问题描述
由于性能和可靠性的原因，我想使用WAL模式。但是我的环境没有mmap（）函数，所以我不能用WAL编译SQLite（WAL需要mmap（）。）。虽然设置 PRAGMA locking_mode = EXCLUSIVE 允许使用WAL而不使用mmap（）（在这种情况下，WAL-index是在堆内存上创建的，而不是共享文件），这不是好的解决方案对于管理多个数据库连接的应用程序。
I want to use WAL mode for the reason of performance and reliability. However my environment doesn't have mmap() function, so I can't compile SQLite with WAL (WAL needs mmap().). Although setting PRAGMA locking_mode=EXCLUSIVE allow use of WAL without mmap() (In this case, WAL-index is created on heap memory not shared file), it is not good solution for the applications that manage multiple database connections.
我在一个进程中使用SQLite与多个数据库连接（用于线程间并发），而mmap（）似乎只有用于进程间内存共享。因为我期望有一种方法在单进程环境中使用WAL而不使用mmap（）。但我找不到好的解决方案。是否有任何想法来解决这个问题？
I use SQLite with multiple database connections (for inter-thread concurrency) in one process, and mmap() seems to be only used for inter-process memory sharing. Since I expect there is a way to use WAL without mmap() in single-process environment. But I can't find the good solution. Are there any ideas to solve this problem?
谢谢。
推荐答案
SQLibrary中的代码总是为wal-index创建一个内存映射文件。
The code in the SQLibrary always creates a memory-mapped file for the wal-index.
如果要使用WAL而不使用mmap，则必须将该代码更改为请改用一个简单的共享内存块。
If you want to use WAL without mmap, you have to change that code to use a plain block of shared memory instead.
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