About Variable Sized Arrays for system calls

hi All,
Since Now system Verilog has added Variable Sized arrays,
I need to know one thing


For dynamic arrays as such

initial
begin
int a[];
$readmemb("p1.dat",a);
end


SHould the readmemb call create a new array or error out,

My questions in the more consolidated way are
$readmemb, $readmemh, $fread
1. Dynamic Arrays
a. Should they overwrite the current data and start from the end of
the existing information.
b. If a DA has not been newed , can data be written onto it.
c. If a DA has been newed for 10 bytes but we are reading more than
than that, what is the case.
d. The data or the memory file could have addresses too( indices ) ,
Should they follow the same semantics as fixed unpacked arrays.

2. Smart Queues
a. Should they overwrite the current data or add it to the end
b. What are the semantics for the start address and end address that
$readmem calls usually take as 3rd and 4th argument
c. Same as 1.d

3. Assoc Arrays
a. Should they overwrite the current data or add to it
b. What should the choice of keys for the same. Should the user send
the memory or the data file with two lines for each member data , one
with the key and the other with the value.
c. What about the readmem calls with start index and end index. Do we
allow them.