Re: Natural key woe

>
>> One other wrinkle to note. After clearing out these rows, running 'VACUUM
>> table2', 'ANALYZE table2' and 'REINDEX table table2', some queries with
>> simple sequence scans were taking a few seconds to run even though there
>> are only a thousand rows in the table. I finally found that running CLUSTER
>> on the table sorted that out, even though we're on an SSD so I would have
>> thought seeking all over the place for a seq. scan wouldn't have made that
>> much difference. It obviously does still make some.
>>
>> A VACUUM FULL table2 would have made the CLUSTER unnecesary. A normal
VACUUM only marks dead rows as free but does not shrink the table. A VACUUM
FULL removes all the free space from the table and returns it to the OS.

Eelke Klein