I have replication slot which I want to delete but when I do delete I got an error that I can't delete from view. Any ideas?
postgres=# SELECT * FROM pg_replication_slots ;
slot_name | plugin | slot_type | datoid | database | active | xmin | catalog_xmin | restart_lsn
--------------+--------------+-----------+--------+----------+--------+------+--------------+-------------
bottledwater | bottledwater | logical | 12141 | postgres | t | | 374036 | E/FE8D9010
(1 row)
postgres=# delete from pg_replication_slots;
ERROR: cannot delete from view "pg_replication_slots"
DETAIL: Views that do not select from a single table or view are not automatically updatable.
HINT: To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.
postgres=#
Use pg_drop_replication_slot:
select pg_drop_replication_slot('bottledwater');
See the docs and this blog.
The replication slot must be inactive, i.e. no active connections. So if there's a streaming replica using the slot you must stop the streaming replica. Or you can change its recovery.conf so it doesn't use a slot anymore and restart it.
As a complement to the accepted answer, I'd like to mention that following command will not fail in case the slot does not exist (this was useful for me because I scripted that).
select pg_drop_replication_slot(slot_name) from pg_replication_slots where slot_name = 'bottledwater';
Related
I was trying to implement code through flyway:
create index concurrently if not exists api_client_system_role_idx2 on profile.api_client_system_role (api_client_id);
create index concurrently if not exists api_client_system_role_idx3 on profile.api_client_system_role (role_type_id);
create index concurrently if not exists api_key_idx2 on profile.api_key (api_client_id);
However flyway sessions were blocking each other and script is in "pending" state.
| Versioned | 20.1 | add email verification table | SQL | 2021-11-01 21:55:52 | Success |
| Versioned | 21.1 | create role for doc api | SQL | 2021-11-01 21:55:52 | Success |
| Versioned | 22 | create indexes for profile | SQL | 2022-10-21 10:23:41 | Success |
| Versioned | 23 | test flyway | SQL | | Pending |
+-----------+---------+----------------------------------------------+--------+---------------------+---------+
Flyway: Flyway Community Edition 9.3.1 by Redgate
Database: Postgresql 14.4
Can you please advice how to properly implement creating indexes concurrently in postgresql?
I've tried simply to kill blocking session and let the script to continue, however then implementation failed and scripts stayed in "Pending" status.
I have imported a local PostgreSQL database to a managed cluster on Digital Ocean. It will be used with a Python app that will also be hosted on Digital Ocean. I used pg_dump and pg_restore to achieve the import. Now, to make sure the import was successful, I am running some psql queries and commands via my MacOS terminal app that is set up with zsh and it connects via a shell script that prompts me for host, database name, port, user and password. I am successful in connecting to the managed cluster this way, and I can execute some queries with no problem, while others are causing errors. For example:
my_support=> \dt
List of relations
Schema | Name | Type | Owner
--------+----------------------+-------+---------
public | ages | table | doadmin
public | articles | table | doadmin
public | challenges | table | doadmin
public | cities | table | doadmin
public | comments | table | doadmin
public | messages | table | doadmin
public | relationships | table | doadmin
public | topics | table | doadmin
public | users | table | doadmin
(9 rows)
my_support=> \dt+
sh: more: command not found
my_support=>
Also:
my_support=> SELECT id,sender_id FROM messages;
id | sender_id
----+-----------
1 | 1
2 | 2
3 | 4
4 | 1
5 | 2
(5 rows)
my_support=> SELECT * FROM messages;
sh: more: command not found
my_support=>
So the terminal app seems to dislike certain characters, such as * and +, but I can't find any documentation that tells me I should escape them, or how. I tried backslash in front of them, but it did not work. And what's more confusing is that these very same queries are successful when I connected to my LOCAL copy of the database, using the very same terminal app, launched from the very same shell script.
