Spatial Databases - Desktop GIS: Mapping the Planet with Open Source Tools - page 95

$ psql gis_data
Welcome to psql 8.2.4, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms

\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit

gis_data= # \d parklands
Table "public.parklands"
Column | Type | Modifiers
----------+-----------------------+-----------
id | integer | not null
name | character varying(10) |
the_geom | geometry |

Indexes:
"parklands_pkey" PRIMARY KEY, btree (id)
"sidx_parklands" gist (the_geom)
Check constraints:
"enforce_dims_the_geom" CHECK (ndims(the_geom) = 2)
"enforce_geotype_the_geom" CHECK (geometrytype(the_geom) =
'POLYGON'::text OR the_geom IS NULL)
"enforce_srid_the_geom" CHECK (srid(the_geom) = 4326)

We use the \d command to list the properties of the parklands table.
Notice under the indexes heading there is a primary key on the id field
and, under that, a GiST index on the geometry column the_geom . If you
don't see an entry for a GiST index in the list, you should create one
for your table. To create a GiST index for your table, use the following
SQL:

CREATE INDEX sidx_parklands on parklands USING GIST (the_geom GIST_GEOMETRY_OPS);

If you import shapefiles using SPIT, a GiST index will not be created.
Using shp2pgsql allows you specify the creation of a GiST index during
the import of the shapefile. See Section 11.4 , Importing Shapefiles, on
page 203 for an example.

Loading PostGIS Data
There are a number of ways to load data into a PostGIS-enabled data-
base. In Chapter 11 , Using Command-Line Tools, on page 174 , you will
see how to load data using both the OGR and PostGIS command-line
utilities. For now we'll look at two other methods for loading data: SQL
and QGIS.