Re: standby recovery fails (tablespace related) (tentative patch and discussion)

I had a look at this latest version of the patch, and found some things
to tweak. Attached is v21 with three main changes from Kyotaro's v20:

1. the XLogFlush is only done if consistent state has not been reached.
As I understand, it's not needed in normal mode. (In any case, if we do
call XLogFlush in normal mode, what it does is not advance the recovery
point, so the comment would be incorrect.)

2. use %u to print OIDs rather than %d

3. I changed the warning message wording to this:

+ ereport(WARNING,
+ (errmsg("skipping replay of database creation WAL record"),
+ errdetail("The source database directory \"%s\" was not found.",
+ src_path),
+ errhint("A future WAL record that removes the directory before reaching consistent mode is expected.")));

I also renamed the function XLogReportMissingDir to
XLogRememberMissingDir (which matches the "forget" part) and changed the
DEBUG2 messages in that function to DEBUG1 (all the calls in other
functions remain DEBUG2, because ISTM they are not as interesting).
Finally, I made the TAP test search the WARNING line in the log.

--
Álvaro Herrera 48°01'N 7°57'E — https://www.EnterpriseDB.com/
"No tengo por qué estar de acuerdo con lo que pienso"
(Carlos Caszeli)