Skip to content

Avoid checking permission of Babelfish temp tables on parallel worker #570

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Conversation

Deepesh125
Copy link
Contributor

Consider following facts,

  1. Babelfish temp tables are implemented using ENR which is not shared between different backends. So if Parallel worker tries to check permissions on Babelfish then it will fail.
  2. Any user should be able to access Babelfish temp tables under given session.
  3. Postgres by default does not allow parallel operations on temp tables. Attempt to do so will result in run time error.

Due to above facts, we should avoid permission check on temp tables within parallel workers while ensuring that leader does required permission check on other tables. This commits achieves this behaviour by introducing following three hooks,

ParallelQueryMain_hook -- Hook that allows other extensions to pass on additional details from Leader node to parallel worker. For example, Babelfish extension can pass details of Babelfish temp table defined under current session with Parallel workers.

ExecInitParallelPlan_hook -- Hook that allows Parallel worker to gather additional details passed by Leader node. For example, Babelfish extension can collect the details of Babelfish temp table shared by Leader node so that it can avoid permission checks.

ExecCheckRTEPerms_hook -- Hook that allows extension control permission checking on given relation/table. For example, Babelfish can use it to avoid permission check on temp tables under parallel worker.

Task: BABEL-5703
Signed-off-by: Dipesh Dhameliya [email protected]
(cherry picked from commit 5e62ffa)

  • Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is under the terms of the PostgreSQL license, and grant any person obtaining a copy of the contribution permission to relicense all or a portion of my contribution to the PostgreSQL License solely to contribute all or a portion of my contribution to the PostgreSQL open source project.

For more information on following Developer Certificate of Origin and signing off your commits, please check here.

Deepesh125 and others added 3 commits April 10, 2025 09:27
…babelfish-for-postgresql#560)

Consider following facts,

1. Babelfish temp tables are implemented using ENR which is not shared between different backends. So if Parallel
worker tries to check permissions on Babelfish then it will fail.
2. Any user should be able to access Babelfish temp tables under given session.
3. Postgres by default does not allow parallel operations on temp tables. Attempt to do so will result in run time error.

Due to above facts, we should avoid permission check on temp tables within parallel workers while ensuring that leader
does required permission check on other tables. This commits achieves this behaviour by introducing following three
hooks,

ParallelQueryMain_hook -- Hook that allows other extensions to pass on additional details from Leader node to
parallel worker. For example, Babelfish extension can pass details of Babelfish temp table defined under current
session with Parallel workers.

ExecInitParallelPlan_hook -- Hook that allows Parallel worker to gather additional details passed by Leader node.
For example, Babelfish extension can collect the details of Babelfish temp table shared by Leader node so that it
can avoid permission checks.

ExecCheckOneRelPerms_hook -- Hook that allows extension control permission checking on given relation/table.
For example, Babelfish can use it to avoid permission check on temp tables under parallel worker.

Task: BABEL-5703
Signed-off-by: Dipesh Dhameliya <[email protected]>
(cherry picked from commit 5e62ffa)
…babelfish-for-postgresql#569)

Consider following facts,

Babelfish temp tables are implemented using ENR which is not shared between different backends. So if Parallel worker tries to check permissions on Babelfish then it will fail.
Any user should be able to access Babelfish temp tables under given session.
Postgres by default does not allow parallel operations on temp tables. Attempt to do so will result in run time error.
Due to above facts, we should avoid permission check on temp tables within parallel workers while ensuring that leader does required permission check on other tables. This commits achieves this behaviour by introducing following three hooks,

ParallelQueryMain_hook -- Hook that allows other extensions to pass on additional details from Leader node to parallel worker. For example, Babelfish extension can pass details of Babelfish temp table defined under current session with Parallel workers.

ExecInitParallelPlan_hook -- Hook that allows Parallel worker to gather additional details passed by Leader node. For example, Babelfish extension can collect the details of Babelfish temp table shared by Leader node so that it can avoid permission checks.

ExecCheckRTEPerms_hook -- Hook that allows extension control permission checking on given relation/table. For example, Babelfish can use it to avoid permission check on temp tables under parallel worker.

Also, this changes introduces stringToBms(...) API using which we can directly build Bitmapset from given string. This is
especially useful by Babelfish parallel worker to prepare Bitmapset of temp relids from string shared by Leader node.

Task: BABEL-5703
Signed-off-by: Dipesh Dhameliya <[email protected]>
Copy link

@jsudrik jsudrik left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Approved.

@Deepesh125 Deepesh125 merged commit fa391af into babelfish-for-postgresql:BABEL_2_X_DEV__PG_14_X Apr 14, 2025
1 check passed
@Deepesh125 Deepesh125 deleted the jira-babel-5703-2-X branch April 14, 2025 08:34
Deepesh125 added a commit to amazon-aurora/postgresql_modified_for_babelfish that referenced this pull request Apr 14, 2025
…babelfish-for-postgresql#570)

Consider following facts,

Babelfish temp tables are implemented using ENR which is not shared between different backends. So if Parallel
worker tries to check permissions on Babelfish then it will fail.

Any user should be able to access Babelfish temp tables under given session.
Postgres by default does not allow parallel operations on temp tables. Attempt to do so will result in run time error.

Due to above facts, we should avoid permission check on temp tables within parallel workers while ensuring that
leader does required permission check on other tables. This commits achieves this behaviour by introducing following
three hooks,

ParallelQueryMain_hook -- Hook that allows other extensions to pass on additional details from Leader node to parallel
worker. For example, Babelfish extension can pass details of Babelfish temp table defined under current session with
Parallel workers.

ExecInitParallelPlan_hook -- Hook that allows Parallel worker to gather additional details passed by Leader node. For
example, Babelfish extension can collect the details of Babelfish temp table shared by Leader node so that it can avoid
permission checks.

ExecCheckRTEPerms_hook -- Hook that allows extension control permission checking on given relation/table. For
example, Babelfish can use it to avoid permission check on temp tables under parallel worker.

Also, this changes introduces stringToBms(...) API using which we can directly build Bitmapset from given string. This
is especially useful by Babelfish parallel worker to prepare Bitmapset of temp relids from string shared by Leader
node.

Task: BABEL-5703
Signed-off-by: Dipesh Dhameliya <[email protected]>
(cherry picked from commit 7199fa7)
(cherry picked from commit fa391af)
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

2 participants