Re: Synchronize tables question....

On Feb 19, 2007, at 9:05 AM, Richard Huxton wrote:

> Don't forget to CC: the list
>
> Jerry LeVan wrote:
>>>> Is there an elegant way I can merge/update the two tables so that
>>>> they will contain the same information ( with no duplicates or
>>>> omissions)?
>>>
>>> It sounds like you'll want some form of replication, but whether
>>> single-master or multi-master no-one can say without more
>>> information.
>
>> I meant to say I had dblink installed :)
>> The following sequence of steps seems to work ok, the tables are
>> very small...
>
>> insert into tmpRegistrations select *
>> from dblink('select * from registrations ')
>> as (software text,
>> id text,
>> value text,
>> location text
>> )
>> select dblink_disconnect()
>> create temp table newregistrations as
>> (select * from registrations union select * from
>> tmpregistrations )
>> truncate table registrations
>> insert into registrations select * from newregistrations
>
> A couple of points:
> 1. What if a registration is updated?
> 2. What happens if you get a new registration between CREATE TEMP
> TABLE and TRUNCATE?
>
> --
> Richard Huxton
> Archonet Ltd

While a "generic" solution would be nice, I am the only one using the
DB :)
(so point 2 is unlikely).

Point 1 will require a bit of thought..., currently I would have to do
a manual scan of the (small) table after the merge.

Thanks

Jerry