Martijn van Oosterhout kleptog@svana.org writes:
- Test a way of storing tuples with less overhead than a HeapTuple
header. If you could do it for in-memory sorts, that'd mean you could
fit more tuples in memory before spilling to disk. Given the
compression in that case is extremely cheap,
On Tue, 2006-05-23 at 14:27 -0400, Tom Lane wrote:
Martijn van Oosterhout kleptog@svana.org writes:
- Test a way of storing tuples with less overhead than a HeapTuple
header. If you could do it for in-memory sorts, that'd mean you could
fit more tuples in memory before spilling to disk.
I'm going to be offline for a few days but there are some things I've
tested in the meantime.
Once the compression level drops below 4-to-1 the overhead of zlib
becomes overwhelming compared to the savings. I'm not sure how common
that is, I basically filled a table for random data to get it that
BTW, the test I ran this weekend ended up filling the disk, so I wasn't
able to get results. I hope to have results for a compressed sort that's
still larger than memory in the morning. Unfortunately I'm doing all
this on a machine I use for other things, so it's hard to do testing and
other
Martijn van Oosterhout kleptog@svana.org writes:
I implemented a basic implementation using pg_lzcompress. It appears
that pg_lzcompress is very, very slow. I was afraid that I'd made an
infinite loop, but it was just really slow. Mind you, the overhead of
each call might have been the
