Is it possible to rename multiple columns in a single statement, something along the lines of:
ALTER TABLE Users
RENAME COLUMN userName TO user_name,
RENAME COLUMN realName TO real_name;
No.
While other actions can be combined, that's not possible with RENAME
. The manual:
All the forms of
ALTER TABLE
that act on a single table, exceptRENAME
,SET SCHEMA
,ATTACH PARTITION
, andDETACH PARTITION
can be combined into a list of multiple alterations to be applied together.
Since RENAME
is a tiny operation on a system catalog, there is no harm in running multiple statements. Do it in a single transaction to minimize locking overhead.
Other actions like ALTER COLUMN ... SET TYPE
are potentially expensive because they may have to rewrite the whole table. With big tables it would be wise to do as much as possible in a single statement.