Re: query hangs

On 10 June 2010 18:47, AI Rumman <rummandba(at)gmail(dot)com> wrote:

> I am using Postgresql 8.1 and did not find FETCH_COUNT
>
>
Oh ok. Looks like FETCH_COUNT was introduced in 8.2

> On Thu, Jun 10, 2010 at 6:55 PM, Amit Khandekar <
> amit(dot)khandekar(at)enterprisedb(dot)com> wrote:
>
>>
>>
>> On 10 June 2010 18:05, AI Rumman <rummandba(at)gmail(dot)com> wrote:
>>
>>> Could you please give me the link for cursor- How to use it?
>>>
>>>
>>> On Thu, Jun 10, 2010 at 6:28 PM, Kevin Grittner <
>>> Kevin(dot)Grittner(at)wicourts(dot)gov> wrote:
>>>
>>>> AI Rumman wrote:
>>>>
>>>> >> Merge Left Join (cost=9500.30..101672.51 rows=2629549 width=506)
>>>>
>>>> > And the query does not return data though I have been waiting for
>>>> > 10 mins.
>>>> >
>>>> > Do you have any idea ?
>>>>
>>>> Unless you use a cursor, PostgreSQL interfaces typically don't show
>>>> any response on the client side until all rows have been received and
>>>> cached on the client side. That's estimated to be over 2.6 million
>>>> rows in this case. That can take a while.
>>>>
>>>> You might want to use a cursor....
>>>>
>>>>
>>
>> If you are using psql client, using FETCH_COUNT to a small value will
>> allow you to achieve cursor behaviour. psql starts returning batches of
>> FETCH_COUNT number of rows .
>>
>> E.g. \set FETCH_COUNT 1
>> will start fetching and displaying each row one by one.
>>
>>
>>
>>
>> -Kevin
>>>>
>>>
>>>
>>
>