# previews.lrdata - Can I just delete it??



## stayathomedad (Nov 23, 2010)

My previews.lrdata is over 6GB... 

Can I just delete it?

Will LR3 simply recreate the file at start up?

Will the only downside be having to rerender previews??


Thanks!


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## matsmithphotog (Nov 23, 2010)

[quote author=stayathomedad link=topic=11672.msg78425#msg78425 date=129'488394]
My previews.lrdata is over 6GB... 

Can I just delete it?

Will LR3 simply recreate the file at start up?

Will the only downside be having to rerender previews??


Thanks!
[/quote]

Don't delete it. Instead go to the menu:

Library &gt; Previews &gt; Discard 1:1 Previews.

Close LR and wait a few seconds.

If the previews directory has reduced in size, you're good to go.

If not, don't bother deleting the directory anyway. It will just recreate standard sized previews when you re-launch. These are required for displaying your images within LR.

1:1 previews are useful for looking quickly at images at their actual size. They are not required to be rendered for the whole catalog at any given time, so you can save space by getting rid. Use the menu in LR to do this.

Standard previews are useful for looking quickly at images in your catalog, not necessarily at actual size. This is required for normal LR use.

In general, it's not the best idea to delete files created by LR outside of LR itself. Whilst LR is intelligent enough to keep up with this and as you say rebuild files, re-render previews, etc., you are far more likely to hit upon a bug in the software when you are doing this because it's usually outside the bounds of normal software testing. (I'm speaking generally here.)

If you are worried specifically about file fragmentation in the previews directory caused over a long time (a valid concern) then use the File &gt; "optimize catalog" menu.

There is also the option to purge the camera raw cache (preferences) and also the option to set the resolution of your standard previews (catalog settings), depending on what screen you use the most.


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## Victoria Bampton (Nov 23, 2010)

Mat's advice is good - LR would have to rebuild them again, so they'd probably be as big again fairly quickly.

That said, to directly answer your last 2 questions, yes and yes.


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## Graeme Brown (Nov 23, 2010)

Does the optimise function remove standard previews of files which have been deleted from the catalog, or does that happen automatically when you delete them?


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## johnbeardy (Nov 23, 2010)

I don't think so. Optimise simply works over the SQL database, with a VACUUM statement and integrity checks and index rebuilds.


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## Graeme Brown (Nov 23, 2010)

That's what I thought, so if you're in the habit of deleting lots of files it might be worth deleting and recreating the preview file every few months or something to tidy it up. With 1''k+ files in my catalog though the rebuild could take a looooooong time, so I'm not planning to try it any time soon.


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## matsmithphotog (Nov 23, 2010)

[quote author=Graeme Brown link=topic=11672.msg78443#msg78443 date=129'5'6539]
Does the optimise function remove standard previews of files which have been deleted from the catalog, or does that happen automatically when you delete them?
[/quote]

When you delete an image from within LR, this removes the associated previews for this image as well as the other associated LR database data.

If you have removed the image manually (i.e. deleted it in the OS, or removed it in some other way not using LR) then

a) don't
b) use the menu Library &gt; "Find missing photos" to find images for which you may have removed *not* in LR but that still exist in the LR catalog, then (carefully) remove these images from Lightroom too.
c) now run the optimize catalog

I say *carefully* because:

a) if you use removable drives, or drives on a network that may be offline, you don't want to remove these from your catalog, as you want them for when the drive is reconnected
b) once I accidentally deleted a few files (they were personal files - holiday pictures actually - I don't have accidents with clients' files!) and was mighty glad that the standard previews existed within LR as this enabled me to take a screencap and re-write the files that way. Sure it wasn't the original resolution but it was nice to find a way of getting one or two images back

With the above caveat "always exercise caution removing and deleting files, images, etc.", the way to minimize the amount of data LR takes up is:

- Remove missing files from within LR
- Don't worry about images that were previously in LR but are no longer - their preview data is long gone
- Discard 1:1 previews
- Optimise your catalog

Done.


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## Victoria Bampton (Nov 23, 2010)

[quote author=matsmithphotog link=topic=11672.msg78453#msg78453 date=129'518272]
When you delete an image from within LR, this removes the associated previews for this image as well as the other associated LR database data.
[/quote]

It *should* do, but stray previews have been known to get left behind even after deleting within LR.


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## Graeme Brown (Nov 23, 2010)

That's what I assumed, but one should never assume, especially when one has a Victoria available 8)


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## RikkFlohr (Nov 23, 2010)

Victoria's book was the first book on my i-Pad. It goes with me everywhere!


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## Graeme Brown (Nov 23, 2010)

Me too. I read it in bed.


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## Victoria Bampton (Nov 23, 2010)

Sends you to sleep Graeme!?!?


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## Graeme Brown (Nov 23, 2010)

[quote author=Victoria Bampton link=topic=11672.msg78468#msg78468 date=129'542'84]
Sends you to sleep Graeme!?!?  
[/quote]

Certainly not!

Although I do get funny looks from my wife when I tell her I'm off to bed with Victoria


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## sizzlingbadger (Nov 24, 2010)

My wife is called Victoria so I don't have to be too secretive


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