[pgpool-general: 8298] Re: Timestamp cast not cached
Tatsuo Ishii
ishii at sraoss.co.jp
Tue Jul 5 06:37:58 JST 2022
provolatile column of pg_proc has been already considered in the
existing code. See the code block started with "if (IsA(node,
FuncCall))" in non_immutable_function_call_walker().
> I thought the provolatile should be considered. Because I saw in the block
> code you disable today in order to fix the issue, a method which called
> isSystemType.
>
> That function has condition which compare some value with the pg_catalog so
> I thought it’s could be related.
>
> Thanks,
>
> Avi
>
> On Mon, 4 Jul 2022 at 15:34 Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
>
>> provolatile column of pg_proc is not involved here. After PostgreSQL
>> (Pgpool-II) parses "Select ‘2022-02-18
>> 07:00:00.006547+02’::timestamptz;" it produces a parse tree like
>> below. As you can see, there's no function call in it. It is
>> essentially a "type cast" node with type name "timestamptz".
>>
>> I think what Pgpool-II needs to do here is, finding a type cast node
>> with its data type "timestamptz" (probably "timetz" should be
>> considered as well). If it finds, mark the SQL as "we should not cache
>> it".
>>
>> test=# Select '2022-02-18 07:00:00.006547+02'::timestamptz;
>> 2022-07-04 20:16:13.571 JST [896725] LOG: raw parse tree:
>> 2022-07-04 20:16:13.571 JST [896725] DETAIL: (
>> {RAWSTMT
>> :stmt
>> {SELECT
>> :distinctClause <>
>> :intoClause <>
>> :targetList (
>> {RESTARGET
>> :name <>
>> :indirection <>
>> :val
>> {TYPECAST
>> :arg
>> {A_CONST
>> :val "\2022-02-18\ 07
>> :00
>> :00.006547+02"
>> :location 7
>> }
>> :typeName
>> {TYPENAME
>> :names ("timestamptz")
>> :typeOid 0
>> :setof false
>> :pct_type false
>> :typmods <>
>> :typemod -1
>> :arrayBounds <>
>> :location 40
>> }
>> :location 38
>> }
>> :location 7
>> }
>> )
>> :fromClause <>
>> :whereClause <>
>> :groupClause <>
>> :groupDistinct false
>> :havingClause <>
>> :windowClause <>
>> :valuesLists <>
>> :sortClause <>
>> :limitOffset <>
>> :limitCount <>
>> :limitOption 0
>> :lockingClause <>
>> :withClause <>
>> :op 0
>> :all false
>> :larg <>
>> :rarg <>
>> }
>> :stmt_location 0
>> :stmt_len 51
>> }
>> )
>>
>> Best reagards,
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese:http://www.sraoss.co.jp
>>
>> > Maybe it’s not a big issue.
>> >
>> > But more than that the way postgresql using casting function is related
>> to
>> > the procvolatile.
>> >
>> > I believe the solution for pgpool should be related to which casting
>> > function postgres using.
>> >
>> > In case the procvolatile for that cast function is “i” the query should
>> be
>> > cached and if the procvolatile is “s” it shouldn’t.
>> >
>> > But maybe I am wrong.
>> >
>> > Do your magic.
>> >
>> > Thanks,
>> >
>> > Avi
>> >
>> > On Mon, 4 Jul 2022 at 14:36 Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
>> >
>> >> > Hi,
>> >> >
>> >> > I found some issue with timestamptz cast.
>> >> > See the following:
>> >> >
>> >> > 1.
>> >> >
>> >> > 2. Select ‘2022-02-18 07:00:00.006547+02’::timestamptz; ―> will
>> retrieved
>> >> > from cache
>> >> >
>> >> > 3. Set time zone to ‘Some time zone’;
>> >> >
>> >> > 4. Select ‘2022-02-18 07:00:00.006547+02’::timestamptz; ―> will
>> returned
>> >> > from cache but shouldn’t because the time zone has been changed.
>> >> >
>> >> > I think the right behaviour should be that if we using cast which
>> >> involved
>> >> > timezone like timestamptz or timetz these queries shouldn’t saved in
>> >> cache.
