[postgis-devel] WKTRaster: RFC1: serialized form

[strk]

On Thu, Jan 29, 2009 at 04:35:06PM +0100, strk wrote:
> On Thu, Jan 29, 2009 at 09:17:49AM -0500, Pierre Racine wrote:
> > >Also added example total sizes of single band on-disk rasters.
> > >A 64x64 16bit band won't fit in a default potgresql page size,
> > >an 8bit band of that dimension would.
> > 
> > Nice work. I always wondered what were the implications of working with
> > data bigger than the page size.
> 
> Data that fits in a page size won't need to be compressed
> or stored in a separate table (the TOAST table), so it more
> quickly gets loaded into memory.

Since we're on the matter, last thing I'd like we all agree
on is the size (in bits) of values for pixeltype in (PT_1BB,
PT_2BUI, PT_4BUI).

These could be encoded as 1bit, 2bit, 4bit respectively,
saving space on disk, but requiring more CPU cycles to read.
Or could be encoded all as 8bit, making things simpler to
manage but saving nothing.

Beside, it seems GDAL doesn't support pixel types with length < 8bit.

--strk;

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