Re: [HACKERS] PostgreSQL-R

2002-12-23 Thread Vadim Mikheev
> > It seems that locking tuples via LockTable at Phase 1 is not > > required anymore, right? > > We haven't put those hooks in yet, so the current version is master/slave. So, you are not going to use any LockTable in Phase 1 on master right now but you still need some LockTable in Phase 3 on sla

[HACKERS] Vacation

2002-12-26 Thread Vadim Mikheev
I'll be on vacation from 12/27/02 till 01/20/03. Vadim ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org

[HACKERS] Vacation

2003-01-02 Thread Vadim Mikheev
I'll be on vacation from 12/27/02 till 01/20/03. Vadim ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])

Re: [HACKERS] RE: [BUGS] Loosing files after backend crash

2001-04-05 Thread Vadim Mikheev
> > FATAL 2: XLogWrite: write request is past end of log" to syslog. Ok, I hope this one is fixed. Tom, please review changes. Konstantin, are you able to compile PG from CVS? To restart postmaster with current version... Vadim ---(end of broadcast)---

Re: [HACKERS] 7.1 startup recovery failure

2001-04-26 Thread Vadim Mikheev
> There's a report of startup recovery failure in Japan. > Redo done but ... > Unfortunately I have no time today. Please ask to start up with wal_debug = 1... Vadim ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unreg

[HACKERS] Re: [BUGS] Postgres bug (working with iserverd)

2001-05-14 Thread Vadim Mikheev
> However, EvalPlanQual still leaks more memory than suits me --- > auxiliary memory allocated by the plan nodes is not recovered. > I think the correct way to implement it would be to create a new > memory context for each level of EvalPlanQual execution and use > that context as the "per-query c

[HACKERS] Re: [BUGS] Postgres bug (working with iserverd)

2001-05-14 Thread Vadim Mikheev
> > How subselects run queries again and again? > > They don't end and restart them; they just rescan them. If we had Thanks for recollection. > this substitute-a-new-tuple hack integrated into the Param mechanism, > then EvalPlanQual could use ExecReScan too, but at the moment no... I see.

Re: [HACKERS] Plans for solving the VACUUM problem

2001-05-19 Thread Vadim Mikheev
> Hm. On the other hand, relying on WAL for undo means you cannot drop > old WAL segments that contain records for any open transaction. We've > already seen several complaints that the WAL logs grow unmanageably huge > when there is a long-running transaction, and I think we'll see a lot > more

Re: [HACKERS] Plans for solving the VACUUM problem

2001-05-20 Thread Vadim Mikheev
> >> 1. Space reclamation via UNDO doesn't excite me a whole lot, if we can > >> make lightweight VACUUM work well. > > > Sorry, but I'm going to consider background vacuum as temporary solution > > only. As I've already pointed, original PG authors finally became > > disillusioned with the same

Re: [HACKERS] Plans for solving the VACUUM problem

2001-05-20 Thread Vadim Mikheev
> Were you going to use WAL to get free space from old copies too? Considerable approach. > Vadim, I think I am missing something. You mentioned UNDO would be used > for these cases and I don't understand the purpose of adding what would > seem to be a pretty complex capability: Yeh, we alread

Re: [HACKERS] Plans for solving the VACUUM problem

2001-05-20 Thread Vadim Mikheev
> > Really?! Once again: WAL records give you *physical* address of tuples > > (both heap and index ones!) to be removed and size of log to read > > records from is not comparable with size of data files. > > You sure? With our current approach of dumping data pages into the WAL > on first chang

Re: [HACKERS] Plans for solving the VACUUM problem

2001-05-20 Thread Vadim Mikheev
> If its an "experiment", shouldn't it be done outside of the main source > tree, with adequate testing in a high load situation, with a patch > released to the community for further testing/comments, before it is added > to the source tree? From reading Vadim's comment above (re: > pre-Postgres9