In case it's helpful, here's what I see in the CLI when I connect:
psql (14.1, server 14.2)
SSL connection (protocol: TLSv1.3, cipher: <alphanumeric string here>, bits: 256, compression: off)
Type "help" for help.
my_support=>
Does it matter that my local PostgreSQL version is 14.1 and the server is 14.2? I'm assuming the "server" refers to the hosted environment, but it seems like something as basic as "SELECT * FROM" should not be version-dependent.
Ultimately what matters is whether my Python app (which uses psycopg library to talk to PostgreSQL) can run those queries, and I haven't test that yet. But it sure would be handy to test things on the managed cluster using my local terminal app.
BTW, I have an open ticket with Digital Ocean to answer this question, but I find SO to be faster and more helpful in most cases.
psql is trying to use a pager to display results that are longer than the number of lines in the terminal. The error message
more: command not found
indicates that the pager (more) it tries to use is not available. You can turn off the use of a pager:
\pset pager off
or set a different command to be used as the pager. See the manual for details
I have a psql database that I want to do alembic migrations on. After the migrations, locks are still present:
SELECT l.pid, l.locktype, l.mode
FROM pg_locks l
INNER JOIN pg_stat_activity s ON (l.pid = s.pid) where usename='migrations_user';
pid | locktype | mode
-------+------------+-----------------
19918 | relation | AccessShareLock
19918 | relation | AccessShareLock
19918 | relation | AccessShareLock
19918 | relation | AccessShareLock
19918 | virtualxid | ExclusiveLock
(5 rows)
The database is owned by db_owner and I ran grant db_owner to migrations_user; so it has all the permissions to run the migration, and the migration succeeds. But a followup migration on the same table would fail due to these locks, and I need to go in and manually run pg_terminate_backend on these locks to proceed.
What could be causing this? The alembic migration code is pretty standard:
def run_migrations_online():
"""Run migrations in 'online' mode.
In this scenario we need to create an Engine
and associate a connection with the context.
"""
LOG.info("Running run_migrations_online")
connectable = create_engine(get_conn_url_from_env())
with connectable.connect() as connection:
context.configure(connection=connection, target_metadata=target_metadata)
with context.begin_transaction():
context.run_migrations()
connectable.dispose()
I've postgresql-9.4 up and running, and I've enabled pg_stat_statements module lately by the help of official documentation.
But I'm getting following error upon usage:
postgres=# SELECT * FROM pg_stat_statements;
ERROR: relation "pg_stat_statements" does not exist
LINE 1: SELECT * FROM pg_stat_statements;
postgres=# SELECT pg_stat_statements_reset();
ERROR: function pg_stat_statements_reset() does not exist
LINE 1: SELECT pg_stat_statements_reset();
I'm logged in to psql with the postgres user.
I've also checked the available extension lists:
postgres=# SELECT * FROM pg_available_extensions WHERE name = 'pg_stat_statements'
;
name | default_version | installed_version | comment
--------------------+-----------------+-------------------+-----------------------------------------------------------
pg_stat_statements | 1.2 | | track execution statistics of all SQL statements executed
(1 row)
And here's the results of the extension versions query:
postgres=# SELECT * FROM pg_available_extension_versions WHERE name = 'pg_stat_statements';
name | version | installed | superuser | relocatable | schema | requires | comment
--------------------+---------+-----------+-----------+-------------+--------+----------+-----------------------------------------------------------
pg_stat_statements | 1.2 | f | t | t | | | track execution statistics of all SQL statements executed
(1 row)
Any help will be appreciated.
Extension isn't installed:
SELECT *
FROM pg_available_extensions
WHERE
name = 'pg_stat_statements' and
installed_version is not null;
If the table is empty, create the extension:
CREATE EXTENSION pg_stat_statements;
I've faced with this issue at configuring Percona Monitoring and Management (PMM) because by some strange reason PMM connecting to database with name postgres, so pg_stat_statements extension have to be created in this database:
yourdb# \c postgres
postgres# CREATE EXTENSION pg_stat_statements SCHEMA public;
Follow below steps:
Create the extension
CREATE EXTENSION pg_stat_statements;
Change in config
alter system set shared_preload_libraries='pg_stat_statements';
Restart
$ systemctl restart postgresql
Verify changes applied or not.
select * from pg_file_Settings where name='shared_preload_libraries';
The applied attribute must be 'true'.