>> >> >
>> >> > What are your thoughts?
>> >>
>> >> You are right. Let me think about how to deal with the case.
>> >>
>> >> > Thanks,
>> >> >
>> >> > Avi.
>> >> >
>> >> > On Mon, 4 Jul 2022 at 11:41 Tatsuo Ishii <ishii at sraoss.co.jp> wrote:
>> >> >
>> >> >> Glad to hear that :-)
>> >> >>
>> >> >> > My mistake it’s working like a charm :)
>> >> >> >
>> >> >> > On Mon, 4 Jul 2022 at 11:32 Avi Raboah <avi.raboah at gmail.com>
>> wrote:
>> >> >> >
>> >> >> >> I added the patch and it still not working.
>> >> >> >> After your change the query
>> >> >> >> Select ‘2022-02-18 07:00:00.006547’::timestamp;
>> >> >> >>
>> >> >> >> Still not cached
>> >> >> >>
>> >> >> >> On Mon, 4 Jul 2022 at 11:21 Tatsuo Ishii <ishii at sraoss.co.jp>
>> wrote:
>> >> >> >>
>> >> >> >>> Hi,
>> >> >> >>>
>> >> >> >>> > Hi,
>> >> >> >>> >
>> >> >> >>> > I saw your patch thanks for that.
>> >> >> >>>
>> >> >> >>> You are welcome.
>> >> >> >>>
>> >> >> >>> > One question, in order to enable the not_used block you add,
>> Do I
>> >> >> need
>> >> >> >>> to
>> >> >> >>> > define this macro in the same page?
>> >> >> >>>
>> >> >> >>> No. You should *not* define NOT_USED symbol. Otherwise, the block
>> >> will
>> >> >> >>> be enabled, which is opposite to what the patch wants to do.
>> >> >> >>>
>> >> >> >>> > For example:
>> >> >> >>> > #define NOT_USED
>> >> >> >>> > #ifdef NOT_USED
>> >> >> >>> > …
>> >> >> >>> > …
>> >> >> >>> > #endif
>> >> >> >>> >
>> >> >> >>> > Or I don’t need to add that ?
>> >> >> >>> >
>> >> >> >>> > Thanks,
>> >> >> >>> >
>> >> >> >>> > Avi.
>> >> >> >>> >
>> >> >> >>> > On Mon, 4 Jul 2022 at 9:54 Avi Raboah <avi.raboah at gmail.com>
>> >> wrote:
>> >> >> >>> >
>> >> >> >>> >> Awesome, thanks!
>> >> >> >>> >>
>> >> >> >>> >> On Mon, 4 Jul 2022 at 9:52 Tatsuo Ishii <ishii at sraoss.co.jp>
>> >> wrote:
>> >> >> >>> >>
>> >> >> >>> >>> > Thanks a lot for your fast reaponse!
>> >> >> >>> >>> >
>> >> >> >>> >>> > Do you know when the fix will be available?
>> >> >> >>> >>>
>> >> >> >>> >>> I have just pushed the fix. It will available in the next
>> >> scheduled
>> >> >> >>> >>> release (Aug 18).
>> >> >> >>> >>>
>> >> >> >>> >>> https://pgpool.net/mediawiki/index.php/Roadmap
>> >> >> >>> >>>
>> >> >> >>> >>> If you need patches, you can grab from the git repository.
>> >> >> >>> >>>
>> >> >> >>> >>>
>> https://pgpool.net/mediawiki/index.php/Source_code_repository
>> >> >> >>> >>>
>> >> >> >>> >>> Best reagards,
>> >> >> >>> >>> --
>> >> >> >>> >>> Tatsuo Ishii
>> >> >> >>> >>> SRA OSS, Inc. Japan
>> >> >> >>> >>> English: http://www.sraoss.co.jp/index_en.php
>> >> >> >>> >>> Japanese:http://www.sraoss.co.jp
>> >> >> >>> >>>
>> >> >> >>> >>
>> >> >> >>>
>> >> >> >>
>> >> >>
>> >>
>>
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