Index usage on date feild , differences in '>' and '>=' and between

Hi ,

I am trying to improve a  query to use  existing indexes but facing diffculty.


Looks like 'between' amd '>=' are not using indexes althoug > and < does.
all my application code uses between and i am sure it use to work fine
at one point of time.


regds
mallah.

SQL TRANSCRIPT:
======================================================================================

tradein_clients=> explain  select   list_id from eyp_rfi a where  generated >  '2002-08-13' and generated <
'2002-09-19'  ; 
NOTICE:  QUERY PLAN:

Index Scan using eyp_rfi_date on eyp_rfi a  (cost=0.00..15796.97 rows=4150 width=4)

EXPLAIN
tradein_clients=> explain  select   list_id from eyp_rfi a where  generated >=  '2002-08-13' and generated <
'2002-09-19'  ; 
NOTICE:  QUERY PLAN:

Seq Scan on eyp_rfi a  (cost=0.00..17923.81 rows=5061 width=4)

EXPLAIN
tradein_clients=> explain  select   list_id from eyp_rfi a where  generated >=  '2002-08-13' and generated <=
'2002-09-19'  ; 
NOTICE:  QUERY PLAN:

Seq Scan on eyp_rfi a  (cost=0.00..17923.81 rows=5061 width=4)

EXPLAIN
tradein_clients=> explain  select   list_id from eyp_rfi a where  generated between '2002-08-13' and  '2002-09-19'   ;
NOTICE:  QUERY PLAN:

Seq Scan on eyp_rfi a  (cost=0.00..17923.81 rows=5061 width=4)

EXPLAIN
tradein_clients=>
======================================================================================




--
Rajesh Kumar Mallah,
Project Manager (Development)
Infocom Network Limited, New Delhi
phone: +91(11)6152172 (221) (L) ,9811255597 (M)

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