existing lock manager and spinlocks: it understands exclusive vs shared
lock but has few other fancy features. Replace most uses of spinlocks
with lightweight locks. All remaining uses of spinlocks have very short
lock hold times (a few dozen instructions), so tweak spinlock backoff
code to work efficiently given this assumption. All per my proposal on
pghackers 26-Sep-01.
Assign the fixed user id 1 to the user created by initdb.
A stand-alone backend will always set the user id to 1.
(Consequently, the name of that user is no longer important.)
In stand-alone mode, the user id 1 will have implicit superuser
status, to allow repairs even if there are no users defined.
Print a warning message when starting in stand-alone mode when no
users are defined.
Disallow dropping the current user and session user.
Granting/revoking superuser status also grants/revokes usecatupd.
(Previously, it would never grant it back. This could lead to "deadlocks".)
CREATE USER and CREATE GROUP will start allocating user ids at 100
(unless explicitly specified), to prevent accidental creation of a
superuser (plus some room for future extensions).
for them, and making them just wastes time during backend startup/shutdown.
Also, remove compile-time MAXBACKENDS limit per long-ago proposal.
You can now set MaxBackends as high as your kernel can stand without
any reconfiguration/recompilation.
-------------------------------------------------------------------
Subject: Re: [PATCHES] encoding names
From: Karel Zak <zakkr@zf.jcu.cz>
To: Peter Eisentraut <peter_e@gmx.net>
Cc: pgsql-patches <pgsql-patches@postgresql.org>
Date: Fri, 31 Aug 2001 17:24:38 +0200
On Thu, Aug 30, 2001 at 01:30:40AM +0200, Peter Eisentraut wrote:
> > - convert encoding 'name' to 'id'
>
> I thought we decided not to add functions returning "new" names until we
> know exactly what the new names should be, and pending schema
Ok, the patch not to add functions.
> better
>
> ...(): encoding name too long
Fixed.
I found new bug in command/variable.c in parse_client_encoding(), nobody
probably never see this error:
if (pg_set_client_encoding(encoding))
{
elog(ERROR, "Conversion between %s and %s is not supported",
value, GetDatabaseEncodingName());
}
because pg_set_client_encoding() returns -1 for error and 0 as true.
It's fixed too.
IMHO it can be apply.
Karel
PS:
* following files are renamed:
src/utils/mb/Unicode/KOI8_to_utf8.map -->
src/utils/mb/Unicode/koi8r_to_utf8.map
src/utils/mb/Unicode/WIN_to_utf8.map -->
src/utils/mb/Unicode/win1251_to_utf8.map
src/utils/mb/Unicode/utf8_to_KOI8.map -->
src/utils/mb/Unicode/utf8_to_koi8r.map
src/utils/mb/Unicode/utf8_to_WIN.map -->
src/utils/mb/Unicode/utf8_to_win1251.map
* new file:
src/utils/mb/encname.c
* removed file:
src/utils/mb/common.c
--
Karel Zak <zakkr@zf.jcu.cz>
http://home.zf.jcu.cz/~zakkr/
C, PostgreSQL, PHP, WWW, http://docs.linux.cz, http://mape.jcu.cz
buffer manager with 'pg_clog', a specialized access method modeled
on pg_xlog. This simplifies startup (don't need to play games to
open pg_log; among other things, OverrideTransactionSystem goes away),
should improve performance a little, and opens the door to recycling
commit log space by removing no-longer-needed segments of the commit
log. Actual recycling is not there yet, but I felt I should commit
this part separately since it'd still be useful if we chose not to
do transaction ID wraparound.
detected sooner in backend startup, and is treated as an expected error
(it gives 'Sorry, too many clients already' now). This allows us not
to have to enforce the MaxBackends limit exactly in the postmaster.
Also, remove ProcRemove() and fold its functionality into ProcKill().
There's no good reason for a backend not to be responsible for removing
its PROC entry, and there are lots of good reasons for the postmaster
not to be touching shared-memory data structures.
are now critical sections, so as to ensure die() won't interrupt us while
we are munging shared-memory data structures. Avoid insecure intermediate
states in some code that proc_exit will call, like palloc/pfree. Rename
START/END_CRIT_CODE to START/END_CRIT_SECTION, since that seems to be
what people tend to call them anyway, and make them be called with () like
a function call, in hopes of not confusing pg_indent.
I doubt that this is sufficient to make SIGTERM safe anywhere; there's
just too much code that could get invoked during proc_exit().
to ensure that we have released buffer refcounts and so forth, rather than
putting ad-hoc operations before (some of the calls to) proc_exit. Add
commentary to discourage future hackers from repeating that mistake.
IPC key assignment will now work correctly even when multiple postmasters
are using same logical port number (which is possible given -k switch).
There is only one shared-mem segment per postmaster now, not 3.
