Re: [PATCH] Automatic HASH and LIST partition creation - Mailing list pgsql-hackers
| From | Pavel Borisov |
|---|---|
| Subject | Re: [PATCH] Automatic HASH and LIST partition creation |
| Date | |
| Msg-id | CALT9ZEH4YotxVz4n4CdeFO7fvkg1EczZJUAWpfzERNZzm4X6fg@mail.gmail.com Whole thread Raw |
| In response to | Re: [PATCH] Automatic HASH and LIST partition creation (Rahila Syed <rahilasyed90@gmail.com>) |
| Responses |
Re: [PATCH] Automatic HASH and LIST partition creation
(Pavel Borisov <pashkin.elfe@gmail.com>)
|
| List | pgsql-hackers |
Sorry for not being clear earlier, I mean the partition name 'tablename_partnum' can conflict with any existing table name.As per current impemetation, if I do the following it results in the table name conflict.postgres=# create table tbl_test_5_1(i int);CREATE TABLEpostgres=# CREATE TABLE tbl_test_5 (i int) PARTITION BY LIST((tbl_test_5)) CONFIGURATION (values in ('(1)'::tbl_test_5), ('(3)'::tbl_test_5) default partition tbl_default_5);ERROR: relation "tbl_test_5_1" already exists
Basically, it's the same thing when you try to create two tables with the same name. It is not specific to partition creation and common for every case that using any defaults, they can conflict with something existing. And in this case this conflict is explicitly processes as I see from output message.
In fact in PG there are other places when names are done in default way e.g. in aggregates regression test it is not surprise to find in PG13:
select min(f1), max(f1) from minmaxtest;
QUERY PLAN
---------------------------------------------------------------------------------------------
Result
InitPlan 1 (returns $0)
-> Limit
-> Merge Append
Sort Key: minmaxtest.f1
-> Index Only Scan using minmaxtesti on minmaxtest minmaxtest_1
Index Cond: (f1 IS NOT NULL)
-> Index Only Scan using minmaxtest1i on minmaxtest1 minmaxtest_2
Index Cond: (f1 IS NOT NULL)
-> Index Only Scan Backward using minmaxtest2i on minmaxtest2 minmaxtest_3
Index Cond: (f1 IS NOT NULL)
-> Index Only Scan using minmaxtest3i on minmaxtest3 minmaxtest_4
InitPlan 2 (returns $1)
-> Limit
-> Merge Append
Sort Key: minmaxtest_5.f1 DESC
-> Index Only Scan Backward using minmaxtesti on minmaxtest minmaxtest_6
Index Cond: (f1 IS NOT NULL)
-> Index Only Scan Backward using minmaxtest1i on minmaxtest1 minmaxtest_7
Index Cond: (f1 IS NOT NULL)
-> Index Only Scan using minmaxtest2i on minmaxtest2 minmaxtest_8
Index Cond: (f1 IS NOT NULL)
-> Index Only Scan Backward using minmaxtest3i on minmaxtest3 minmaxtest_9
where minmaxtest_<number> are the temporary relations and minmaxtest<number> are real partition names (last naming is unrelated to first)
Overall I don't see much trouble in any form of automatic naming. But there may be a convenience to provide fixed user-specified prefix to partition names.
Thank you,
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