Andrew Dunstan <andrew@dunslane.net> writes:
> Here are some timing tests in 1m rows of random utf8 encoded 100 char
> data. It doesn't look to me like the saving you're suggesting is worth
> the trouble.
Hmm ... not sure I believe your numbers. Using a test file of 1m lines
of 100 random latin1 characters converted to utf8 (thus, about half and
half 7-bit ASCII and 2-byte utf8 characters), I get this in SQL_ASCII
encoding:
regression=# \timing
Timing is on.
regression=# create temp table test(f1 text);
CREATE TABLE
Time: 5.047 ms
regression=# copy test from '/home/tgl/zzz1m';
COPY 1000000
Time: 4337.089 ms
and this in UTF8 encoding:
utf8=# \timing
Timing is on.
utf8=# create temp table test(f1 text);
CREATE TABLE
Time: 5.108 ms
utf8=# copy test from '/home/tgl/zzz1m';
COPY 1000000
Time: 7776.583 ms
The numbers aren't super repeatable, but it sure looks to me like the
encoding check adds at least 50% to the runtime in this example; so
doing it twice seems unpleasant.
(This is CVS HEAD, compiled without assert checking, on an x86_64
Fedora Core 6 box.)
regards, tom lane
