Re: How do I bulk insert to a table without affecting read performance on that table?

Scott Marlowe-2 wrote:
>
> On Jan 25, 2008 5:27 PM, growse <nabble(at)growse(dot)com> wrote:
>>
>> Hi,
>>
>> I've got a pg database, and a batch process that generates some metadata
>> to
>> be inserted into one of the tables. Every 15 minutes or so, the batch
>> script
>> re-calculates the meta data (600,000 rows), dumps it to file, and then
>> does
>> a TRUNCATE table followed by a COPY to import that file into the table.
>>
>> The problem is, that whilst this process is happening, other queries
>> against
>> this table time out. I've tried to copy into a temp table before doing an
>> "INSERT INTO table (SELECT * FROM temp)", but the second statement still
>> takes a lot of time and causes a loss of performance.
>
> Can you import to another table then
>
> begin;
> alter table realtable rename to garbage;
> alter table loadtable rename to realtable;
> commit;
>
> ?
>
>>
>> So, what's the best way to import my metadata without it affecting the
>> performance of other queries?
>>
>> Thanks,
>>
>> Andrew
>> --
>> View this message in context:
>> http://www.nabble.com/How-do-I-bulk-insert-to-a-table-without-affecting-read-performance-on-that-table--tp15099164p15099164.html
>> Sent from the PostgreSQL - performance mailing list archive at
>> Nabble.com.
>>
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 5: don't forget to increase your free space map settings
>>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings
>
>

This is a possibility. My question on this is that would an ALTER TABLE real
RENAME TO garbage be faster than a DROP TABLE real?
--
View this message in context: http://www.nabble.com/How-do-I-bulk-insert-to-a-table-without-affecting-read-performance-on-that-table--tp15099164p15107074.html
Sent from the PostgreSQL - performance mailing list archive at Nabble.com.