Re: How can I manually alter the statistics for a column?

Douglas Alan <darkwater42(at)gmail(dot)com> writes:
> Hey, while I have you on the line, might you be so kind as to explain why
> this query is so slow? Shouldn't it just fetch the first row in the table?
>
> explain analyze select * from maindb_astobject limit 1;

Yeah ...

>> QUERY
>> PLAN
>>
>> ------------------------------------------------------------------------------------------------------------------------------------
>> Limit (cost=0.00..0.04 rows=1 width=78) (actual time=8091.962..8091.965
>> rows=1 loops=1)
>> -> Seq Scan on maindb_astobject (cost=0.00..3358190.12 rows=75426912
>> width=78) (actual time=8091.955..8091.955 rows=1 loops=1)
>> Total runtime: 8092.040 ms
>> (3 rows)

Ouch.

I'm betting that this table is horrendously bloated and the seqscan is
picking through many thousands of dead rows before it finds the first
live one. Cue standard questions about your vacuuming habits ...

regards, tom lane