Hi!
At 15:50 17.08.00 +0100, you wrote:
> Isn't easier to reduce the table every day and make a daily vacuum which
only
> lasts a few seconds?
Well, sounds simple, but I still have some headaches here:
a) Full Data must be available a month or so (OK, that could be done by
COPYing
the insert table into an offline table)
b) I would prefer near-to zero downtime - else the client (a near real-time
app)
would have to do things like determine server status, buffering etc. pp., und
would get considerably more complex.
Joerg Hessdoerfer wrote:
>> Hi!
>>
>> I have an application, where I have to insert data into a table at several
>> rows per second, 24 hours a day, 365 days a year.
>>
>> After some period (a week, maybe a month) the data will be reducted to some
>> degree and deleted from the table.
>>
>> As far as I understood, I would have to use VACUUM to really free the table
>> from deleted rows - but VACUUM (esp. on a table with several million rows)
>> takes some time and prevents me from inserting new data.
>>
>> Now, I thought I could just rename the table, inserting into a temp
table, and
>> switch the tables back after VACUUMing. Ideally, this should work unnoticed
>> (and thus without prog. effort) on the client (inserter) side.
>>
>> Question: would it work to use a transaction to perform the rename?
>>
>> i.e.: continuous insert into table 'main' from client.
>>
>> From somewhere else, execute:
>>
>> begin;
>> alter table main rename to vac_main;
>> create table main (...);
>> end;
>>
>> would the inserter notice this? Read: would ALL inserts AT ANY TIME
succeed?
>>
>> I know, I could simulate such functionality in the client (inserter).
But it
>> seems more elegant this way...
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