[postgis-users] Problems with geometry's after "translate"

[Antonio Grassi]

Hello. I've come across a strange situation. It would be very helpfull if
someone out there could give me an idea of what's going on. Here is a
sequence of SQL commands issued directly through 'psql' to the Postgres
server.

1) INSERT INTO table(gid,the_geom)
VALUES(1,geometryFromText('LINESTRING(583945 6137700, 583945 6137690)',-1));

2) SELECT gid,asText(the_geom) FROM table WHERE the_geom &&
geometryFromText('POLYGON((583943 6137697, 583947 6137697, 583947 6137693,
583943 6137693, 583943 6137697))',-1);

This works as expected, and the geometry I've just created in step 1 is
listed in the results.

gid |                  astext
----+-------------------------------------------
1    | LINESTRING(583945 6137700,583945 6137690)


3) UPDATE table SET the_geom = translate(the_geom, 10, 0, 0) WHERE gid = 1;

4) SELECT gid,asText(the_geom) FROM table WHERE gid = 1;

gid |                  astext
----+-------------------------------------------
1    | LINESTRING(583955 6137700,583955 6137690)

Well, finally, I try to repeat step 2 with a new polygon to again select
that record.

5) SELECT gid,asText(the_geom) FROM table WHERE the_geom &&
geometryFromText('POLYGON((583953 6137697, 583957 6137697, 583957 6137693,
583953 6137693, 583953 6137697))',-1);

gid | astext
----+--------
(0 rows)


If there isn't something I'm understanding bad, the final step should have
retorned me the record created in step 1 and moved in step 3. I've tried
this with different geometrys, and it's the same. After using 'translate'
over the geometry, it's not accessible anymore using the '&&' operator. It
doesn't work neither if using 'intersects' instead of '&&'.

I'm using postgres 8.1.4 and postgis 1.1.2. I've using postgres+postgis for
a pair of years, and this is the first time I've seen this occur.

Well, thanks very much,
Antonio Grassi
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