[mapserver-users] performance problem with PostGIS layer

[simon mercier]

hi,
I have performance problem with my PostGIS layer in mapserver.. It's
slow... vvvery slow, when zoom in, zoom out and pan.  I'am new with
PostgreSQL, PostGIS, MapServer and realy don't know where to look for
this problem! I have a table of 392000 row of polygon with oid and GiST
index . I have a debian server with a 933 CPU and 128 of RAM...

--I have good result when retrieving data with spatial SQL query :
explain select count(*) from pclp_s where the_geom &&
GeometryFromText('BOX3D(-72.15 46.43, -72.13 46.45)'::BOX3D,-1)
Aggregate  (cost=8.94..8.94 rows=1 width=0)
  ->  Index Scan using idx_geom_pclp_s on pclp_s  (cost=0.00..8.93
rows=2 width=0)

--With the same box, (i.e. EXTENT -72.15 46.43 -72.13 46.45 in map
file)  it take 80 sec for display image in IE with MapServer...

--A look on status server indicate postmaster take all CPU:
 14:51:39 up 1 day, 23:31,  5 users,  load average: 0.69, 0.29, 0.10
60 processes: 56 sleeping, 4 running, 0 zombie, 0 stopped
CPU states:  49.1% user,  44.7% system,   0.0% nice,   6.2% idle
Mem:    126060K total,   122584K used,     3476K free,     1380K buffers

Swap:   248968K total,    19516K used,   229452K free,    71440K cached

  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
 7255 postgres  18   0  3920 3920  3236 R    85.6  3.1   0:13 postmaster

 7254 www-data   9   0  3080 3080  1876 S     0.0  2.4   0:00 mapserv
 7253 root      11   0   992  992   776 R     0.3  0.7   0:00 top

It is a server harware problem or a soft setup problem? There is
someting to do?

regard

--
Simon Mercier
Technicien en Géomatique
Direction des technologies de l'information
La Financière agricole du Quebec
5825, rue Saint-Georges
Lévis, Québec,Canada G6V 4L2
http://www.fadq.qc.ca/