I Had the same issue when deploying the environment using liquibase for the first time.
I understand that my reply maybe is not related with your problem but was the first google result so I think that other guys like me can arrive here with my the same Liquibase Issue.
These are PosGreSQL metadata tables that are retrieved by liquibase when you generate your first xml file.
In my case it only was useless autogenerated code, so I solved it deleteing these lines:
<changeSet author="martinlarizzate (generated)" id="1588181532394-7">
<createView fullDefinition="false" viewName="pg_stat_statements"> SELECT pg_stat_statements.userid,
pg_stat_statements.dbid,
pg_stat_statements.queryid,
pg_stat_statements.query,
pg_stat_statements.calls,
pg_stat_statements.total_time,
pg_stat_statements.min_time,
pg_stat_statements.max_time,
pg_stat_statements.mean_time,
pg_stat_statements.stddev_time,
pg_stat_statements.rows,
pg_stat_statements.shared_blks_hit,
pg_stat_statements.shared_blks_read,
pg_stat_statements.shared_blks_dirtied,
pg_stat_statements.shared_blks_written,
pg_stat_statements.local_blks_hit,
pg_stat_statements.local_blks_read,
pg_stat_statements.local_blks_dirtied,
pg_stat_statements.local_blks_written,
pg_stat_statements.temp_blks_read,
pg_stat_statements.temp_blks_written,
pg_stat_statements.blk_read_time,
pg_stat_statements.blk_write_time
FROM pg_stat_statements(true) pg_stat_statements(userid, dbid, queryid, query, calls, total_time, min_time, max_time, mean_time, stddev_time, rows, shared_blks_hit, shared_blks_read, shared_blks_dirtied, shared_blks_written, local_blks_hit, local_blks_read, local_blks_dirtied, local_blks_written, temp_blks_read, temp_blks_written, blk_read_time, blk_write_time);</createView>
</changeSet>
Im running Postgres 8.3 and I am having trouble running AN ALTER TABLE ADD COLUMN statement which seems to be blocked by an AccessShareLock when I run this query
SELECT t.relname,l.locktype,page,virtualtransaction,pid,mode,granted FROM pg_locks l, pg_stat_all_tables t WHERE l.relation=t.relid ORDER BY relation asc;
The table's name is dealer.
relname | locktype | page | virtualtransaction | pid | mode | granted
dealer | relation | | 2/40 | 12719 | AccessExclusiveLock | f
dealer | relation | | -1/154985751 | | AccessShareLock | t
I also ran
SELECT * FROM pg_prepared_xacts
That returned
transaction | gid | prepared | owner | database
154985751 | 131075_MS1hMzIwM2E3OmIwMjM6NTQxMGY0MzE6MWM1ZTg5OQ==_YTMyMDNhNzpiMDIzOjU0MTBmNDMxOjFjNWU4OWM= | 2014-09-19 08:01:49.650957+10 | user | database
The transaction id 154985751 looks similar to the virtualtransaction in the pg_locks table -1/154985751
I ran this command to view any processes that may be running queries on the database
ps axu | grep postgres | grep -v idle
and have confirmed there are no other processes running queries on the database.
The log file shows this after the query has been run
2014-11-14 17:25:00.794 EST (pid: 12719) LOG: statement: BEGIN;
2014-11-14 17:25:00.794 EST (pid: 12719) LOG: statement: ALTER TABLE dealer ADD bullet1 varchar;
2014-11-14 17:25:01.795 EST (pid: 12719) LOG: process 12719 still waiting for AccessExclusiveLock on relation 2321398 of database 2321293 after 1000.133 ms
2014-11-14 17:25:01.795 EST (pid: 12719) STATEMENT: ALTER TABLE dealer ADD bullet1 varchar;
What could be causing the AccessShareLock on the dealer table? Im guessing it has something to do with the transaction 154985751 is there a way to terminate a transaction with using the virtual id?
