Photolab 9 database limits

eluohm · July 18, 2026, 2:35pm

My current PL9 database is 17.6 Gb. It takes a few minutes to open and display my photo library. My PC has the requirements for Photolab 9 (well over the minimum). the PL9 database is maintained on my SSD system 1 TB hard drive. My main photo folders are in an external USB3 hard drive. Once the photos are displayed, their processing speed is ok.

My question : is it possible to use multiple databases instead of a unique one, like one database per year ? This would maybe accelerate their opening in Photolab.

Or is there another way to improve the opening of my current database ?

platypus · July 18, 2026, 6:08pm

PhotoLab was not built to select from different databases like other apps. I can imagine a work around though - but it would go further than most users would want to go and it would require a very strict mode of operation from your side.

Concept:

make a backup and set it aside
trash the PL DB
repeat
- index a year
- give the DB a distinct name or location
until all years have an individual DB

Now, you’d have to convince PL to open with the DB for the year you want. Problem is, that this is complicated and all but relaxed way to work. And as soon as you select an “outside” folder, the DB will contain outside of the year images…

The simple way: Trash the DB before you start PL. This has some drawbacks, but many posters here work PL this way.

andras.csore · July 18, 2026, 8:05pm

Size more-or-less only related about PL editing ‘history entries’.

Example of my database - not so much photo in there: 10296.
Database size (overall): 400 MB. Some (not all) data table size:

Folders table (where the folder structure stored: 176 row, size: 0.01 MB
Items (photos / edited photos + virtual copies): 10296 / 71 MB
Sources (the files itself): 10036 / 1.8MB
HistoryEntries: 55342 / 322 MB → and 4340 photos has history entry (approx half of all photos) and only average 13 history entry per photo!

So, i think your 17GB database size due the ‘Advanced History’ - default like 50 for each edited photo (i leave it to default 50 in my database). Example: If no history, for 1GB database size, around 150 000 photo needed, for 17GB → around 2.5 million (may just 2 million)

is it possible to use multiple databases instead of a unique one, like one database per year

AFAIK in the file menu → Dxo Photolab database → backup ; restore. May you can do the trick with that.
However, i think it MAY has one small issue → preview cache. I guess, by default its not designed for multiple database. However, cache folder can be changed, so its can also works.

This would maybe accelerate their opening in Photolab.

I dont think its save too much if any. A few times i ‘debug’ what happen in DxO PL startup, folder opening, etc. and comment in the forum about that a few times. As far as i remember, of course its does database reads a lot during startup, but it was ‘not too much’ versus other things during PL startup (but i test with minimal history entries). For me currently like around 25-40 sec to start PL9 (all things in internal drives)

My main photo folders are in an external USB3 hard drive.

May that’s can be the thing behind startup performance.

Other: Data tabe size SQL query’s line by line (Windows database, i think in Mac the same, just folder names others (but similar)

Select count(*) from folders as itemcount_folders 
SELECT SUM("pgsize") FROM "dbstat" WHERE name='Folders' 
Select count(*) from Items as itemcount_items
SELECT SUM("pgsize") FROM "dbstat" WHERE name='Items'
Select count(*) from sources
SELECT SUM("pgsize") FROM "dbstat" WHERE name='Sources' 
Select count(*) from HistoryEntries as itemcount_history 
SELECT SUM("pgsize") FROM "dbstat" WHERE name='HistoryEntries'  
Select count(*) from (Select count(*) from HistoryEntries group by ItemId)  -- how many photos has History
Select avg(cnt1)  from (Select count(*) as cnt1 from HistoryEntries group by ItemId) -- average historyentry per photo

platypus · July 19, 2026, 9:19am

I usually look at the DB with