On Tue, 29 Nov 2022 at 17:51, li jie <ggys...@gmail.com> wrote: > > I will continue to give feedback for this patch.
Thanks a lot, that will be very helpful for us. > 1. LIKE STORAGE > ``` > CREATE TABLE ctlt (a text, c text); > ALTER TABLE ctlt ALTER COLUMN c SET STORAGE EXTERNAL; > CREATE TABLE ctlt_storage (LIKE ctlt INCLUDING STORAGE); > ``` > > postgres=# \d+ ctlt_storage > > Table "public.ctlt_storage" > > Column | Type | Collation | Nullable | Default | Storage | > Compression | Stats target | Description > > --------+------+-----------+----------+---------+----------+-------------+--------------+------------- > > a | text | | | | extended | > | | > > c | text | | | | extended | > | | > > > It can be seen that the storage attribute in column C of table > ctlt_storage is not replicated. > > After the CREATE TABLE LIKE statement is converted, > the LIKE STORAGE attribute is lost because it is difficult to display > it in the CREATE TABLE syntax. > Maybe we need to add a statement to it, like 'ALTER TABLE ctlt_storage > ALTER COLUMN c SET STORAGE EXTERNAL;'. > > 2. Reference subcommand be dropped. > ``` > create table another (f1 int, f2 text, f3 text); > > alter table another > alter f1 type text using f2 || ' and ' || f3 || ' more', > alter f2 type bigint using f1 * 10, > drop column f3; > ``` > > The following error occurs downstream: > ERROR: column "?dropped?column?" does not exist at character 206 > STATEMENT: ALTER TABLE public.another DROP COLUMN f3 , ALTER COLUMN > f1 SET DATA TYPE pg_catalog.text COLLATE pg_catalog."default" USING > (((f2 OPERATOR(pg_catalog.||) ' and '::pg_catalog.text) > OPERATOR(pg_catalog.||) "?dropped?column?") OPERATOR(pg_catalog.||) ' > more'::pg_catalog.text), ALTER COLUMN f2 SET DATA TYPE pg_catalog.int8 > USING (f1 OPERATOR(pg_catalog.*) 10) > > Obviously, column f3 has been deleted and its name no longer exists. > Maybe we need to keep it and save it in advance like a drop object. > However, ATLER TABLE is complex, and this problem also occurs in > other similar scenarios. I will analyze these issues and post a patch to handle it. Regards, Vignesh