I think this would be a real usability boost
it would be useful, I agree… specially because I was used to it in Excel… in LibreOffice I had to invest some time to change that habbit 
I was use Lotus-123 since 1987, Lotus Symphony since 1991, Change to Lotus 123 for Windows since 1996, MS Excel since version 2000, and now use both Excel and LO 4. I know that new feature must be a great advantage.
From version 5.0., It is possible to specify references to entire columns or rows using the A:A or 1:1 notation instead of A1:A1048576 or A1:AMJ1.
It doesn’t work for conditional formatting,though. It just becomes A1:A1048576 and then when you swap rows, the conditional formatting is broken. Every. Time.
As longs as you have a fairly recent version (roughly newer than 4.0.4.2) you can set the formula settings to “Excel A1” (tools>options>formula>calc>formula>formula syntax) to get this support!
Then =sum(A:A) will work!
And if possible check for already existing similar requests beforehand… see other answers; anyway, this is now implemented for 5.0
This enhancement request is already specified in fdo#44419.
You can always write formula: =SUM(A1:A1048576) if you need. But it would be interesting to know why someone needs such a formula. I have been using spreadsheets for ages but have never needed such a formula…
You can always write formula: =SUM(A1:A1048576) if you need. But it would be interesting to know why someone needs such a formula. I have been using spreadsheets for ages but have never needed such a formula…
you don write that formula, but select entire column 
that is so good about it… you just write =sum( and then select entire column from column headers… I find it very useful.
It allows for a more business orientated logic rather than programming logic.
=sum(a:a) makes a hell of a lot more sense in terms of “just give me a total for the column”. When making a spreadsheet, you often use this with portability in mind. Remember, spreadsheets are a business tool…
The reason I use this is because the correct replacement is =SUM(A$1:A$1048576). Dollar signs are not necessary on a full column reference.