Re: [HACKERS] Plans for solving the VACUUM problem

2001-05-20 Thread Vadim Mikheev
> Seriously, I don't think that my proposed changes need be treated with > quite that much suspicion. The only part that is really intrusive is Agreed. I fight for UNDO, not against background vacuum -:) > the shared-memory free-heap-space-management change. But AFAICT that > will be a necessa

Re: [HACKERS] Plans for solving the VACUUM problem

2001-05-28 Thread Vadim Mikheev
> Yes, that is a good description. And old version is only required in the following > two cases: > > 1. the txn that modified this tuple is still open (reader in default committed read) > 2. reader is in serializable transaction isolation and has earlier xtid > > Seems overwrite smgr has mainl

Re: AW: [HACKERS] Plans for solving the VACUUM problem

2001-05-28 Thread Vadim Mikheev
> > > > You mean it is restored in session that is running the transaction ? > > > > Depends on what you mean with restored. It first reads the heap page, > > sees that it needs an older version and thus reads it from the "rollback segment". > > So are whole pages stored in rollback segments or

[HACKERS] Now it's my turn...

2001-06-29 Thread Vadim Mikheev
Baby girl on Jun 27. Vadim ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html

[HACKERS] Re: Strangeness in xid allocation / snapshot setup

2001-07-12 Thread Vadim Mikheev
> > 1. Tx Old is running. > > 2. Tx S reads new transaction ID in GetSnapshotData() and swapped away > >before SInval acquired. > > 3. Tx New gets new transaction ID, makes changes and commits. > > 4. Tx Old changes some row R changed by Tx New and commits. > > 5. Tx S gets snapshot data and n

RE: [HACKERS] User locks code

2001-08-19 Thread Vadim Mikheev
Well, ability to lock only unlocked rows in select for update is useful, of course. But uniq features of user'locks are: 1. They don't interfere with normal locks hold by session/transaction. 2. Share lock is available. 3. User can lock *and unlock objects* inside transaction, which is not (a

Re: [HACKERS] Status of index location patch

2001-09-14 Thread Vadim Mikheev
> Just wondering what is the status of this patch. Is seems from comments > that people like the idea. I have also looked in the archives for other > people looking for this kind of feature and have found alot of interest. > > If you think it is a good idea for 7.2, let me know what needs to be

Re: [HACKERS] Status of index location patch

2001-09-15 Thread Vadim Mikheev
> Can you explain how I would get the tblNode for an existing database > index files if it doesn't have the same OID as the database entry in > pg_databases. Well, keeping in mind future tablespace implementation I would add tblNode to pg_class and in pg_databases I'd have defaultTblNode and ind

Re: [HACKERS] Spinlock performance improvement proposal

2001-09-29 Thread Vadim Mikheev
> I have committed changes to implement this proposal. I'm not seeing > any significant performance difference on pgbench on my single-CPU > system ... but pgbench is I/O bound anyway on this hardware, so that's > not very surprising. I'll be interested to see what other people > observe. (Tats

Re: [HACKERS] [BUGS] Bug #613: Sequence values fall back to previously chec

2002-03-15 Thread Vadim Mikheev
> But sequences should not be under transaction control. Can you > safely rollback a sequence? No! The only way to ensure that would ... > Placing a restriction on an application that says it must treat the values > returned from a sequence as if they might not be committed is absurd. Why? The

Re: [HACKERS] [BUGS] Bug #613: Sequence values fall back to previously chec

2002-03-15 Thread Vadim Mikheev
> | > Placing a restriction on an application that says it must treat the values > | > returned from a sequence as if they might not be committed is absurd. > | > | Why? The fact that you are not able to rollback sequences does not > | necessary mean that you are not required to perform commit to

Re: [HACKERS] Proposal for DROP TABLE rollback mechanism

2000-10-28 Thread Vadim Mikheev
> 1. smgrcreate() will create the file for the relation same as it does now, > and will add the rel's RelFileNode information to an smgr-private list of > rels created in the current transaction. > > 2. smgrunlink() normally will NOT immediately delete the file; instead it > will perform smgrclose

