Fixing missing database errors in DaVinci Resolve

Upon launching DaVinci Resolve you may see the following error:

"Resolve did not locate a compatible or upgradable database."

Clicking past it shows an empty project view.

There are several possible causes including database corruption but a common one is caused by your PostgreSQL database being too large. This can cause PostgreSQL to request more shared memory than is allowed by OS X or Linux.

To determine the exact error on OS X, you can launch the Start Server app in your /Applications/PostgreSQL folder. If it fails to launch it will show an error message after about a minute or so. On Ubuntu the equivalent command would be sudo service postgresql start.

The error may not have the exact wording shown above but will be labeled "could not created shared memory segment".

There are two ways to fix this problem - either permanently or temporarily until your next reboot. I'd recommend trying the temporary option first because if something goes wrong you can just restart to fix it.

Temporary Fix

1. Enter the following command into the Terminal located in /Applications/Utilities:

sudo sysctl -w kern.sysv.shmmax=41943040

You'll need to enter your admin password after typing this.

2. Launch the Start Server app or type sudo service postgresql start on Ubuntu. If all went well, it should not report an error and Resolve should be able to see the database when you relaunch it.

3. If you still get an error, try the command again with a higher value then repeat Step 2. The memory limit is specified in bytes so multiply the number of megabytes by 1024 twice. PostgreSQL documentation recommends you use 1/4 of the available memory for this, although I was able to get it working with much less.

Permanent Fix

1. Back up the file /etc/sysctl.conf.

2. Use the following command to edit the file:

sudo nano /etc/sysctl.conf

3. Add the following line (or edit it if it already exists):

kern.sysv.shmmax=41943040

4. Press Ctrl + O to save the file, then reboot.

5. Resolve should now be able to see the database. If it can't, try increasing the memory limit further and reboot.

If you get into problems and your system refuses to boot, either boot into safe mode or use target disk mode to copy the backup file and then reboot.