Very large file sizes

Hullo, I have been using LibreCad for a few years now and have a recurring issue.  Deleting data from a .dfx does not reduce the file size, it's almost as if all historic data is stored.

This is fine, until I need to import multiple blocks into a drawing.  In this case, the size of the files becomes massive and unworkable.

Is there a way to remove unused data, or rebuild the database?

I have done a test run. New empty drawing saved is 18 kb, imported some blocks from library browser is 100 kb, deleted the visible drawing still 100kb, deleted from Block List is 21 kb, deleted the added layers is 18 kb again.
Have you missed to clear up the Block List?

Sorry, what do you mean by "Have you missed to clear up the Block List?"

Think, I've worked it out now.

I didn't know there was a block list and have lots of historic blocks being copied between my drawings!!

Cheers...

Is there any way of deleting multiple blocks from the list in one go.  It appears I have been accruing blocks for many years!!

In V 2.1.3 you can only select single blocks.
In the current 2.2.0 rc2 available as nightly version for Windows you can select multiple blocks as well as layers at one time.

It depends on your LibreCAD version.
in newer versions you can use CTRL and SHIFT key to select multiple lines in block list and then delete them all together.
Try it by clicking the top row and then click the bottom row with SHIFT key pressed.
When all blocks are selected, you can use the delete button to delete them all.
Don't worry, there will be a confirmation window before they are deleted.
If only one line stays selected, you have to delete them one by one.

There is nothing copied between drawings.
This may be an issue with your work flow or possibly you have replaced the empty drawing template with an other version containing a bunch of blocks.
Blocks are only stored in a drawing when you create or import them.
But when you use an existing drawing with blocks, remove all entities for a clean screen, the blocks remain in the drawing, even when they are not used.

All sorted now.

Got the 2.2 version and can delete all unused blocks.  Just need to make sure I delete from historic drawings.