On 2020-07-07 01:08, Tom Lane wrote:
Alvaro Herrera <alvhe...@2ndquadrant.com> writes:
On 2020-Jul-05, Anna Akenteva wrote:
-- Swapping primary key's index for an equivalent index,
-- but with INCLUDE-d attributes.
CREATE UNIQUE INDEX new_idx ON target_tbl (id) INCLUDE (info);
ALTER TABLE target_tbl ALTER CONSTRAINT target_tbl_pkey USING INDEX
new_idx;
ALTER TABLE referencing_tbl ALTER CONSTRAINT
referencing_tbl_id_ref_fkey
USING INDEX new_idx;
How is this state represented by pg_dump?
Even if it's possible to represent, I think we should flat out reject
this "feature". Primary keys that aren't primary keys don't seem like
a good idea. For one thing, it won't be possible to describe the
constraint accurately in the information_schema.
Do you think it could still be a good idea if we only swap the
relfilenodes of indexes, as it was suggested in [1]? The original use
case was getting rid of index bloat, which is now solved by REINDEX
CONCURRENTLY, but this feature still has its own use case of adding
INCLUDE-d columns to constraint indexes.
[1]
https://www.postgresql.org/message-id/flat/CABwTF4UxTg%2BkERo1Nd4dt%2BH2miJoLPcASMFecS1-XHijABOpPg%40mail.gmail.com
--
Anna Akenteva
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
