Gregory Stark wrote:
"Jonah H. Harris" <[EMAIL PROTECTED]> writes:

This proposed design is overcomplicated and a waste of space.  I mean,
we reduce storage overhead using phantom command id and variable
varlena, but let's just fill it up again with unnecessary junk bytes.

We reduced storage overhead using phantom command id by 8 bytes *per tuple*. I
hardly think 8 bytes per page is much of a concern. You're already losing an
average of 1/2 a tuple per page to rounding and that's a minimum of 16 bytes
for the narrowest of tuples.

That seems pretty unlikely. CRC checks are expensive cpu-wise, we're already
suffering a copy due to our use of read/write the difference between
read/write of 8192 bytes and readv/writev of 511b*16+1*6 is going to be
non-zero but very small. Thousands of times quicker than the CRC.
Prove it.

We've already seen wal CRC checking show up at the top of profiles.

yeah - on fast boxes (diskio wise) wal-crc checking is nearly always on the very top of wal-intensive workloads.


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