[postgis-users] ST_Boundary of some linestrings

[lisek lichu]

Hello,

I hane in my database 6 linestrings and I want to get the boundary rectangle
from them (not from each of them)

If i use:
select AsText(ST_Boundary(the_geom)) from segments;

i get

MULTIPOINT(-8.593025208 41.180818082,-8.594827652 41.187632944)
MULTIPOINT(-8.594827652 41.187632944,-8.591823578 41.193090782)
MULTIPOINT(-8.591823578 41.193090782,-8.611950874 41.190119708)
MULTIPOINT(-8.611950874 41.190119708,-8.613796234 41.179203081)
MULTIPOINT(-8.613796234 41.179203081,-8.602809906 41.180559684)
MULTIPOINT(-8.602809906 41.180559684,-8.593025208 41.180818082)


but i need one big Boundary. (should I group them by some atribute or there
is some siplier way to do that?)

Simon
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