BUG #7591: Large query string has limit

The following bug has been logged on the website:

Bug reference: 7591
Logged by: Pat King
Email address: pking@nrcan.gc.ca
PostgreSQL version: 9.1.3
Operating system: RedHat Linux 6.2
Description:

Hi :

I am dealing with the open source program called "Geonetwork". It is passing
the following query to postgres/postgis :

SELECT "fid", asText("the_geom") FROM "public"."spatialindex" WHERE ("fid" =
'10') OR ("fid" = '100') OR ("fid" = '1000') OR ("fid" = '10001') OR ("fid"
= '10005') ..........

Unfortunately, the query has > 50,000 OR clauses, and the query hangs.

I tried the query for < 50,000 OR clauses with success.

The spatialindex table is :

geonetwork=# \d spatialindex
Table "public.spatialindex"
Column | Type | Modifiers
----------+------------------------+-----------
fid | integer | not null
id | character varying(250) |
the_geom | geometry |
Indexes:
"spatialindex_pkey" PRIMARY KEY, btree (fid)
"spatialindexndx1" btree (id)
"spatialindexndx2" gist (the_geom)
Check constraints:
"enforce_dims_the_geom" CHECK (st_ndims(the_geom) = 2)
"enforce_geotype_the_geom" CHECK (geometrytype(the_geom) =
'MULTIPOLYGON'::text OR the_geom IS NULL)
"enforce_srid_the_geom" CHECK (st_srid(the_geom) = 4326)