Re: [UNVERIFIED SENDER] Re: Challenges preventing us moving to 64 bit transaction id (XID)?

First 3 patches derived from the original 64-bit xid patch set by Alexander Korotkov

On 1/22/21, 5:42 PM, "Jim Finnerty" <jfinnert(at)amazon(dot)com> wrote:

I'll be uploading three patches (in a subsequent reply to this thread, so I
can do it via email):

- 64-bit integer GUCs
- Using ClogPageNumber and CLOG_PAGENO_FMT in places where clog pages are
currently declared as int or printed as a %d
- Using XID_FMT in places where xid's are printed with format %u, and
XID_BITS for one or two cases when we need to variant the code based on 32
or 64 bit xids.

These changes don't affect field sizes at all yet. They compile, build, and
run check-world cleanly.

64-bit GUCs were used in the original patch set to handle several
autovacuum_* gucs that needed to become 64-bit. This seems like a useful
thing to commit independent of what we do with xids.

The ClogPageNumber patch gives a name to the kind of page index that is
returned by TransactionIdToPage. The intent is to improve code clarity for
now. In the original patch it was modified from int to uint64.

In the original patch set xids were formatted using XID_FMT, and XID_FMT was
defined as INT64_FORMAT. This patch changes all the same places to XID_FMT
but keeps the current format string as %u, so it just cleans things up and
makes the code less sensitive to the assumption that xids are 32 bits.

...

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Jim Finnerty, AWS, Amazon Aurora PostgreSQL
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