[mapserver-users] WMS TIME parameter slow

[Heiko Schröter]

Hello,

using mapserv (5.6.1) with PostGIS (8.3) and accessing ten-thousands of geo locations in the PostGIS db results in very slow speed when using the WMS TIME parameter:
(in this example the number is about 4000 datapoints for this day, timing measurements with DEBUG OFF).

1) Very fast using FILTER, approx. 5 seconds:
....
CONNECTION "user={BF961C25A57BA226} password={C9748CA35D48D049} dbname={6B40E65B12B92106} host=localhost"
DATA "geocoord from xyz_ref using unique datum"
VALIDATION
'filter' "^datum >= '[0-9]{4}-[0-9]{2}-[0-9]{2}' and datum <= '[0-9]{4}-[0-9]{2}-[0-9]{2}'"
END
FILTER "datum >= '2007-12-10' and datum < '2007-12-11'"
....

2) Very slow using WMS TIME, approx 210 and more seconds:
(Leaving the VALIDATION/FILTER on or leaving out 'using unique datum' doesn't change a thing)
...
METADATA
"wms_timeextent" "1970-01-01/2030-12-31"
"wms_timeitem" "datum"
"wms_timedefault" "2007-12-10/2007-12-11"
"wms_title" "xyz_r"
"wms_srs" "init=epsg:-1"
END
...

The MS ERRORFILE is very noisy spilling out all datapoints when running 2). This does not happen when running 1).
Database is the same. No other changes have been made.

Why is mapserver so slow when using the WMS TIME parameter ?

It would be nice to stick to the "official" WMS configuration and not to introduce a "vendor specific" workaround.

Thanks and Regards
Heiko

# ######################################################################################################

/var/www/localhost/cgi-bin/mapserv -v
MapServer version 5.6.1 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP OUTPUT=SVG SUPPORTS=PROJ SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=ICONV SUPPORTS=WMS_SERVER SUPPORTS=WFS_SERVER SUPPORTS=WCS_SERVER INPUT=EPPL7 INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE

A complete Layer definition:

	LAYER
		EXTENT -180 -90 180 90
		CONNECTIONTYPE POSTGIS
		NAME "SACURA_REF_R"
		PROCESSING "CLOSE_CONNECTION=DEFER"
		OPACITY 60
		STATUS ON
		METADATA
#			"wms_timeextent" "1970-01-01/2030-12-31"
#			"wms_timeitem" "datum"
#			"wms_timedefault" "2007-12-10/2007-12-11"
			"wms_title" "xyz_ref_r"
			"wms_srs" "init=epsg:-1"
		END
		PROJECTION
			"init=epsg:4326"
		END
		CONNECTION "user={BF961C25A57BA226} password={C9748CA35D48D049} dbname={6B40E65B12B92106} host=localhost"
		DATA "geocoord from xyz_ref using unique datum"
 		VALIDATION
 			'filter' "^datum >= '[0-9]{4}-[0-9]{2}-[0-9]{2}' and datum <= '[0-9]{4}-[0-9]{2}-[0-9]{2}'"
 		END
 		FILTER "datum >= '2007-12-10' and datum < '2007-12-11'"

		TYPE POLYGON
		SIZEUNITS meters
		CLASS
			DEBUG OFF
			NAME "xyz_ref_class"
			STYLE
				OUTLINECOLOR 0 0 0
				COLOR [rfarbe]
			END
		END
	END # Layer