Serious problem with 7z archive handling

[welhaux]

If you have a large 7z archive (413 MB, in my case) and you try to extract a single file, PA processes every file in the archive, just to extract the one file you’re after. :rolleyes:

[spwolf]

it is an solid archive, so as much as I remember, it shouldnt know anything about single files, right?

[welhaux]

@spwolf:

it is an solid archive, so as much as I remember, it shouldnt know anything about single files, right?

I don’t understand your comment. However, the same files, archived with the ZIP format (456 MB), permits a single file to be extracted in practically not time.

[spwolf]

7zip is an solid archive usually, which means all files are trated as one huge file. End result of this is better compression. As the downside, you can not add files to the archive, or update them. When you extract single files, if it is an solid archive, it probably needs to extract all files from same filestream (usually not whole archive).

zip is not an solid format, so same does not apply.

[welhaux]

@spwolf:

7zip is an solid archive usually, which means all files are trated as one huge file. End result of this is better compression.

I suppose this is the same case with .CAB? I was going to also test with a CAB archive, but it’s taking FOREVER to compress. 14 minutes has elapsed and I’m at only 25 %! :eek:

EDIT: I guess not. Creation of the .CAB archive (428 MB) completed about 14 minutes ago, and I was able to do the single file extraction pretty much as fast as with the ZIP archive.

I guess 7z is no good if you ever hope to extract single files from a large archive. :(

[TBGBe]

@welhaux:

I suppose this is the same case with .CAB? I was going to also test with a CAB archive, but it’s taking FOREVER to compress. 14 minutes has elapsed and I’m at only 25 %! :eek:

EDIT: I guess not. Creation of the .CAB archive (428 MB) completed about 14 minutes ago, and I was able to do the single file extraction pretty much as fast as with the ZIP archive.

I guess 7z is no good if you ever hope to extract single files from a large archive. :(

Yes, CAB is also a solid format (but as you found sometimes faster than 7z) - although the compression is usually not as good.

If you need to add or extract from 7z archives, just deactivate the option “Create Solid Archive”.

[welhaux]

@TBGBe:

If you need to add or extract from 7z archives, just deactivate the option “Create Solid Archive”.

Thanks for the info.

[jowood]

Try SQX. It also creates solid archives and can of course update such archives.

[welhaux]

@jowood:

Try SQX. It also creates solid archives and can of course update such archives.

Another compression format! :eek: Why can’t we all just get along? :cool:

Ivan & spwolf, any thoughts of adding SQX to the list? :p

[TBGBe]

@welhaux:

Ivan & spwolf, any thoughts of adding SQX to the list? :p

It is already in the Wishlist (among many, many others).

[spwolf]

@welhaux:

Another compression format! :eek: Why can’t we all just get along? :cool:

Ivan & spwolf, any thoughts of adding SQX to the list? :p

nope. there is nothing new there, another non open source format.

[spwolf]

@jowood:

Try SQX. It also creates solid archives and can of course update such archives.

works the same as every other solid format btw - if you want to update file, whole archive needs to be re-compressed, so basically it is hardly an updating :-). Same goes with extracting files, other files need to be extracted as well.