Is it possible to dump tables and schemas that are accessible to me only in PostgreSQL?
First find the relations you have access to (this can be tweaked to pull schemas too)
with relnames as (SELECT relname FROM pg_class
WHERE relkind='r' and relnamespace = (select oid from pg_namespace where nspname = 'public'))
select array_agg(relname) from relnames WHERE has_table_privilege(SESSION_USER, relname, 'SELECT');
Now we aren't quite done now because that just creates an array of tables we have access to. We now need to change this to use array_to_string to get something we can feed into pg_dump:
with relnames as (SELECT relname FROM pg_class
WHERE relkind='r' and relnamespace = (select oid from pg_namespace where nspname = 'public'))
select array_to_string(array_agg(relname), ' -t ') from relnames WHERE has_table_privilege(SESSION_USER, relname, 'SELECT');
the above queries can be tweaked (changing the pg_namespace subquery) to pull namespaces you have access to and you could change it to a join to pull fully qualified table names.
Related
I am trying to write a function to determine the sequences related to a given table name, in the query within the function, I went with something like this:
select s.relname as sec from pg_class s
join pg_depend d on d.objid=s.oid and d.classid='pg_class'::regclass
and d.refclassid='pg_class'::regclass
join pg_class t on t.oid=d.refobjid
join pg_namespace n on n.oid=t.relnamespace
join pg_attribute a on a.attrelid=t.oid and a.attnum=d.refobjsubid
where s.relkind='S' and t.relname = 'table_name'
However it doesn't seem to find all the sequences that exists, i.e. for some tables, it just doesn't find the related sequences, but for certain ones it does.
I have a database with plenty of tables.
I want to tidy up relations that do not fit namewise anymore, due to name changes of the tables.
I was able to fix the constraints, but I am not able to put the lines together to list the sequences and the related columns. As pgAdmin shows under dependencies the column a sequence is connected to, it should be possible to create a SELECT to show sequences and their related column.
Try this:
SELECT a.attrelid::regclass AS table_name,
a.attname AS column_name,
pg_get_serial_sequence(a.attrelid::regclass::text, a.attname) AS sequence_name
FROM pg_attribute AS a
JOIN pg_class AS t ON a.attrelid = t.oid
WHERE t.relkind IN ('r', 'P')
AND NOT a.attisdropped
AND pg_get_serial_sequence(a.attrelid::regclass::text, a.attname) IS NOT NULL;
I just created an new database and it already takes up 7MB. Do you know what is taking up this much space? Is there a way to get the "real" size of the database used as in how much data is stored?
0f41ba72-a1ea-4516-a9f0-de8a3609bc4a=> select pg_size_pretty(pg_database_size(current_database()));
pg_size_pretty
----------------
7055 kB
(1 row)
0f41ba72-a1ea-4516-a9f0-de8a3609bc4a=> \dt
No relations found.
Well, even you don't created any relation yet the new database is not empty. When a CREATE DATABASE is issued, Postgres copy a TEMPLATE database - which comes with catalog tables - to a new database. In fact, "Nothing is created, everything is transformed". You can use commands below to inspect this:
--Size per table
SELECT pg_size_pretty(pg_total_relation_size(oid)), relname FROM pg_class WHERE relkind = 'r' AND NOT relisshared;
--Total size
SELECT pg_size_pretty(sum(pg_total_relation_size(oid))) FROM pg_class WHERE relkind = 'r' AND NOT relisshared;
--Total size of databases
SELECT pg_size_pretty(pg_database_size(oid)), datname FROM pg_database;
A quote from the docs:
By default, the new database will be created by cloning the standard
system database template1.
An empty database contains system catalogs and The Information Schema.
Execute this query to see them:
select nspname as schema, relname as table, pg_total_relation_size(c.oid)
from pg_class c
join pg_namespace n on n.oid = relnamespace
order by 3 desc;
schema | table | pg_total_relation_size
--------------------+-----------------------------+------------------------
pg_catalog | pg_depend | 1146880
pg_catalog | pg_proc | 950272
pg_catalog | pg_rewrite | 589824
pg_catalog | pg_attribute | 581632
... etc
You can get the total size of non-system relations with the query:
select sum(pg_total_relation_size(c.oid))
from pg_class c
join pg_namespace n on n.oid = relnamespace
where nspname not in ('information_schema', 'pg_catalog', 'pg_toast');
The query returns null on empty database.
