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  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
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> 

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?
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