Giuseppe Bilotta wrote:
Sunday, December 4, 2005 Ian Lynch wrote:
That depends on the size of the file. In fact compression can actually
speed up opening a file. Disc to RAM is slow but processes in RAM are
fast so loading a compressed file from disc to RAM and then
decompressing entirely in solid state could actually be faster than just
loading an uncompressed file from a disc to RAM. There are several
factors that could each be significant or insignificant.
That's why you need to do the sums and not just speculate.
You need to do more than the sum :) If the original file
doesn't fit in RAM, it's faster to mmap it to/from disk in
uncomprssed form than to load the compressed version and
then going back and forth between memory and disk because of
swap usage.
The truth is probably that there is no general truth about
what's faster and what's not.
Of course, the point remains that OOo has plenty of room for
optimization :)
Bingo!! By jove he's got it! That's what I've been trying to get across
unsuccessfully. The size of the tags *does* make a difference if it
makes the file so big that it won't fit into RAM anymore. That's what my
disc thrashing comment was meant to convey, but I guess folks didn't
make the connection.
Remember, this was a big file. 63,260 rows by 7 columns. That's 442,820
instances of the 80 bytes of "taggage" surrounding each cell (35 MB,
total) plus the tags at the start of each row (times 63,260) plus all
the header information. Apparently with 256 MB RAM I simply ran out of
room loading the ods which didn't happen with the csv (or the xls).
Honestly, I haven't tried loading it since I stuck another 512 MB in
this thing. I'm sure that would make a big difference.
--
Rod
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
