how best to specify table constraints with "create table as " - Mailing list pgsql-general

From Kevin Wilkinson
Subject how best to specify table constraints with "create table as "
Date
Msg-id 39455b88-04a5-ea0c-1016-16132b15d838@gmail.com
Whole thread Raw
In response to Methods to quickly spin up copies of an existing databases  (Arjun Ranade <ranade@nodalexchange.com>)
List pgsql-general
i want to recluster an immutable table without locking the table and then add the table as a partition of a parent table. my plan was:
create table tbl_cpy as select * from tbl order by c1 asc;
alter table tbl_cpy add constraint c1 not null, c1>=lo c1<hi;
alter table tbl_parent attach partition tbl_cpy for values from (lo) to (hi);
i want this to run quickly. so, i populate the table with a parallel query (using create table as ...). i do NOT want attach partition to rescan the table (which it does to validate the value range) so i have to explicitly add constraints to tbl_cpy. but adding these constraints itself causes a scan of the table.

so, i want to specify the constraints when the table is created. but that seems not possible. if i first create an empty table with constraints, then i cannot populate it with a parallel query (since insert into is not parallel).

am i missing something? any ideas?

thanks,

kevin

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