[postgis-users] srid on wkb

[Brent Pedersen]

hi, i'm seeing some behavior i dont understand, i'm pasting a shell
session for postgresql 8.3.7 below.
can someone explain why i'm getting the error from the first command?
the wkb has srid 4326 as does the dwr_well.geom field. and
it's in the geometry_columns table as such. i've found i can get the
desired results by wrapping the wkb in st_setsrid(), but it seems
that should be necessary. is there something i'm missing.
thanks,
-brent

SELECT dwr_well.geom AS dwr_well_geom, dwr_well.id AS dwr_well_id,
dwr_well.well_number AS dwr_well_well_number
FROM dwr_well
WHERE ST_Intersects(dwr_well.geom,
'01030000208C10000001000000050000006666666666665EC06666666666E644406666666666665EC000000000000045409A99999999595EC000000000000045409A99999999595EC06666666666E644406666666666665EC06666666666E64440'::geometry);
ERROR:  Operation on two geometries with different SRIDs
dwr=# select srid('01030000208C10000001000000050000006666666666665EC06666666666E644406666666666665EC000000000000045409A99999999595EC000000000000045409A99999999595EC06666666666E644406666666666665EC06666666666E64440'::geometry);
 srid
------
 4236
(1 row)

dwr=# select distinct(srid(geom)) from dwr_well;
 srid
------
 4326
(1 row)

dwr=# select postgis_full_version();
                               postgis_full_version
----------------------------------------------------------------------------------
 POSTGIS="1.3.3" GEOS="3.1.1-CAPI-1.6.0" PROJ="Rel. 4.6.0, 21 Dec
2007" USE_STATS
(1 row)

######################
# and the working query requires explicitly setting the srid:

dwr=# SELECT dwr_well.geom AS dwr_well_geom, dwr_well.id AS
dwr_well_id, dwr_well.well_number AS dwr_well_well_number
FROM dwr_well
WHERE ST_Intersects(dwr_well.geom,
ST_SetSRID('01030000208C10000001000000050000006666666666665EC06666666666E644406666666666665EC000000000000045409A99999999595EC000000000000045409A99999999595EC06666666666E644406666666666665EC06666666666E64440'::geometry,
4326));
[ ... expected results ... ]