[mapserver-users] WMS TIME parameter slow

[Paul Ramsey]

Firstly, 2 seconds is not fast, so you have another performance troll
beyond this one.

Secondly, it's impossible to know what's going on inside the database
without seeing the actual SQL being generated. Turn on statement
loggging in PgSQL and extract the SQL that is being run against the
database. Then you can put that into PgAdmin or psql and get EXPLAIN
ANALYZE results which will tell you why there's a problem, hopefully.

P.

On Wed, Mar 10, 2010 at 7:22 AM, Heiko Schröter
<schroete at iup.physik.uni-bremen.de> wrote:
> 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
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