On Thu, Jul 9, 2020 at 8:18 AM Ajin Cherian <itsa...@gmail.com> wrote:
>
> On Thu, Jul 9, 2020 at 12:28 PM Amit Kapila <amit.kapil...@gmail.com> wrote:
>>
>> On Wed, Jul 8, 2020 at 7:31 PM Ajin Cherian <itsa...@gmail.com> wrote:
>>
>> Thanks for showing the interest in patch. How have you ensured that
>> streaming is happening? I don't think the proposed patch can ensure
>> it for every case because we also rely on logical_decoding_work_mem to
>> decide whether to stream/spill, see ReorderBufferCheckMemoryLimit. I
>> think with your patch it will allow streaming for cases where we have
>> large amount of WAL to decode.
>>
>
> Maybe I missed something but I looked at ReorderBufferCheckMemoryLimit, even
> there it checks the same function ReorderBufferCanStream () and decides
> whether to stream or spill. Did I miss something?
>
> while (rb->size >= logical_decoding_work_mem * 1024L)
> {
There is a check before above loop:
ReorderBufferCheckMemoryLimit(ReorderBuffer *rb)
{
ReorderBufferTXN *txn;
/* bail out if we haven't exceeded the memory limit */
if (rb->size < logical_decoding_work_mem * 1024L)
return;
This will prevent the streaming/spill to occur.
--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com
