Couple of issues with pg_xlogdump

Hello,

I was playing with pg_xlogdump in the HEAD and found a few issues.

1. Tried compiling pg_xlogdump via PGXS mechanism and it fails with the
following error:
make: *** No rule to make target
`/home/pavan.deolasee/work/pgsql/postgresql/install/lib/pgxs/src/makefiles/../../src/backend/access/transam/xlogreader.c',
needed by `xlogreader.c'. Stop.

There are no issues if the sources are compiled directly inside the contrib
module

2. I created a fresh database cluster, created a table and COPY IN a
million records in the table and then stopped the server. I then tried to
dump the xlog files from pg_xlog directory.

[pavan(dot)deolasee(at)puppetserver pg_xlogdump]$ ls ~/db93head/pg_xlog/
000000010000000000000004 000000010000000000000005
000000010000000000000006 000000010000000000000007
000000010000000000000008 archive_status

[pavan(dot)deolasee(at)puppetserver pg_xlogdump]$ ./pg_xlogdump
~/db93head/pg_xlog/000000010000000000000005
pg_xlogdump: FATAL: could not find a valid record after 0/5000000
[pavan(dot)deolasee(at)puppetserver pg_xlogdump]$ ./pg_xlogdump
~/db93head/pg_xlog/000000010000000000000006
pg_xlogdump: FATAL: could not find a valid record after 0/6000000
[pavan(dot)deolasee(at)puppetserver pg_xlogdump]$ ./pg_xlogdump
~/db93head/pg_xlog/000000010000000000000007
pg_xlogdump: FATAL: could not find a valid record after 0/7000000
[pavan(dot)deolasee(at)puppetserver pg_xlogdump]$ ./pg_xlogdump
~/db93head/pg_xlog/000000010000000000000008
pg_xlogdump: FATAL: could not find a valid record after 0/8000000

So pg_xlogdump gives error for all WAL files except the first one. Should
it not have printed the WAL records from these files ?

The first file prints ok with this at the end:

[pavan(dot)deolasee(at)puppetserver pg_xlogdump]$ ./pg_xlogdump
~/db93head/pg_xlog/000000010000000000000004 | tail -n 2
pg_xlogdump: FATAL: error in WAL record at 0/4C7F208: record with zero
length at 0/4C7F270

rmgr: XLOG len (rec/tot): 72/ 104, tx: 0, lsn:
0/04C7F1A0, prev 0/04C7F170, bkp: 0000, desc: checkpoint: redo 0/4400D70;
tli 1; prev tli 1; fpw true; xid 0/1807; oid 24576; multi 1; offset 0;
oldest xid 1795 in DB 1; oldest multi 1 in DB 1; oldest running xid 0;
online
rmgr: XLOG len (rec/tot): 72/ 104, tx: 0, lsn:
0/04C7F208, prev 0/04C7F1A0, bkp: 0000, desc: checkpoint: redo 0/4C7F208;
tli 1; prev tli 1; fpw true; xid 0/1807; oid 16387; multi 1; offset 0;
oldest xid 1795 in DB 1; oldest multi 1 in DB 1; oldest running xid 0;
shutdown

But even this is a bit surprising because I would have expected the
shutdown checkpoint WAL record in the last WAL file. Just to note, I
stopped the server only once at the end of loading the data.

I hope I am not doing something terribly wrong here.

3. The usage of pg_xlogdump shows this:
Usage:
pg_xlogdump [OPTION] [STARTSEG [ENDSEG]]

Looking at the usage, one might feel that the STARTSEG and ENDSEG both are
optional. But if I try to invoke pg_xlogdump without any argument, it fails.

Thanks,
Pavan

--
Pavan Deolasee
http://www.linkedin.com/in/pavandeolasee