On 28/11/2023 12:14, Pavel Borisov wrote:
On Tue, 28 Nov 2023 at 13:13, Heikki Linnakangas <hlinn...@iki.fi> wrote:
On 27/11/2023 01:43, Alexander Korotkov wrote:
v61 looks good to me. I'm going to push it as long as there are no objections.
This was discussed earlier, but is still present in v61:
+/*
+ * An internal function used by SlruScanDirectory().
+ *
+ * Returns true if a file with a name of a given length may be a correct
+ * SLRU segment.
+ */
+static inline bool
+SlruCorrectSegmentFilenameLength(SlruCtl ctl, size_t len)
+{
+ if (ctl->long_segment_names)
+ return (len == 15); /* see SlruFileName() */
+ else
+ /*
+ * Commit 638cf09e76d allowed 5-character lengths. Later commit
+ * 73c986adde5 allowed 6-character length.
+ *
+ * XXX should we still consider such names to be valid?
+ */
+ return (len == 4 || len == 5 || len == 6);
+}
+
I think it's pretty sloppy that the "short" filenames can be 4, 5 or 6
chars long. For pg_multixact/members, which introduced the 5-char case,
I think we should always pad the filenames 5 characters, and for
commit_ts which introduced the 6 char case, always pad to 6 characters.
Instead of a "long_segment_names" boolean, how about an integer field,
to specify the length.
That means that we'll need pg_upgrade to copy pg_multixact/members files
under the new names. That should be pretty straightforward.
I think what's done in patch 0001 is just an extension of existing
logic and moving it into separate function.
That's right. I'm arguing that now is a good time to clean it up.
I won't insist if Alexander prefers to commit it as it is, though. But
let's at least explain how this works in the comment, instead of the XXX.
--
Heikki Linnakangas
Neon (https://neon.tech)
