Grants not working on partitions

On 9/28/24 04:02, Lok P wrote:

Hi,
While we are creating any new tables, we used to give SELECT privilege
on the newly created tables using the below command. But we are seeing
now , in case of partitioned tables even if we had given the privileges
in the same fashion, the user is not able to query specific partitions
but only the table. Commands like "select * from
schema1.<partition_name> " are erroring out with the "insufficient
privilege" error , even if the partition belongs to the same table.

Grant SELECT ON <table_name> to <user_name>;

Grant was seen as a one time command which needed while creating the
table and then subsequent partition creation for that table was handled
by the pg_partman extension. But that extension is not creating or
copying any grants on the table to the users. We were expecting , once
the base table is given a grant , all the inherited partitions will be
automatically applied to those grants. but it seems it's not working
that way. So is there any other way to handle this situation?

The docs are there for a reason:

https://github.com/pgpartman/pg_partman/blob/master/doc/pg_partman.md#child-table-property-inheritance

"Privileges & ownership are NOT inherited by default. If enabled by
pg_partman, note that this inheritance is only at child table creation
and isn't automatically retroactive when changed (see
reapply_privileges()). Unless you need direct access to the child
tables, this should not be needed. You can set the inherit_privileges
option if this is needed (see config table information below)."

And:

"reapply_privileges(
p_parent_table text
)
RETURNS void

This function is used to reapply ownership & grants on all child
tables based on what the parent table has set.
Privileges that the parent table has will be granted to all child
tables and privileges that the parent does not have will be revoked
(with CASCADE).
Privileges that are checked for are SELECT, INSERT, UPDATE, DELETE,
TRUNCATE, REFERENCES, & TRIGGER.
Be aware that for large partition sets, this can be a very long
running operation and is why it was made into a separate function to run
independently. Only privileges that are different between the parent &
child are applied, but it still has to do system catalog lookups and
comparisons for every single child partition and all individual
privileges on each.
p_parent_table - parent table of the partition set. Must be schema
qualified and match a parent table name already configured in pg_partman.
"

In other databases(say like Oracle) we use to create standard
"roles"(Read_role, Write_role etc..) and then provide grants to the user
through those roles. And the objects were given direct grants to those
roles. Similarly here in postgres we were granting "read" or "write"
privileges on objects to the roles and letting the users login to the
database using those roles and thus getting all the read/write
privileges assigned to those roles. Are we doing anything wrong?

Regards
Lok

--
Adrian Klaver
adrian.klaver@aklaver.com

On Sat, Sep 28, 2024 at 8:46 PM Adrian Klaver <adrian.klaver@aklaver.com>
wrote:

On 9/28/24 04:02, Lok P wrote:

Hi,
While we are creating any new tables, we used to give SELECT privilege
on the newly created tables using the below command. But we are seeing
now , in case of partitioned tables even if we had given the privileges
in the same fashion, the user is not able to query specific partitions
but only the table. Commands like "select * from
schema1.<partition_name> " are erroring out with the "insufficient
privilege" error , even if the partition belongs to the same table.

Grant SELECT ON <table_name> to <user_name>;

Grant was seen as a one time command which needed while creating the
table and then subsequent partition creation for that table was handled
by the pg_partman extension. But that extension is not creating or
copying any grants on the table to the users. We were expecting , once
the base table is given a grant , all the inherited partitions will be
automatically applied to those grants. but it seems it's not working
that way. So is there any other way to handle this situation?

The docs are there for a reason:

https://github.com/pgpartman/pg_partman/blob/master/doc/pg_partman.md#child-table-property-inheritance

"Privileges & ownership are NOT inherited by default. If enabled by
pg_partman, note that this inheritance is only at child table creation
and isn't automatically retroactive when changed (see
reapply_privileges()). Unless you need direct access to the child
tables, this should not be needed. You can set the inherit_privileges
option if this is needed (see config table information below)."

And:

"reapply_privileges(
p_parent_table text
)
RETURNS void

This function is used to reapply ownership & grants on all child
tables based on what the parent table has set.
Privileges that the parent table has will be granted to all child
tables and privileges that the parent does not have will be revoked
(with CASCADE).
Privileges that are checked for are SELECT, INSERT, UPDATE, DELETE,
TRUNCATE, REFERENCES, & TRIGGER.
Be aware that for large partition sets, this can be a very long
running operation and is why it was made into a separate function to run
independently. Only privileges that are different between the parent &
child are applied, but it still has to do system catalog lookups and
comparisons for every single child partition and all individual
privileges on each.
p_parent_table - parent table of the partition set. Must be schema
qualified and match a parent table name already configured in pg_partman.
"

Thank you. I was not aware about this function which copies the grants from
parent to child ,so we can give a call to this function at the end of the
pg_partman job call which is happening through the cron job. But I see ,
the only issue is that this function only has one parameter
"p_parent_table" but nothing for "child_table" and that means it will try
to apply grants on all the childs/partitions which have been created till
today and may already be having the privileges already added in them.