Rip out broken code for non-TAS case in bufmgr and xlog, substitute a
complete S_LOCK emulation using semaphores in spin.c. TAS and non-TAS
logic is now exactly the same.
When deadlock is detected, "Deadlock detected" is now the elog(ERROR)
message, rather than a NOTICE that comes out before an unhelpful ERROR.
maintained for each cache entry. A cache entry will not be freed until
the matching ReleaseSysCache call has been executed. This eliminates
worries about cache entries getting dropped while still in use. See
my posting to pg-hackers of even date for more info.
cloned, rather than always cloning template1. Modify initdb to generate
two identical databases rather than one, template0 and template1.
Connections to template0 are disallowed, so that it will always remain
in its virgin as-initdb'd state. pg_dumpall now dumps databases with
restore commands that say CREATE DATABASE foo WITH TEMPLATE = template0.
This allows proper behavior when there is user-added data in template1.
initdb forced!
that search loops only have to scan that far and not through all maxBackends
entries. This eliminates a performance penalty for setting maxBackends
much higher than the average number of active backends. Also, eliminate
no-longer-used 'backend tag' concept. Remove setting of environment
variables at backend start (except for CYR_RECODE), since none of them
are being examined by the backend any longer.
There is still no effective difference but it will kick in once setuid
functions exist (not included here). Make old getpgusername() alias for
current_user.
user is now defined in terms of the user id, the user name is only computed
upon request (for display purposes). This is kind of the opposite of the
previous state, which would maintain the user name and compute the user id
for permission checks.
Besides perhaps saving a few cycles (integer vs string), this now creates a
single point of attack for changing the user id during a connection, for
purposes of "setuid" functions, etc.
that giving pg_proc a toast table required solving the same problems
we'd have to solve for pg_class --- pg_proc is one of the relations
that gets bootstrapped in relcache.c. Solution is to go back at the
end of initialization and read in the *real* pg_class row to replace
the phony entry created by formrdesc(). This should work as long as
there's no need to touch any toasted values during initialization,
which seems a reasonable assumption.
Although I did not add a toast-table for every single system table
with a varlena attribute, I believe that it would work to just do
ALTER TABLE pg_class CREATE TOAST TABLE. So anyone who's really
intent on having several thousand ACL entries for a rel could do it.
NOTE: I didn't force initdb, but you must do one to see the effects
of this patch.
backend functions via backend PQexec(). The SPI interface has long
been our only documented way to do this, and the backend pqexec/portal
code is unused and suffering bit-rot. I'm putting it out of its misery.
and config.h. Adjusted all referring code.
Scrapped pg_version and changed initdb accordingly. Integrated
src/utils/version.c into src/backend/utils/init/miscinit.c. Changed all
callers.
Set version number to `7.1devel'. (Non-numeric version suffixes now allowed.)
for details). It doesn't really do that much yet, since there are no
short-term memory contexts in the executor, but the infrastructure is
in place and long-term contexts are handled reasonably. A few long-
standing bugs have been fixed, such as 'VACUUM; anything' in a single
query string crashing. Also, out-of-memory is now considered a
recoverable ERROR, not FATAL.
Eliminate a large amount of crufty, now-dead code in and around
memory management.
Fix problem with holding off SIGTRAP, SIGSEGV, etc in postmaster and
backend startup.
key call sites are changed, but most called functions are still oldstyle.
An exception is that the PL managers are updated (so, for example, NULL
handling now behaves as expected in plperl and plpgsql functions).
NOTE initdb is forced due to added column in pg_proc.
inval.c thought it could safely use the catcache to look up the OIDs of
system relations. Not good, considering that inval.c could be called
during catcache loading, if a shared-inval message arrives. Rip out the
lookup logic and instead use the known OIDs from pg_class.h.
eliminating some wildly inconsistent coding in various parts of the
system. I set MAXPGPATH = 1024 in config.h.in. If anyone is really
convinced that there ought to be a configure-time test to set the
value, go right ahead ... but I think it's a waste of time.
* Buffer refcount cleanup (per my "progress report" to pghackers, 9/22).
* Add links to backend PROC structs to sinval's array of per-backend info,
and use these links for routines that need to check the state of all
backends (rather than the slow, complicated search of the ShmemIndex
hashtable that was used before). Add databaseOID to PROC structs.
* Use this to implement an interlock that prevents DESTROY DATABASE of
a database containing running backends. (It's a little tricky to prevent
a concurrently-starting backend from getting in there, since the new
backend is not able to lock anything at the time it tries to look up
its database in pg_database. My solution is to recheck that the DB is
OK at the end of InitPostgres. It may not be a 100% solution, but it's
a lot better than no interlock at all...)
* In ALTER TABLE RENAME, flush buffers for the relation before doing the
rename of the physical files, to ensure we don't get failures later from
mdblindwrt().
* Update TRUNCATE patch so that it actually compiles against current
sources :-(.
You should do "make clean all" after pulling these changes.
