数据库之前检查SQL和架构(尤其是表索引)。





相关问题
Undefined reference

I m getting this linker error. I know a way around it, but it s bugging me because another part of the project s linking fine and it s designed almost identically. First, I have namespace LCD. Then I ...

C++ Equivalent of Tidy

Is there an equivalent to tidy for HTML code for C++? I have searched on the internet, but I find nothing but C++ wrappers for tidy, etc... I think the keyword tidy is what has me hung up. I am ...

Template Classes in C++ ... a required skill set?

I m new to C++ and am wondering how much time I should invest in learning how to implement template classes. Are they widely used in industry, or is this something I should move through quickly?

Print possible strings created from a Number

Given a 10 digit Telephone Number, we have to print all possible strings created from that. The mapping of the numbers is the one as exactly on a phone s keypad. i.e. for 1,0-> No Letter for 2->...

typedef ing STL wstring

Why is it when i do the following i get errors when relating to with wchar_t? namespace Foo { typedef std::wstring String; } Now i declare all my strings as Foo::String through out the program, ...

C# Marshal / Pinvoke CBitmap?

I cannot figure out how to marshal a C++ CBitmap to a C# Bitmap or Image class. My import looks like this: [DllImport(@"test.dll", CharSet = CharSet.Unicode)] public static extern IntPtr ...

Window iconification status via Xlib

Is it possible to check with the means of pure X11/Xlib only whether the given window is iconified/minimized, and, if it is, how?

热门标签