And we have just ~60 partitions in most of the table so hope that will not
take longer but considering we create/purge one partition daily for each
partition table using the pg_partman, every time we give it a call, it will
try to apply/copy the grants on all the partitions(along with the current
day live partition), will it cause the existing running queries on the live
partitions to hard parse? or say will it cause any locking effect when it
will try to apply grant on the current/live partitions , which must be
inserted/updated/deleted data into or being queries by the users?

On 9/28/24 08:56, Lok P wrote:

On Sat, Sep 28, 2024 at 8:46 PM Adrian Klaver <adrian.klaver@aklaver.com
<mailto:adrian.klaver@aklaver.com>> wrote:

On 9/28/24 04:02, Lok P wrote:

Hi,
While we are creating any new tables, we used to give SELECT

privilege

on the newly created tables using the below command. But we are

seeing

now , in case of partitioned tables even if we had given the

privileges

in the same fashion, the user is not able to query specific

partitions

but only the table. Commands like "select * from
schema1.<partition_name> " are erroring out with the "insufficient
privilege" error , even if the partition belongs to the same table.

Grant SELECT ON <table_name> to <user_name>;

Grant was seen as a one time command which needed while creating the
table and then subsequent partition creation for that table was

handled

by the pg_partman extension. But that extension is not creating or
copying any grants on the table to the users. We were expecting ,

once

the base table is given a grant , all the inherited partitions

will be

automatically applied to those grants. but it seems it's not working
that way. So is there any other way to handle this situation?

The docs are there for a reason:

https://github.com/pgpartman/pg_partman/blob/master/doc/pg_partman.md#child-table-property-inheritance <https://github.com/pgpartman/pg_partman/blob/master/doc/pg_partman.md#child-table-property-inheritance&gt;

"Privileges & ownership are NOT inherited by default. If enabled by
pg_partman, note that this inheritance is only at child table creation
and isn't automatically retroactive when changed (see
reapply_privileges()). Unless you need direct access to the child
tables, this should not be needed. You can set the inherit_privileges
option if this is needed (see config table information below)."

And:

"reapply_privileges(
     p_parent_table text
)
RETURNS void

     This function is used to reapply ownership & grants on all child
tables based on what the parent table has set.
     Privileges that the parent table has will be granted to all child
tables and privileges that the parent does not have will be revoked
(with CASCADE).
     Privileges that are checked for are SELECT, INSERT, UPDATE,
DELETE,
TRUNCATE, REFERENCES, & TRIGGER.
     Be aware that for large partition sets, this can be a very long
running operation and is why it was made into a separate function to
run
independently. Only privileges that are different between the parent &
child are applied, but it still has to do system catalog lookups and
comparisons for every single child partition and all individual
privileges on each.
     p_parent_table - parent table of the partition set. Must be
schema
qualified and match a parent table name already configured in
pg_partman.
"

Thank you. I was not aware about this function which copies the grants
from parent to child ,so we can give a call to this function at the end
of the pg_partman job call which is happening through the cron job. But
I see , the only issue is that this function only has one parameter
"p_parent_table" but nothing for "child_table" and that means it will
try to apply grants on all the childs/partitions which have been created
till today and may already be having the privileges already added in them.

And we have just ~60 partitions in most of the table so hope that will
not take longer but considering we create/purge one partition daily for
each partition table using the pg_partman, every time we give it a call,
it will try to apply/copy the grants on all the partitions(along with
the current day live partition), will it cause the existing running
queries on the live partitions to hard parse? or say will it cause any
locking effect when it will try to apply grant on the current/live
partitions , which must be inserted/updated/deleted data into or being
queries by the users?

1) You seem to have missed the first part of the answer:

"Privileges & ownership are NOT inherited by default. If enabled by
pg_partman, note that this inheritance is only at child table creation
and isn't automatically retroactive when changed (see
reapply_privileges()). Unless you need direct access to the child
tables, this should not be needed. **You can set the
inherit_privileges** option if this is needed (see config table
information below)."

Read ** ...** part.

2) This is open source the code is available for you to see what is
actually going on:

https://github.com/pgpartman/pg_partman/blob/master/sql/functions/reapply_privileges.sql

which in turn uses:

https://github.com/pgpartman/pg_partman/blob/master/sql/functions/apply_privileges.sql

3) This is something that is easily tested on you end.

--
Adrian Klaver
adrian.klaver@aklaver.com