Re: Processing very large TEXT columns (300MB+) using C/libpq

All I am am doing is iterating through the characters so I know it isn't my
code.

--cnemelka

On Fri, Oct 20, 2017 at 9:14 AM, Cory Nemelka <cnemelka(at)gmail(dot)com> wrote:

> Yes, but I should be able to read them much faster. The psql client can
> display an 11MB column in a little over a minute, while in C using libpg
> library, it takes over an hour.
>
> Anyone have any experience with the same issue that can help me resolve?
>
> --cnemelka
>
> On Thu, Oct 19, 2017 at 5:20 PM, Aldo Sarmiento <aldo(at)bigpurpledot(dot)com>
> wrote:
>
>> I believe large columns get put into a TOAST table. Max page size is 8k.
>> So you'll have lots of pages per row that need to be joined with a size
>> like that: https://www.postgresql.org/docs/9.5/static/storage-toast.html
>>
>> *Aldo Sarmiento*
>> President & CTO
>>
>>
>>
>> 8687 Research Dr
>> <https://maps.google.com/?q=8687+Research+Dr,+Irvine,+CA+92618&entry=gmail&source=g>,
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>> <https://maps.google.com/?q=8687+Research+Dr,+Irvine,+CA+92618&entry=gmail&source=g>
>> *O*: (949) 223-0900 - *F: *(949) 727-4265
>> aldo(at)bigpurpledot(dot)com | www.bigpurpledot.com
>>
>> On Thu, Oct 19, 2017 at 2:03 PM, Cory Nemelka <cnemelka(at)gmail(dot)com> wrote:
>>
>>> I have getting very poor performance using libpq to process very large
>>> TEXT columns (300MB+). I suspect it is IO related but can't be sure.
>>>
>>> Anyone had experience with same issue that can help me resolve?
>>>
>>> --cnemelka
>>>
>>
>>
>