Avoid checking permission of Babelfish temp tables on parallel worker #560
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kuntalghosh
requested changes
Apr 3, 2025
|
Just curious how parallel workers fetches other details for temp tables relations after permission check ? It must need more information about the relation while executing the node with temp table. |
2jungkook
reviewed
Apr 3, 2025
Postgres code is written in a way that it will throw an error if any kind of access made to temp table under parallel operations. If we are concerned with operation metadata then it would be already calculated by leader node. Parallel worker just init the plan and pass it to executor run. Do you have any specific example that we should try? |
Deepesh125
changed the title
src/backend/executor/execMain.c
Outdated
| * chance to skip permission check for such use cases. | ||
| */ | ||
| if (IsBabelfishParallelWorker() && | ||
| ExecCheckOneRelPerms_hook && |
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can we put extension hook check first to be more safe
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what difference will it make?
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Shouldn't the parallel worker check be in the extension?
added 2 commits
April 8, 2025 12:33
kuntalghosh
reviewed
Apr 9, 2025
src/backend/executor/execMain.c
Outdated
| * chance to skip permission check for such use cases. | ||
| */ | ||
| if (IsBabelfishParallelWorker() && | ||
| ExecCheckOneRelPerms_hook && |
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Shouldn't the parallel worker check be in the extension?
surendravishnoi
approved these changes
Apr 9, 2025
kuntalghosh
approved these changes
Apr 10, 2025
Deepesh125
merged commit 5e62ffa
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babelfish-for-postgresql:BABEL_5_X_DEV__PG_17_X
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Deepesh125
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…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)
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Apr 10, 2025
…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)
Deepesh125
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Apr 10, 2025
…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)
Deepesh125
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Apr 10, 2025
…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)
Deepesh125
added a commit
to amazon-aurora/postgresql_modified_for_babelfish
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this pull request
Apr 10, 2025
…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)
Deepesh125
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Apr 13, 2025
…l worker (babelfish-for-postgresql#560)" This reverts commit 4cd4eb8.
Deepesh125
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Apr 14, 2025
…#560) (#567) 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)
Deepesh125
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Apr 14, 2025
…#560) (#566) 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)
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Description
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.
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.
Issues Resolved
BABEL-5703
Check List
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