On 28.02.2024 13:07, jian he wrote:
On Wed, Feb 28, 2024 at 12:19 PM Andrei Lepikhov
<a.lepik...@postgrespro.ru> wrote:
On 26/2/2024 11:10, Alena Rybakina wrote:
On 24.02.2024 14:28, jian he wrote:
Hi.
I wrote the first draft patch of the documentation.
it's under the section: Planner Method Configuration
(runtime-config-query.html)
but this feature's main meat is in src/backend/parser/parse_expr.c
so it may be slightly inconsistent, as mentioned by others.
You can further furnish it.
Thank you for your work. I found a few spelling mistakes - I fixed this
and added some information about generating a partial index plan. I
attached it.
Thanks Jian and Alena,
It is a good start for the documentation. But I think the runtime-config
section needs only a condensed description of a feature underlying the
GUC. The explanations in this section look a bit awkward.
Having looked through the documentation for a better place for a
detailed explanation, I found array.sgml as a candidate. Also, we have
the parser's short overview section. I'm unsure about the best place but
it is better when the server config section.
doc/src/sgml/array.sgml corresponds to
https://www.postgresql.org/docs/current/arrays.html.
this GUC is related to parser|optimzier.
adding a GUC to array.sgml seems strange. (I think).
I suggest describing our feature in array.sgml and mentioning a GUC there.
We can describe a GUC in config.sgml.
2. We should describe the second part of the feature, where the
optimiser can split an array to fit the optimal BitmapOr scan path.
we can add a sentence explaining that:
it may not do the expression transformation when the original
expression can be utilized by index mechanism.
I am not sure how to rephrase it.
Maybe like that:
It also considers the way to generate a path using BitmapScan indexes,
converting the transformed expression into expressions separated by "OR"
operations, and if it turns out to be the best and finally selects the
best one.
--
Regards,
Alena Rybakina
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
