Avoid checking permission of Babelfish temp tables on parallel worker #569

Deepesh125 · 2025-04-10T06:46:11Z

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]

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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)

…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]>

…#569) (#571) 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]>

surendravishnoi previously approved these changes Apr 10, 2025

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Add support to prepare Bitmapset directly from String

4574947

Deepesh125 dismissed surendravishnoi’s stale review via 4574947 April 11, 2025 06:24

surendravishnoi approved these changes Apr 11, 2025

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Deepesh125 merged commit 7199fa7 into babelfish-for-postgresql:BABEL_3_X_DEV__PG_15_X Apr 11, 2025
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Deepesh125 deleted the jira-babel-5703-3-X branch April 11, 2025 14:36

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Avoid checking permission of Babelfish temp tables on parallel worker #569

Avoid checking permission of Babelfish temp tables on parallel worker #569

Deepesh125 commented Apr 10, 2025 •

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Avoid checking permission of Babelfish temp tables on parallel worker #569

Avoid checking permission of Babelfish temp tables on parallel worker #569

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Deepesh125 commented Apr 10, 2025 •

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