Horton

Re: Table AM Interface Enhancements

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Andrei Lepikhov <a.lepikhov@postgrespro.ru>, Pavel Borisov <pashkin.elfe@gmail.com>, Japin Li <japinli@hotmail.com>, Mark Dilger <mark.dilger@enterprisedb.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-04-01T16:36:43Z
Lists: pgsql-hackers 
Coverity complained about what you did in RelationParseRelOptions
in c95c25f9a:

*** CID 1595992:  Null pointer dereferences  (FORWARD_NULL)
/srv/coverity/git/pgsql-git/postgresql/src/backend/utils/cache/relcache.c: 499 in RelationParseRelOptions()
493     
494     	/*
495     	 * Fetch reloptions from tuple; have to use a hardwired descriptor because
496     	 * we might not have any other for pg_class yet (consider executing this
497     	 * code for pg_class itself)
498     	 */
>>>     CID 1595992:  Null pointer dereferences  (FORWARD_NULL)
>>>     Passing null pointer "tableam" to "extractRelOptions", which dereferences it.
499     	options = extractRelOptions(tuple, GetPgClassDescriptor(),
500     								tableam, amoptsfn);
501     

I see that extractRelOptions only uses the tableam argument for some
relkinds, and RelationParseRelOptions does set it up for those
relkinds --- but Coverity's complaint isn't without merit, because
those two switch statements are looking at *different copies of the
relkind*, which in theory could be different.  This all seems quite
messy and poorly factored.  Can't we do better?  Why do we need to
involve two copies of allegedly the same pg_class tuple, anyhow?

			regards, tom lane

Commits

  1. Remove extra comment at TableAmRoutine.scan_analyze_next_block

  2. revert: Generalize relation analyze in table AM interface

  3. Revert: Allow table AM to store complex data structures in rd_amcache

  4. Revert: Allow table AM tuple_insert() method to return the different slot

  5. Revert: Allow locking updated tuples in tuple_update() and tuple_delete()

  6. Revert: Let table AM insertion methods control index insertion

  7. Revert: Custom reloptions for table AM

  8. Provide a way block-level table AMs could re-use acquire_sample_rows()

  9. Custom reloptions for table AM

  10. Use streaming I/O in ANALYZE.

  11. Revert "Custom reloptions for table AM"

  12. Let table AM insertion methods control index insertion

  13. Generalize relation analyze in table AM interface

  14. Improve error message for tts_(virtual|minimal)_is_current_xact_tuple

  15. Add comments on some MinimalTupleSlots methods usage

  16. Add TupleTableSlotOps.is_current_xact_tuple() method

  17. Allow table AM tuple_insert() method to return the different slot

  18. Allow table AM to store complex data structures in rd_amcache