On 6/2/05, K C Lau <[EMAIL PROTECTED]> wrote: ... > > select DISTINCT ON (PlayerID) PlayerID,AtDate from Player where > PlayerID='22220' order by PlayerID desc, AtDate desc; > The Player table has primary key (PlayerID, AtDate) representing data over > time and the query gets the latest data for a player. > > ... > esdt=> explain analyze select DISTINCT ON (PlayerID) PlayerID,AtDate from > Player > where PlayerID='22220' order by PlayerID desc, AtDate desc; > Unique (cost=0.00..2507.66 rows=1 width=23) (actual time=0.000..187.000 > rows=1 loops=1) > -> Index Scan Backward using pk_player on player (cost=0.00..2505.55 > rows=8 > 43 width=23) (actual time=0.000..187.000 rows=1227 loops=1) > Index Cond: ((playerid)::text = '22220'::text) > Total runtime: 187.000 ms >
Is PlayerID an integer datatype or a text datatype. It seems like PlayerID should be an integer data type, but postgres treats PlayerID as a text data type. This is because the value '22220' is quoted in your query. Also, the explain analyze output shows "Index Cond: ((playerid)::text = '22220'::text". George Essig ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match