Hi Wenjing,
Thanks for the new patch.
I saw with the patch(gtt_v23.patch), we are supporting the new concept "global temporary sequence"(i.e. session-specific sequence), is this intentional?
It was supported in earlier versions,
This causes the sequence built into the GTT to automatically become a "global temp sequence",
Such as create global temp table (a serial);
Like GTT, the global temp sequnce is used individually for each session.
Recently, I added the global temp sequence syntax so that it can be created independently.
The purpose of this is to enable such sequence built into the GTT to support pg_dump and pg_restore.
Wenjing
postgres=# create global temporary sequence gt_seq;
CREATE SEQUENCE
postgres=# create sequence seq;
CREATE SEQUENCE
postgres=# \d+
List of relations
Schema | Name | Type | Owner | Persistence | Size | Description
--------+--------+----------+-------+-------------+------------+-------------
public | gt_seq | sequence | edb | session | 8192 bytes |
public | seq | sequence | edb | permanent | 8192 bytes |
(2 rows)
postgres=# select nextval('gt_seq'), nextval('seq');
nextval | nextval
---------+---------
1 | 1
(1 row)
postgres=# select nextval('gt_seq'), nextval('seq');
nextval | nextval
---------+---------
2 | 2
(1 row)
-- Exit and re-connect to psql prompt:
postgres=# \q
[edb@localhost bin]$ ./psql postgres
psql (13devel)
Type "help" for help.
postgres=# select nextval('gt_seq'), nextval('seq');
nextval | nextval
---------+---------
1 | 3
(1 row)
postgres=# select nextval('gt_seq'), nextval('seq');
nextval | nextval
---------+---------
2 | 4
(1 row)
On 3/27/20 10:55 AM, 曾文旌 wrote:
Hi Wenjing,
This patch(gtt_v21_pg13.patch) is not applicable on PG HEAD, I hope you have prepared the patch on top of some previous commit.
Could you please rebase the patch which we can apply on HEAD ?
Yes, It looks like the built-in functions are in conflict with new code.
This error message looks wrong to me-
postgres=# reindex table concurrently t ;
ERROR: cannot create indexes on global temporary tables using concurrent mode
postgres=#
Better message would be-
ERROR: cannot reindex global temporary tables concurrently
I found that the local temp table automatically disables concurrency mode.
so, I made some improvements, The reindex GTT behaves the same as the local temp table.
Wenjing
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