Re: Exposing the stats snapshot timestamp to SQL

Robert, I'll add it to the commitfest.

Jim, I'm not sure I understand what you mean?  This new function follows the same conventions as everything else in the file.  TimestampTz is just a typedef for int64.  Functions like pg_stat_get_buf_alloc follow the exact same pattern on the int64 fields of the global stats struct.

- Matt K.

On Thu, Jan 29, 2015 at 6:49 PM, Jim Nasby <Jim.Nasby@bluetreble.com> wrote:

On 1/28/15 11:18 PM, Matt Kelly wrote:

In a previous thread Tom Lane said:

    (I'm also wondering if it'd make sense to expose the stats timestamp
    as a callable function, so that the case could be dealt with
    programmatically as well.  But that's future-feature territory.)

(http://www.postgresql.org/message-id/27251.1421684169@sss.pgh.pa.us)

It seemed the appropriate scope for my first submission, and that feature has been on my wish list for a while, so I thought I'd grab it.

I've reviewed the patch (though haven't tested it myself) and it looks good. The only thing I'm not sure of is this:

+ /* Get the timestamp of the current statistics snapshot */
+ Datum
+ pg_stat_snapshot_timestamp(PG_FUNCTION_ARGS)
+ {
+       PG_RETURN_TIMESTAMPTZ(pgstat_fetch_global()->stats_timestamp);
+ }

Is the community OK with referencing stats_timestamp that way?
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com