anywhere from zero to two TODO items.
* Allow flag to control COPY input/output of NULLs
I got this:
COPY table .... [ WITH NULL AS 'string' ]
which does what you'd expect. The default is \N, otherwise you can use
empty strings, etc. On Copy In this acts like a filter: every data item
that looks like 'string' becomes a NULL. Pretty straightforward.
This also seems to be related to
* Make postgres user have a password by default
If I recall this discussion correctly, the problem was actually that the
default password for the postgres (or any) user is in fact "\N", because
of the way copy is used. With this change, the file pg_pwd is copied out
with nulls as empty strings, so if someone doesn't have a password, the
password is just '', which one would expect from a new account. I don't
think anyone really wants a hard-coded default password.
Peter Eisentraut Sernanders väg 10:115
* Document/trigger/rule so changes to pg_shadow recreate pg_pwd
I did it with a trigger and it seems to work like a charm. The function
that already updates the file for create and alter user has been made a
built-in "SQL" function and a trigger is created at initdb time.
Comments around the pg_pwd updating function seem to be worried about
this
routine being called concurrently, but I really don't see a reason to
worry about this. Verify for yourself. I guess we never had a system
trigger before, so treat this with care, and feel free to adjust the
nomenclature as well.
--
Peter Eisentraut Sernanders väg 10:115
at all, and because of shell quoting rules this can't be fixed, so I put
in error messages to that end.
Also, calling create or drop database in a transaction block is not so
good either, because the file system mysteriously refuses to roll back rm
calls on transaction aborts. :) So I put in checks to see if a transaction
is in progress and signal an error.
Also I put the whole call in a transaction of its own to be able to roll
back changes to pg_database in case the file system operations fail.
The alternative location issues I posted recently were untouched, awaiting
the outcome of that discussion. Other than that, this should be much more
fool-proof now.
The docs I cleaned up as well.
Peter Eisentraut Sernanders väg 10:115
yet, but at least we can give a better error message:
regression=> select count(distinct f1) from int4_tbl;
ERROR: aggregate(DISTINCT ...) is not implemented yet
instead of 'parser: parse error at or near distinct'.
I was able to crash postgres 6.5.3 when I did an 'alter user' command.
After I started a debugger I found the problem in the timezone handling
of
datetime (my Linux box lost its timezone information, that's how the
problem occurred).
Only 7 bytes are reserved for the timezone, without checking for
boundaries.
Attached is a patch that fixes this problem and emits a NOTICE if a
timezone is encountered that is longer than MAXTZLEN bytes, like this:
Jeroen van Vianen
(which are palloc'd) instead of DLLists (which are malloc'd). Not very
significant, since this routine seldom has anything useful to do, but
a leak is a leak...
This one should work much better than the one I sent in previously. The
functionality is the same, but the patch was missing one file resulting
in
the compilation failing. The docs also received a minor fix.
Peter Eisentraut Sernanders väg 10:115
table owner in order to vacuum a table. This is mainly to prevent
denial-of-service attacks via repeated vacuums. Allow VACUUM to gather
statistics about system relations, except for pg_statistic itself ---
not clear that it's worth the trouble to make that case work cleanly.
Cope with possible tuple size overflow in pg_statistic tuples; I'm
surprised we never realized that could happen. Hold a couple of locks
a little longer to try to prevent deadlocks between concurrent VACUUMs.
There still seem to be some problems in that last area though :-(
parallel --- and, not incidentally, removing a common reason for needing
manual cleanup by the DB admin after a crash. Remove initial global
delete of pg_statistics rows in VACUUM ANALYZE; this was not only bad
for performance of other backends that had to run without stats for a
while, but it was fundamentally broken because it was done outside any
transaction. Surprising we didn't see more consequences of that.
Detect attempt to run VACUUM inside a transaction block. Check for
query cancel request before starting vacuum of each table. Clean up
vacuum's private portal storage if vacuum is aborted.
By dropping stats rows here, we eliminate the need for VACUUM to do a
wholesale remove of stats rows. Before, pg_statistics was wiped clean
at the start of VACUUM, ensuring poor planning results for any backends
running in parallel until VACUUM got around to rebuilding the stats for
the relations they are accessing.
Make all system indexes unique.
Make all cache loads use system indexes.
Rename *rel to *relid in inheritance tables.
Rename cache names to be clearer.
