SQL database stores data in one single disk file. For processing the data in that file many temporary files are used by the database which includes DB-SHM file.
When the database is operating in WAL mode, all database connections related with a specific database file require some shared memory and this memory is used as index for another temporary file known as WAL file. The required shared memory is implemented by the database by using mmap() on DB-SHM file. The location of SHM file is same as that of database file. The main purpose of SHM file is to provide a block of shared memory for database processes.
In addition to the problem described above, i.e. the lack of the appropriate application to support the .DB-SHM file, there may be several reasons that cause problems with opening and operation of the data format:
A quite common problem is the lack of application in the appropriate version. Even if you have an application, with the help of which you should open the .DB-SHM file, you may have a problem with it because of its version. Perhaps in previous versions the application has not yet supported the .DB-SHM file, so download the update and check again.
If you have already installed the appropriate application, and it is the correct version, the file may not open correctly, because the operating system does not have information that this program supports the file. So you need to "show" which program the computer should use. To do this:
It also happens that the file you want to open is corrupt and therefore there is no such possibility. In this situation, you should find its different version, or ask a person from whom you got, to send it again.
There may be several reasons why you cannot open the file with .DB-SHM extension. Directly on this website you can find a solution of the most common problem with the .DB-SHM file – that you do not have on your computer the appropriate program to open the file.