You have a prepared transaction in place. Prepared transactions - those where PREPARE TRANSACTION but not COMMIT PREPARED or ROLLBACK PREPARED has been run - hold locks, just like normal running transactions do.
Prepared transactions may be used by XA transaction managers, JTA, etc, not necessarily directly by your app. Many queuing systems use them too. If you don't know what the transaction is and you commit it or roll it back you may disrupt something that is relying on two-phase commit.
If you are certain that you know what it is you can:
COMMIT PREPARED '131075_MS1hMzIwM2E3OmIwMjM6NTQxMGY0MzE6MWM1ZTg5OQ==_YTMyMDNhNzpiMDIzOjU0MTBmNDMxOjFjNWU4OWM='
or
ROLLBACK PREPARED '131075_MS1hMzIwM2E3OmIwMjM6NTQxMGY0MzE6MWM1ZTg5OQ==_YTMyMDNhNzpiMDIzOjU0MTBmNDMxOjFjNWU4OWM='
depending on whether you wish to commit or abort the prepared xact.
You can't inspect the transaction to see what it did/does, you need to figure out what app/tool created it and why if you don't know what it is.
The identifier looks suspiciously like [number]_[base64]_[base64] so lets see what we can do with that:
postgres=> SELECT decode((string_to_array('131075_MS1hMzIwM2E3OmIwMjM6NTQxMGY0MzE6MWM1ZTg5OQ==_YTMyMDNhNzpiMDIzOjU0MTBmNDMxOjFjNWU4OWM=','_'))[2], 'base64');
decode
------------------------------------------------------------------
\x312d613332303361373a623032333a35343130663433313a31633565383939
(1 row)
postgres=> SELECT decode((string_to_array('131075_MS1hMzIwM2E3OmIwMjM6NTQxMGY0MzE6MWM1ZTg5OQ==_YTMyMDNhNzpiMDIzOjU0MTBmNDMxOjFjNWU4OWM=','_'))[3], 'base64');
decode
--------------------------------------------------------------
\x613332303361373a623032333a35343130663433313a31633565383963
(1 row)
Hm, looks like ASCII or similar, lets see:
postgres=> SELECT convert_from(decode((string_to_array('131075_MS1hMzIwM2E3OmIwMjM6NTQxMGY0MzE6MWM1ZTg5OQ==_YTMyMDNhNzpiMDIzOjU0MTBmNDMxOjFjNWU4OWM=','_'))[2], 'base64'), 'utfpostgres=> SELECT convert_from(decode((string_to_array('131075_MS1hMzIwM2E3OmIwMjM6NTQxMGY0MzE6MWM1ZTg5OQ==_YTMyMDNhNzpiMDIzOjU0MTBmNDMxOjFjNWU4OWM=','_'))[2], 'base64'), 'utf-8');
convert_from
---------------------------------
1-a3203a7:b023:5410f431:1c5e899
(1 row)
postgres=> SELECT convert_from(decode((string_to_array('131075_MS1hMzIwM2E3OmIwMjM6NTQxMGY0MzE6MWM1ZTg5OQ==_YTMyMDNhNzpiMDIzOjU0MTBmNDMxOjFjNWU4OWM=','_'))[3], 'base64'), 'utf-8');
convert_from
-------------------------------
a3203a7:b023:5410f431:1c5e89c
(1 row)
Looks vaguely GUID/UUID-ish, with odd formatting and grouping.
Maybe those identifiers will help you figure out where the xact came from.
BTW, 8.3 is exceedingly obsolete. Plan your upgrade.