Re: [HACKERS] Proposal for DROP TABLE rollback mechanism

2000-10-28 Thread Vadim Mikheev
> > Mmmm, why not call FlushRelationBuffers? Calling bufmgr from smgr > > doesn't look like right thing. ? > > Yes, it's a little bit ugly, but if we call FlushRelationBuffers then we > will likely be doing some useless writes (to flush out pages that we are > only going to throw away anyway). I

Re: [HACKERS] Proposal for DROP TABLE rollback mechanism

2000-10-28 Thread Vadim Mikheev
> > BTW, why do we force buffers to disk in FlushRelationBuffers at all? > > Seems all what is required is to flush them *from* pool, not *to* disk > > immediately. > > Good point. Seems like it'd be sufficient to do a standard async write > rather than write + fsync. > > We'd still need some add

Re: [HACKERS] Numeric file names

2000-10-28 Thread Vadim Mikheev
> > Now that we have numeric file names, I would like to have a command I > > can run from psql that will dump a mapping of numeric file name to table > > name, i.e., > > > > 121233 pg_proc > > 143423 pg_index > > select oid, relname from pg_class; No. select relfilenode, relname from pg_class -

[HACKERS] WAL status update

2000-10-29 Thread Vadim Mikheev
Hi, All First, as I've already mentioned in answer to Tom about DROP TABLE, undo logic will not be implemented in 7.1 -:( Doable for tables but for indices we would need either in compensation records or in xmin/cmin in index tuples. So, we'll still live with dust from aborted xactions in our tab

Re: [HACKERS] WAL status update

2000-10-29 Thread Vadim Mikheev
> > First, as I've already mentioned in answer to Tom about DROP TABLE, undo > > logic will not be implemented in 7.1 -:( Doable for tables but for indices we > > would need either in compensation records or in xmin/cmin in index tuples. > > So, we'll still live with dust from aborted xactions in o

Re: [HACKERS] foreign key introduces unnecessary locking ?

2000-10-23 Thread Vadim Mikheev
> Using Dirty transaction removing/updating PK could see that concurrent > xaction attempts to update/insert FK and so would wait for its commit/abort. Of course this will require some function that would take tid as one of arguments, fetch row and check if someone is updating it. > Jus

Re: [HACKERS] foreign key introduces unnecessary locking ?

2000-10-23 Thread Vadim Mikheev
> > though constraint triggers should use SnapshotDirty instead of > > SELECT FOR UPDATE anyway. > > > > Did you consider this, Jan? > > Whenever the checks are done, the transaction inserting a new > reference to the key must ensure that this key cannot get > deleted until it is d

Re: [HACKERS] WAL status update

2000-11-02 Thread Vadim Mikheev
> "Mikheev, Vadim" <[EMAIL PROTECTED]> writes: > > I think that at least 1 & 2 from WAL todo (checkpoints and port to > > machines without TAS) is required before beta. > > I'm not sure that you do need to add support for machines without TAS. > I pointed out a couple months ago that the non-TAS

Re: [HACKERS] Transaction ID wraparound: problem and proposed solution

2000-11-04 Thread Vadim Mikheev
> > So, we'll have to abort some long running transaction. > > Well, yes, some transaction that continues running while ~ 500 million > other transactions come and go might give us trouble. I wasn't really > planning to worry about that case ;-) Agreed, I just don't like to rely on assumptions

Re: [HACKERS] Transaction ID wraparound: problem and proposed solution

2000-11-05 Thread Vadim Mikheev
> One idea I had from this is actually truncating pg_log at some point if > we know all the tuples have the special committed xid. It would prevent > the file from growing without bounds. Not truncating, but implementing pg_log as set of files - we could remove files for old xids. > Vadim, can

