CREATE TABLE myschema.mytable(
    fid serial NOT NULL,
    the_geom geometry(Point,4326),
    ele double precision,
    "time" timestamp with time zone,
    CONSTRAINT activities_pk PRIMARY KEY (fid)
);

@echo off
for %%I in (Tracks*.gpx*) do (
    echo Importing gpx file %%~nxI to myscheme.mytable PostGIS table...
    ogr2ogr -append -update -f PostgreSQL PG:"dbname='db' user='me' password='pw'" Tracks/%%~nxI -nln myscheme.mytable -sql "SELECT ele, time FROM track_points"
)