Horton

Re: making relfilenodes 56 bits

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Amul Sul <sulamul@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Andres Freund <andres@anarazel.de>, Heikki Linnakangas <hlinnaka@iki.fi>, Thomas Munro <thomas.munro@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-09-23T04:27:48Z
Lists: pgsql-hackers 
On Tue, Sep 20, 2022 at 7:46 PM Amul Sul <sulamul@gmail.com> wrote:
>

Thanks for the review

> Here are a few minor suggestions I came across while reading this
> patch, might be useful:
>
> +#ifdef USE_ASSERT_CHECKING
> +
> +   {
>
> Unnecessary space after USE_ASSERT_CHECKING.

Changed

>
> +               return InvalidRelFileNumber;    /* placate compiler */
>
> I don't think we needed this after the error on the latest branches.
> --

Changed

> +   LWLockAcquire(RelFileNumberGenLock, LW_SHARED);
> +   if (shutdown)
> +       checkPoint.nextRelFileNumber = ShmemVariableCache->nextRelFileNumber;
> +   else
> +       checkPoint.nextRelFileNumber = ShmemVariableCache->loggedRelFileNumber;
> +
> +   LWLockRelease(RelFileNumberGenLock);
>
> This is done for the good reason, I think, it should have a comment
> describing different checkPoint.nextRelFileNumber assignment
> need and crash recovery perspective.
> --

Done

> +#define SizeOfRelFileLocatorBackend \
> +   (offsetof(RelFileLocatorBackend, backend) + sizeof(BackendId))
>
> Can append empty parenthesis "()" to the macro name, to look like a
> function call at use or change the macro name to uppercase?
> --

Yeah we could SizeOfXXX macros are general practice I see used
everywhere in Postgres code so left as it is.

>  +   if (val < 0 || val > MAX_RELFILENUMBER)
> ..
>  if ((relfilenumber) < 0 || (relfilenumber) > MAX_RELFILENUMBER) \
>
> How about adding a macro for this condition as RelFileNumberIsValid()?
> We can replace all the checks referring to MAX_RELFILENUMBER with this.

Actually, RelFileNumberIsValid is used to just check whether it is
InvalidRelFileNumber value i.e. 0.  Maybe for this we can introduce
RelFileNumberInValidRange() but I am not sure whether it would be
cleaner than what we have now, so left as it is for now.


-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Fix typos in comments, code and documentation

  2. Increase width of RelFileNumbers from 32 bits to 56 bits.

  3. Move RelFileNumber declarations to common/relpath.h.

  4. Include RelFileLocator fields individually in BufferTag.

  5. Convert macros to static inline functions (buf_internals.h)

  6. Remove the restriction that the relmap must be 512 bytes.

  7. Change internal RelFileNode references to RelFileNumber or RelFileLocator.

  8. Reorder subskiplsn in pg_subscription to avoid alignment issues.

  9. Fix DROP {DATABASE,TABLESPACE} on Windows.

  10. Restructure smgr API as per recent proposal. smgr no longer depends on