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[bug report] About create table like feature's bug 2+ messages / 2 participants [nested] [flat]
* [bug report] About create table like feature's bug @ 2025-10-31 07:14 =?gb18030?B?ZGVuZ2thaQ==?= <784523565@qq.com> 0 siblings, 1 reply; 2+ messages in thread From: dengkai @ 2025-10-31 07:14 UTC (permalink / raw) To: pgsql-bugs <pgsql-bugs@lists.postgresql.org> hi, all When I use 'create table like' command to create a table with 'including indexes' options, database return an unexpected result. Look at the following sql statement. postgres=# create table t1(c1 int, c2 char(10)); CREATE TABLE postgres=# create index idx1 on t1(c1); CREATE INDEX postgres=# \d+ t1 Table "public.t1" Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description --------+---------------+-----------+----------+---------+----------+-------------+--------------+------------- c1 | integer | | | | plain | | | c2 | character(10) | | | | extended | | | Indexes: "idx1" btree (c1) Access method: heap postgres=# create table t2(like t1 including indexes); CREATE TABLE postgres=# \d+ t2 Table "public.t2" Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description --------+---------------+-----------+----------+---------+----------+-------------+--------------+------------- c1 | integer | | | | plain | | | c2 | character(10) | | | | extended | | | Indexes: "t2_c1_idx" btree (c1) Access method: heap postgres=# select version(); version ------------------------------------------------------------------------------------------------------------ PostgreSQL 16devel on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44), 64-bit (1 row) I did not use 'including storage' option in 'create table like' statement, but there is an extended attribute on t2.c2. It seems that the 'including storage' option is not effective, the default behavior of database is to bring the storage attribute from original table columns to the new table. I found this phenomenon on pg15.5 version. And it should also be present on pg18. Is this a bug？ I look forward to your reply. best regards dengkai dengkai 784523565@qq.com ^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: [bug report] About create table like feature's bug @ 2025-10-31 08:50 Laurenz Albe <laurenz.albe@cybertec.at> parent: =?gb18030?B?ZGVuZ2thaQ==?= <784523565@qq.com> 0 siblings, 0 replies; 2+ messages in thread From: Laurenz Albe @ 2025-10-31 08:50 UTC (permalink / raw) To: dengkai <784523565@qq.com>; pgsql-bugs <pgsql-bugs@lists.postgresql.org> On Fri, 2025-10-31 at 15:14 +0800, dengkai wrote: > When I use 'create table like' command to create a table with 'including indexes' options, database return > an unexpected result. Look at the following sql statement. > > postgres=# create table t1(c1 int, c2 char(10)); > CREATE TABLE > postgres=# create index idx1 on t1(c1); > CREATE INDEX > postgres=# \d+ t1 > Table "public.t1" > Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description > --------+---------------+-----------+----------+---------+----------+-------------+--------------+------------- > c1 | integer | | | | plain | | | > c2 | character(10) | | | | extended | | | > Indexes: > "idx1" btree (c1) > Access method: heap > > postgres=# create table t2(like t1 including indexes); > CREATE TABLE > postgres=# \d+ t2 > Table "public.t2" > Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description > --------+---------------+-----------+----------+---------+----------+-------------+--------------+------------- > c1 | integer | | | | plain | | | > c2 | character(10) | | | | extended | | | > Indexes: > "t2_c1_idx" btree (c1) > Access method: heap > > postgres=# select version(); > version > ------------------------------------------------------------------------------------------------------------ > PostgreSQL 16devel on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44), 64-bit > (1 row) That's an alpha or beta version of an old release. Bad choice. > I did not use 'including storage' option in 'create table like' statement, but there is an extended attribute on t2.c2. > It seems that the 'including storage' option is not effective, the default behavior of database is to bring the storage > attribute from original table columns to the new table. > > I found this phenomenon on pg15.5 version. And it should also be present on pg18. Is this a bug？ No, that is not a bug. EXTENDED is the default storage method. See this example: test=> CREATE TABLE t (c text STORAGE EXTERNAL); CREATE TABLE test=> \d+ t Table "laurenz.t" Column │ Type │ Collation │ Nullable │ Default │ Storage │ Compression │ Stats target │ Description ════════╪══════╪═══════════╪══════════╪═════════╪══════════╪═════════════╪══════════════╪═════════════ c │ text │ │ │ │ external │ │ │ Access method: heap test=> CREATE TABLE t1 (LIKE t); CREATE TABLE test=> \d+ t1 Table "laurenz.t1" Column │ Type │ Collation │ Nullable │ Default │ Storage │ Compression │ Stats target │ Description ════════╪══════╪═══════════╪══════════╪═════════╪══════════╪═════════════╪══════════════╪═════════════ c │ text │ │ │ │ extended │ │ │ Access method: heap Yours, Laurenz Albe ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2025-10-31 08:50 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2025-10-31 07:14 [bug report] About create table like feature's bug =?gb18030?B?ZGVuZ2thaQ==?= <784523565@qq.com> 2025-10-31 08:50 ` Laurenz Albe <laurenz.albe@cybertec.at>
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