Query plan - now what?

Well, now that I have the plan for my slow-running query, what do I do? Where
should I focus my attention?
Thanks.
-David

Hash Join (cost=16620.59..22331.88 rows=40133 width=266) (actual
time=118773.28..580889.01 rows=57076 loops=1)
-> Hash Join (cost=16619.49..21628.48 rows=40133 width=249) (actual
time=118771.29..535709.47 rows=57076 loops=1)
-> Hash Join (cost=16618.41..20724.39 rows=40133 width=240) (actual
time=118768.04..432327.82 rows=57076 loops=1)
-> Hash Join (cost=16617.34..19920.66 rows=40133 width=223) (actual
time=118764.67..340333.78 rows=57076 loops=l)
-> Hash Join (cost=16616.14..19217.14 rows=4Ol33 width=214) (actual
time=118761.38..258978.8l row=57076 loops=1)
-> Merge Join (cost=16615.07..18413.42 rows=40133 width=205)
(actual time=118758.74..187180.55 rows=57076 loops=i)
-> Index Scan using grf_grf_id_idx on giraffes (cost=O.O0..1115.61
rows=53874 width=8)
(actual
time=2.37..6802.38 rows=57077 loops=l)
-> Sort (cost=l66l5.07..16615.07 rows=18554 width=197) (actual
time=118755.11..120261.06 rows=59416 loops=l)
-> Hash Join (cost=8126.08..14152.54 rows=18554 width=197)
(actual time=50615.72..l09853.7l rows=16310 loops=1)
-> Hash Join (cost=8124.39..12690.30 rows=24907 width=179)
(actual time=50607.36..86868.58 rows=iSBiS loops=1)
-> Hash Join (cost=249.26..2375.23 rows=24907 width=131)
(actual time=23476.42..35107.80 rows=16310 loops=l)
-> Nested Loop (cost=248.2l..1938.31 rows=24907 width=118)
(actual time=23474.70..28155.13 rows=16310 loops=1)
-> Seq Scan on zebras (cost=0.00..l.0l rows=l width=14)
(actual time=O.64..0.72 rows=1 ioops=1)
-> Materialize (cost=1688.23..l688.23 rows=24907 width=104)
(actual time=23473.77..23834.26 rows=16310 loops=l)
-> Hash Join (cost=248.21..1688.23 rows=24907 width=lO4)
(actual time=1199.26..23059.92 rows=16310 loops=l)
-> Seq Scan on frogs (cost=0.00..755.07 rows=24907 width=83)
(actual time=0.53..4629.58 rows=25702
loops=l)
-> Hash (cost=225.57..225.57 rows=9057 width=21)
(actual time=1198.0l..1198.01 rows=0 loops=1)
-> Seq Scan on tigers (cost=0.00..225.57 rows=9057 width=21)
(actual time=0.39..892.67 rows=9927
loops=1)
-> Hash (cost=l.O4..1.-4 rows=4 width=13) (actual time=l.07..1.07
rows=0 loops=1)
-> Seq Scan on deers (cost=0.0O..1.04 rows=4 width=13)
(actual time=0.64..0.95 rows=4 loops=1)
-> Hash (cost=4955.28..4955.28 rows=91528 width=48)
(actual tlne=27O40.82..27040.82 rows=0 loops=1)
-> Seq Scan on warthogs (cost=0.00..4955.28 rows=91528 width=48)
(actual time=3.92..24031.27 rows=91528
loops=1)
-> Hash (cost=1.55..1.55 rows=55 width=18) (actual time=7.l3..7.13
rows=0 loops=1)
-> Seq Scan on monkeys (cost=0.00..l.55 rows=55 width=18)
(actual time=0.64..5.38 rows=55 loops=1)
-> Hash (cost=l.O5..1.05 rows=S width=9) (actual time=1.16..l.l6 rows=0
loops=1)
-> Seq Scan on worms (cost=0.00..1.05 rows=S width=9) (actual
time=0.65..1.00 rows=5 loops=1)
-> Hash (cost=1.16..1.16 rows=16 width=9) (actual time=l.86..1.86 rows=0
loops=1)
-> Seq Scan on lions (cost=0.00..l.16 rows=16 width=9) (actual
time=0.lO..1.36 rows=16 loops=1)
-> Hash (cost=1.06..1.06 rows=6 width=17) (actual time=1.35..1.35 rows=0
loops=1)
-> Seq Scan on dogs (cost=0.00..1.06 rows=6 width=17) (actual
time=0.65..1.16 rows=6 loops=l)
-> Hash (cost=1.07..1.07 rows=3 width=9) (actual time=1.23..1.23 rows=0
loops=1)
-> Seq Scan on parrots (cost=0.00..1.07 rows=3 width=9) (actual
time=0.69..1.13 rows=3 loops=1)
-> Hash (cost=l.08..1.08 rows=8 width=17) (actual time=0.98..0.98 rows=0
loops=1)
-> Seq Scan on rhinos (cost=0.00..1.08 rows=8 width=17) (actual
time=0.10..0.73 rows=8 loops=1)

Total runtime: 58l341.00 msec