explain-analyze.info | query-plan-1235

Summary

Time		Node
Node (ms)	Percent	Node
0.011	100.00%	¶	`Aggregate (cost=20.25..20.26 rows=1 width=0) (actual time=0.011..0.011 rows=1 loops=1)`
0.002	18.18%	¶	`-> Seq Scan on table1 (cost=0.0..18.2 rows=820 width=0) (actual time=0.002..0.002 rows=0 loops=1)`

Highlighted rows indicate a disparity between the number of rows estimated and actually returned. You may want to run ANALYZE to update the server's statistics.
For more information on using EXPLAIN and interpreting its output, see the Postgres documentation, in particular the EXPLAIN and ANALYZE references pages, and Using Explain.