Every PostgreSQL databases has own system catalogue .. 7MB. So your numbers are correct. PostgreSQL is designed for client-server architecture and 1GB and longer databases - so this cost is not significant.
If you need reduced space allocation, you can try embedded databases like SQLite or Firebird.
My database is postgresql 9.3.5
we created some materialized views. we are able seeing those are in views folder through pgadmin tool
but our issue is we are not able to finding out those materialized views in metadata
we checked in information_schema and all catalogs.
we found all tables,views and schemas except materialized views in metadata
Thanks
Ragav
A query like this will give you an overview of the materialized views and their columns:
select ns.nspname as schemaname,
mv.relname as matviewname,
string_agg(atr.attname ||' '||pg_catalog.format_type(atr.atttypid, NULL), ', ') as columns
from pg_class mv
join pg_namespace ns on mv.relnamespace = ns.oid
join pg_attribute atr
on atr.attrelid = mv.oid
and atr.attnum > 0
and not atr.attisdropped
where mv.relkind = 'm'
group by ns.nspname, mv.relname;
What is the recommended way to figure out if a user got a certain right (e.g. select or execute) on a certain class (e.g. table or function) in PostgreSQL?
At the moment I got something like
aclcontains(
someColumnWithAclitemArray,
makeaclitem(userOid,grantorOid,someRight,false))
but it's terrible since I have to check for every grantorOid that is possible and for every userOid the user can belong to.
On a related note: what are the possible rights you can test for?
I haven't found any documentation but reading the source code I guess:
INSERT
SELECT
UPDATE
DELETE
TRUNCATE
REFERENCES
TRIGGER
EXECUTE
USAGE
CREATE
CONNECT
There also seems to be a CREATE TEMP right, but I can't figure out the correct text to use in the makeaclitem-function.
I've found that a better approach (and I seem to remember this was taken from some queries built into psql, or maybe the information_schema views) is to use the has_*_privilege functions, and simply apply them to a set of all possible combinations of user and object. This will take account of having access to an object via some group role as well.
For example, this will show which users have which access to non-catalogue tables and views:
select usename, nspname || '.' || relname as relation,
case relkind when 'r' then 'TABLE' when 'v' then 'VIEW' end as relation_type,
priv
from pg_class join pg_namespace on pg_namespace.oid = pg_class.relnamespace,
pg_user,
(values('SELECT', 1),('INSERT', 2),('UPDATE', 3),('DELETE', 4)) privs(priv, privorder)
where relkind in ('r', 'v')
and has_table_privilege(pg_user.usesysid, pg_class.oid, priv)
and not (nspname ~ '^pg_' or nspname = 'information_schema')
order by 2, 1, 3, privorder;
The possible privileges are detailed in the description of the has_*_privilege functions at http://www.postgresql.org/docs/current/static/functions-info.html#FUNCTIONS-INFO-ACCESS-TABLE.
'CREATE TEMP' is a database-level privilege: it permits a user to use a pg_temp_* schema. It can be tested with has_database_privilege(useroid, datoid, 'TEMP').
Take a look at the "Access Privilege Inquiry Functions" and also the "GRANT" reference page.
Because Redshift is supporting values() only in INSERT INTO queries, the below query can be used with the obviously not-so-nice union all select.
select usename, nspname || '.' || relname as relation,
case relkind when 'r' then 'table' when 'v' then 'view' end as relation_type,
priv
from pg_class join pg_namespace on pg_namespace.oid = pg_class.relnamespace,
pg_user,
(select 'select' as priv,1 as privorder union all select 'insert',2 union all select 'update',3 union all select 'delete',4)
where relkind in ('r', 'v')
and has_table_privilege(pg_user.usesysid, pg_class.oid, priv)
and not (nspname ~ '^pg_' or nspname = 'information_schema')
order by 2, 1, 3, privorder;
Edit:
Also, I realized, that in our db Dataiku creates tables that can have CAPITAL letter in them, so, if table not exist error happens, you should use the lower() function