Why does postgres not take into account my index on a bigint column ?

Hi,

I noticed that postgres does not take into account index on BIGINT column when the value specified in the WHERE condition is not quoted.
My problem is that I use third part programs that automatically generate many select queries where numeric values are not surrounded with quotes.

So does anybody know a way to force postgres to consider using indices on bigint columns even when the value in a where cond is not surrounded by quotes ?

Thanks

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For instance, in the following 'header' table I have a bigint column 'objectId'. Here is what I get when running the explain command:

idns_dev=# explain select * from header where objectid = '47866';

NOTICE: QUERY PLAN:
Index Scan using header_pkey on header (cost=0.00..3.92 rows=1 width=552)
EXPLAIN

idns_dev=# explain select * from header where objectid = 47866;

NOTICE: QUERY PLAN:
Seq Scan on header (cost=0.00..2246.50 rows=1 width=552)
EXPLAIN

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