[postgis-users] Small speed comparison

[Markus Schaber]

Hi,

Markus Schaber schrieb:

Now the next round, after the newest changes, using a CVS checkout from
just five minutes ago. As always, take it with a grain of salt, as the
test environment is not 100% clean.

>>lwgeom=# select geom from adminbndy1;
>>Zeit: 8629,822 ms
>>Zeit: 6401,693 ms
> Zeit: 10556,032 ms
> Zeit: 6301,014 ms
> Zeit: 5809,858 ms

Zeit: 7291,142 ms
Zeit: 5710,035 ms
Zeit: 5704,322 ms

>>lwgeom=# select asBinary(geom) from adminbndy1;
>>Zeit: 11648,607 ms
>>Zeit: 7845,229 ms
> Zeit: 7604,296 ms
> Zeit: 7465,358 ms
> Zeit: 8062,700 ms

Zeit: 7703,023 ms
Zeit: 7334,603 ms
Zeit: 7416,862 ms

>>lwgeom=# select asEWKB(geom) from adminbndy1;
>>Zeit: 7824,009 ms
>>Zeit: 7308,423 ms
> Zeit: 7191,243 ms
> Zeit: 7342,762 ms
> Zeit: 7214,146 ms

Zeit: 7179,969 ms
Zeit: 7145,012 ms
Zeit: 8065,111 ms

>>lwgeom=# select asText(geom) from adminbndy1;
>>Zeit: 33655,132 ms
>>Zeit: 33154,569 ms
> Zeit: 32816,896 ms
> Zeit: 32792,680 ms
> Zeit: 32645,417 ms

Zeit: 34633,596 ms
Zeit: 34569,356 ms
Zeit: 35005,842 ms
Zeit: 33080,449 ms
Zeit: 34586,682 ms

>>lwgeom=# select asEWKT(geom) from adminbndy1;
>>Zeit: 34402,441 ms
> Zeit: 37156,399 ms
> Zeit: 35210,384 ms
> Zeit: 33757,256 ms

Zeit: 33745,257 ms
Zeit: 33564,830 ms
Zeit: 32207,939 ms

>>lwgeom=# select asEWKB(geom)::bytea from adminbndy1;
>>Zeit: 7444,995 ms
> Zeit: 8681,531 ms
> Zeit: 7225,146 ms
> Zeit: 7230,526 ms
Zeit: 8328,522 ms
Zeit: 7241,970 ms
Zeit: 8701,952 ms
Zeit: 7133,000 ms


It seems that there is still no significant change in speed, except
possibly a small slowdown in asText(). But this may still be due to
uncertainities in my test environment. (I do not have a 100% clean spare
machine for the tests, they have to run on my developer machine which
has some other apps idling around...)

But while comparing those results, I found some odd thing (that was
present before the current changes, too): I wonder why asEWKB and
asBinary both are noticably slower than rendering canonical text
(hexEWKB), though.

Markus

-- 
markus schaber | dipl. informatiker
logi-track ag | rennweg 14-16 | ch 8001 zürich
phone +41-43-888 62 52 | fax +41-43-888 62 53
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