Re: exclusive locking on SELECT ?

On 12-Jan-07, at 9:14 AM, James Neff wrote:

> Dave Cramer wrote:
>>
>> On 11-Jan-07, at 4:47 PM, James Neff wrote:
>>
>>> Greetings,
>>>
>>> I have 3 clients trying to do a select on the same table
>>> (different rows).  pgAdmin III Server Status shows the queries
>>> and has as mode "Exclusive Lock" for all three.
>> Are you doing select for update ? If so why so many rows ?
>>
>>
>
> No updates, just a select.  Is there a way (in Java) to only select
> one row at a time from a resultset, and is this a good idea?  The
> clients are processing rows from this one table in 2000 record
> chunks.  There are about 9 million rows total to process.

you can setFetchSize to allow the driver to fetch fewer at a time.
>
>
>>>
>>> How would I go about diagnosing this situation, and how do I fix it?
>>
>> Have you tuned the server ?
>
> I'm doing a search now on "tuning postgres".  Do you have any
> suggested links that might pertain to my particular situation?
Well, I'd have to see exactly what the machine was doing, how big it
is, etc.

Dave
>
> Thanks again,
> James
>