[HACKERS] WAL

2000-11-11 Thread Vadim Mikheev
Hi! I'll be in Las Vegas (Comdex) till next week Wednesday. I wasn't able to implement redo for sequences but was going to turn WAL on by default anyway. Unfortunately, I've got core in regress:opr_sanity test (in FileSeek code), so WAL still is not default. See you! Vadim

Re: [HACKERS] WAL fsync scheduling

2000-11-19 Thread Vadim Mikheev
> There are two parts to transaction commit. The first is writing all > dirty buffers or log changes to the kernel, and second is fsync of the Backend doesn't write any dirty buffer to the kernel at commit time. > log file. The first part is writing commit record into WAL buffer

Re: [HACKERS] WAL

2000-11-20 Thread Vadim Mikheev
Now WAL is ON by default. make distclean + initdb are required. Vadim

Re: [HACKERS] Re: [COMMITTERS] pgsql/src/backend/access/transam (xlog.c)

2000-11-20 Thread Vadim Mikheev
> Nope. Still fails... I know, but looks better, eh? -:) > > *** ./expected/opr_sanity.out Tue Nov 14 13:32:58 2000 > --- ./results/opr_sanity.out Mon Nov 20 20:27:46 2000 > *** > *** 482,489 > (p2.pronargs = 1 AND p1.aggbasetype = 0))); > oid | aggname | oid

Re: [HACKERS] Re: [COMMITTERS] pgsql/src/backend/access/transam (xlog.c)

2000-11-20 Thread Vadim Mikheev
> >> Larry Rosenman <[EMAIL PROTECTED]> writes: > Nope. Still fails... > > You should've said that the OIDs are now just off-by-one from where they > were before, instead of off by several thousand. That I'm willing to > accept as an implementation change ;-) I've updated the expected fil

Re: [HACKERS] Re: [COMMITTERS] pgsql/src/backend/access/transam (xlog.c)

2000-11-21 Thread Vadim Mikheev
> > Nope. Still fails... > > > > You should've said that the OIDs are now just off-by-one from where they > > were before, instead of off by several thousand. That I'm willing to > > accept as an implementation change ;-) I've updated the expected file. ^^^

Re: [HACKERS] Re: [COMMITTERS] pgsql/src/backend/access/transam (xlog.c)

2000-11-21 Thread Vadim Mikheev
> > Nope. Still fails... > > > > You should've said that the OIDs are now just off-by-one from where they > > were before, instead of off by several thousand. That I'm willing to > > accept as an implementation change ;-) I've updated the expected file. ^^^

Re: [HACKERS] RE: [COMMITTERS] pgsql/src/backend/access/transam ( xact.c xlog.c)

2000-11-15 Thread Vadim Mikheev
> > > Earlier, Vadim was talking about arranging to share fsyncs of the WAL > > > log file across transactions (after writing your commit record to the > > > log, sleep a few milliseconds to see if anyone else fsyncs before you > > > do; if not, issue the fsync yourself). That would offer less-th

Re: [HACKERS] Are pg_control contents really variable-length?

2000-11-25 Thread Vadim Mikheev
> In xlog.c, the declaration of struct ControlFileData says: > > /* > * MORE DATA FOLLOWS AT THE END OF THIS STRUCTURE - locations of data > * dirs > */ > > Is this comment accurate? I don't see any sign in the code of placing > extra data after the declared structure. If yo

Re: [HACKERS] Alternative database locations are broken

2000-11-04 Thread Vadim Mikheev
> >> I think that to handle locations we could symlink catalogs - ln -s > >> path_to_database_in_some_location .../base/DatabaseOid > > > But that's a kludge. We ought to discourage people from messing with the > > storage internals. > > It's not a kluge, it's a perfectly fine implementation.

