Database Reference
In-Depth Information
Comparingthetextof srtext tothePRISMraster'smetadataspatialattributes,we
find that the raster is in WGS72 (SRID 4322).
You can load the PRISM rasters into the chap5.prism table with raster2pgsql .
> raster2pgsql -s 4322 -t 100x100 -F -I -C -Y
C:\postgis_cookbook\data\chap5\PRISM\us_tmin_2012.*.asc
chap5.prism | psql -d postgis_cookbook
The raster2pgsql command is called with the following flags:
-s : This flag assignsSRID 4322 to the imported rasters.
-t :Thisflagdenotesthetilesize.Itchunkstheimportedrastersintosmaller
andmoremanageablepieces;eachrecordaddedtothetablewillbeatmost
100 x 100 pixels.
-F : This flag adds a column to the table and fills it with the raster's filename.
-I : This flag creates a GIST spatial index on the table's raster column.
-C :Thisflagappliesthestandardsetofconstraintsonthetable.Thestand-
ardsetofconstraintsincludeschecksfordimension,scale,skew,upper-left
coordinate, and SRID.
-Y : This flag instructs raster2pgsql to use COPY statements instead of
INSERT statements. COPY is typically faster than INSERT .
Thereisareasonwhywepassed -F to raster2pgsql .Ifyoulookatthefilenames
ofthePRISMrasters,you'llnotetheyearandmonth.So,let'sconvertthevaluein
the filename column to a date in the table.
ALTER TABLE chap5.prism ADD COLUMN month_year
DATE;
UPDATE chap5.prism SET month_year = (
split_part(split_part(filename, ''.'',
1), ''_'', 3) || ''-'' ||
split_part(filename, ''.'', 2) || ''-01''
)::date;
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