Your DPL database is loading slowly ? This might help


DPL has no maintenance tool for its database. If it has become slow on your system, you might try the following…

The DPL database is an SQLite database. So, it can be opened and maintained by any SQLite aware tool. Here’s how :

  1. Make a backup of your database after closing DPL.
  2. Download SQLite Expert Personal from this site (it’s free - Windows only) :
  3. Open you database in SQLite Expert.
  4. Use the Database | Check command in order to verify that it’s OK. If it’s not, stop here and exit.
  5. Use the Database | Vacuum command and wait until it’s done.
  6. Close SQLite Expert.
  7. Relaunch DPL. Unless the database has been built recently, it should now load much faster. This was the case for me.

This maintenance operation can also be done on a Lightroom catalog which is also an SQLite database.


By the way, since the SQLite engine is already embedded in DPL, it should be easy to add this command to the main menu.

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If it’s not OK, you can do a Repair but only with the Pro version of SQLite Expert. Other tools are probably available but I have always used SQLite Personal for the maintenance of my DPL and Lightroom databases without any problem.

In the past when my pc slowed downn I did remove the antivirus, avg?, completely and installed it again. I think that was also a to large db issue.
What does the vacuum command do?


This command cleans the database by copying its contents to a temporary database file and reloading the original database file from the copy. This eliminates free pages, aligns table data to be contiguous, and otherwise cleans up the database file structure.

Some reorganisation. I never worked with SQlite or other look alikes. I once bought the first release Access and when I tried to print 2 lines I had to wait for such a long time that I stopped . For myself I use DBF.


Is there also a version for Mac?

But DPL does… :slight_smile:

There’s no Mac version of SQLite Expert, I think.

There are other GUI interfaces for SQLite for the Mac but I don’t know which one implements the Vacuum command.

As a last resort, you can download the SQLite package for the Mac and run the Vacuum command from the command line.

And many others. :grinning:
I still wonder what’s meant with the word Vacuum.
Using a dbf structure one use the command Pack. Sounds like the oposite of Vacuum.


How exactly did the problem show?
How many RAWs you had?
What kind of disk was used for DB?
How long it took for vacuum cleaning?
Do you think DPL backup/delete/restore would do the job?

I have some 80,000 old RAWs but I plan a cleanup, deleting probably 80%.
In future, some 90% of loaded photos will get deleted.
The DB is on a recent Kingston NVMe SSD.
No problem so far, but my DPL is only two months old.

Read the topic name. Your dpl database is loading slowly ?. Question mark. Then this might help.
If you don’t experience this problem, than it’s not meant for you.


Probably related to the vacuum cleaner domestic device. Everything that should not be there is quickly removed.

It depends how DPL restores a backup database and how the backup was built. So, the process is apparently similar but you can’t be sure. A specialized software is probably preferable.

When I said “loading slowly”, I just meant slower than usual. Not only when DPL is starting but also when browsing folders. After I executed the “vacuum” process, I could browse much faster. But this may not apply to all situations. Anyway, this is a no-risk operation.

Thanks Patrick,
Just wondering if there was visible impact on exports.
I would guess it was few milliseconds per image, hence negligible.
My database may soon run into your problem,
but I don’t mind DPL starting 10 sec longer
and I don’t change folders that often.

Hi Patrick,

Regarding #3 (Open the database), which file is this? Can you advise the filename?

I found one file named CAFList7.db but when I tried to vacuum this file, it complained that the file was read only.

The file is PhotoLab.db, which can be logically found in the folder pointed to by the “DxO Photolab Database | Location” field in the General tab of the Preferences dialog box.


On my Windows 11 laptop, this was the location:
C:\Users<name>\AppData\Roaming\DxO\DxO PhotoLab 7\Database\

After running the vacuum process, my PL7 does seem to be loading photos faster. Thanks for the post.

A “vacuum” (which is not at all a standard DBA term) seems to be equivalent to a reorg, which can be achieved with an export and subsequent import.

But I seriously doubt it will yield much in the way of performance improvement. PL is a compute-bound program, spending most of its cycles calculating how an image would appear with the corrections applied. There is very little in the way of I/O as the program reads the corrections from the database, and I would be surprised if that’s more than 50K for any image.

With modern architectures of virtual memory, and machines built out to 32GB and more, the SQL*Lite engine (built into PL) will be cacheing as much of the DB as it can. Esoteric concepts such as page alignment and table contiguity really doesn’t apply for the small amount of I/O PL needs to do. It’s not recording thousands of transactions per second.

Regarding the symptoms reported by @Pat91, PL will slow down when you open a folder because it’s trying to calculate the proper rendering for all the images in that folder.

Off course I searched for that command in sql and its variants. The explanation of @Pat91 seems ok to me, an analog with the vacuum cleaner.
Last summer I updated my ram from 16 to 32. I don’t see any difference.