# Confusing "lrcat" Files



## kitjv (Jan 27, 2018)

Operating System:Mac OS 10.13.2
Exact Lightroom Version (Help menu > System Info): Lightroom Classic CC 7.1

I recently opened my Lightroom subfolder in my Mac's home folder. In addition to the "lrcat" file, there is a file named "lrcat-wal" & "lrcat.lock". Can someone tell me what these are? Thank you so much.


----------



## clee01l (Jan 28, 2018)

These two files only appear while LR is open.  The "lrcat.lock" file is a sentinel file that when present, prevents another instance of the LR App from opening this catalog. The "lrcat-wal" file was added (I think) with LR6 or CC and has something to do with SQLLite database  "write-ahead logging" function. It too goes away when you shout down LR correctly. SQLLite database file is your LR catalog file.


----------



## kitjv (Jan 28, 2018)

Oops...I was a bit trigger-happy with the above post. After searching the forum database, I now realize that these files are only temporary files while LR is running. Sorry.


----------

