Re: WAL usage calculation patch

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>

To: Julien Rouhaud <rjuju123@gmail.com>

Cc: Kuntal Ghosh <kuntalghosh.2007@gmail.com>, Fujii Masao <masao.fujii@oss.nttdata.com>, Kirill Bychik <kirill.bychik@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Thomas Munro <thomas.munro@gmail.com>

Date: 2020-04-01T11:30:59Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Change the display of WAL usage statistics in Explain.
- 69bfaf2e1de4 13.0 landed
Cosmetic fixups for WAL usage work.
- ef08ca113fe3 13.0 landed
Allow parallel create index to accumulate buffer usage stats.
- 5c71362174eb 13.0 landed
- f179e9f01b65 11.8 landed
- 13823ad3b012 12.3 landed
Allow autovacuum to log WAL usage statistics.
- b7ce6de93b59 13.0 landed
Add the option to report WAL usage in EXPLAIN and auto_explain.
- 33e05f89c53e 13.0 landed
Allow pg_stat_statements to track WAL usage statistics.
- 6b466bf5f2be 13.0 landed
Add infrastructure to track WAL usage.
- df3b181499b4 13.0 landed
Include information on buffer usage during planning phase, in EXPLAIN output, take two.
- ce77abe63cfc 13.0 cited
Include information on buffer usage during planning phase, in EXPLAIN output.
- ed7a5095716e 13.0 cited
Allow parallel vacuum to accumulate buffer usage.
- 3a5e22138a8d 13.0 landed
Allow pg_stat_statements to track planning statistics.
- 17e03282241c 13.0 cited

On Wed, Apr 1, 2020 at 4:29 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> v9-0005-Keep-track-of-WAL-usage-in-pg_stat_statements
>

One more comment related to this patch.
+
+ snprintf(buf, sizeof buf, UINT64_FORMAT, tmp.wal_bytes);
+
+ /* Convert to numeric. */
+ wal_bytes = DirectFunctionCall3(numeric_in,
+ CStringGetDatum(buf),
+ ObjectIdGetDatum(0),
+ Int32GetDatum(-1));
+
+ values[i++] = wal_bytes;

I see that other places that display uint64 values use BIGINT datatype
in SQL, so why can't we do the same here?  See the usage of queryid in
pg_stat_statements or internal_pages, *_pages exposed via
pgstatindex.c.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com