Hi, all.
Some of my clients use JOIN's with three - four clauses. Quite
frequently, I see complaints on unreasonable switch of JOIN algorithm to
Merge Join instead of Hash Join. Quick research have shown one weak
place - estimation of an average bucket size in final_cost_hashjoin (see
q2.sql
Does anyone else have an opinion on this patch? It looks promising.
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On Wed, Jun 28, 2023 at 04:53:06PM +0300, Alena Rybakina wrote:
> Hi!
>
> On 15.06.2023 11:30, Andrey Lepikhov wrote:
>
> Hi, all.
>
> Some
Hi,
On Thu, Jun 15, 2023 at 4:30 PM Andrey Lepikhov
wrote:
> Hi, all.
>
> Some of my clients use JOIN's with three - four clauses. Quite
> frequently, I see complaints on unreasonable switch of JOIN algorithm to
> Merge Join instead of Hash Join. Quick research have shown one weak
> place - esti
On Mon, Sep 11, 2023, at 11:51 AM, Andy Fan wrote:
> Hi,
>
> On Thu, Jun 15, 2023 at 4:30 PM Andrey Lepikhov
> wrote:
>> Hi, all.
>>
>> Some of my clients use JOIN's with three - four clauses. Quite
>> frequently, I see complaints on unreasonable switch of JOIN algorithm to
>> Merge Join in
Hi!
On 15.06.2023 11:30, Andrey Lepikhov wrote:
Hi, all.
Some of my clients use JOIN's with three - four clauses. Quite
frequently, I see complaints on unreasonable switch of JOIN algorithm
to Merge Join instead of Hash Join. Quick research have shown one weak
place - estimation of an averag
On 3/11/2023 23:43, Tomas Vondra wrote:
On 9/11/23 10:04, Lepikhov Andrei wrote:
* Determine bucketsize fraction and MCV frequency for the inner
* relation. We use the smallest bucketsize or MCV frequency estimated
* for any individual hashclause; this is undoubtedly conservative.
I'm sure
On 9/11/23 10:04, Lepikhov Andrei wrote:
>
>
> On Mon, Sep 11, 2023, at 11:51 AM, Andy Fan wrote:
>> Hi,
>>
>> On Thu, Jun 15, 2023 at 4:30 PM Andrey Lepikhov
>> wrote:
>>> Hi, all.
>>>
>>> Some of my clients use JOIN's with three - four clauses. Quite
>>> frequently, I see complaints on unre