Re: [HACKERS] RE: [COMMITTERS] pgsql/src/backend/access/transam (xact.c xlog.c)

2000-11-19 Thread Vadim Mikheev
> > > Ok, so with CHECKPOINTS, we could move the offline log files to > > > somewhere else so that we could archive them, in my > > > undertstanding. Now question is, how we could recover from disaster > > > like losing every table files except log files. Can we do this with > > > WAL? If so, how

Re: [HACKERS] beta testing version

2000-11-30 Thread Vadim Mikheev
> As for replaying logs against a restored snapshot dump... AIUI, a > dump records tuples by OID, but the WAL refers to TIDs. Therefore, > the WAL won't work as a re-do log to recover your transactions > because the TIDs of the restored tables are all different. True for current way of bac

Re: [HACKERS] beta testing version

2000-12-01 Thread Vadim Mikheev
> > > As for replaying logs against a restored snapshot dump... AIUI, a > > > dump records tuples by OID, but the WAL refers to TIDs. Therefore, > > > the WAL won't work as a re-do log to recover your transactions > > > because the TIDs of the restored tables are all different. > > > > Tru

Re: [HACKERS] beta testing version

2000-12-02 Thread Vadim Mikheev
> There is risk here. It isn't so much in the fact that PostgreSQL, Inc > is doing a couple of modest closed-source things with the code. After > all, the PG community has long acknowleged that the BSD license would > allow others to co-op the code and commercialize it with no obligations. > >

Re: [HACKERS] beta testing version

2000-12-03 Thread Vadim Mikheev
> >I totaly missed your point here. How closing source of ERserver is related > >to closing code of PostgreSQL DB server? Let me clear things: > > (not based on WAL) > > That's wasn't clear from the blurb. > > Still, this notion that PG, Inc will start producing closed-source products > poisons

Re: [HACKERS] vacuum verbose analyze lazy problem.

2000-12-14 Thread Vadim Mikheev
> I wouldn't consider it's a bug, but from my point of view it is quite strange. > Any comments? > > BTW, I did a backup, and can supply anyone interested with original table. Please send it me. Vadim

Re: [HACKERS] switching txlog file in 7.1beta

2000-12-14 Thread Vadim Mikheev
> when doing txlog switches there seems to be a problem with remembering the > correct = active logfile, when the postmaster crashes. > > This is one of the problems I tried to show up previously: > You cannot rely on writes to other files except the txlog itself !!! Why? If you handle those fi

Re: [HACKERS] switching txlog file in 7.1beta

2000-12-15 Thread Vadim Mikheev
> REDO @ 0/327312; LSN 0/327560: prev 0/327064; xprev 0/327064; xid 594: Heap - >insert: node 1 > 8719/18720; cid 0; tid 0/18 > DEBUG: ReadRecord: there is no subrecord flag in logfile 0 seg 0 off 40 ^ > DEBUG: Formatting l

[HACKERS] New WAL version (CRC & data pages backup)

2000-12-28 Thread Vadim Mikheev
just committed. initdb is required. *I didn't do any serious tests yet*, simple regression only. I'll run more tests in the next couple of days. Plase, help with this. Vadim

[HACKERS] Just fixed

2000-12-30 Thread Vadim Mikheev
a couple of bugs in new WAL code. Thanks to Tom for pointing to one of them. Initdb is recommended but you can avoid it if shutdown old version properly (format of one of heap log records was changed). Vadim

Re: [HACKERS] Quite strange crash

2001-01-09 Thread Vadim Mikheev
> > Well, it's not good idea because of SIGTERM is used for ABORT + EXIT > > (pg_ctl -m fast stop), but shouldn't ABORT clean up everything? > > Er, shouldn't ABORT leave the system in the exact state that it's > in so that one can get a crashdump/traceback on a wedged process > without it trying

Re: [HACKERS] CRCs (was Re: [GENERAL] Re: Loading optimization)

2001-01-11 Thread Vadim Mikheev
> > No, I thought we agreed disk block CRC was way overkill. If the CRC on > > the WAL log checks for errors that are not checked anywhere else, then > > fine, but I thought disk CRC would just duplicate the I/O subsystem/disk > > checks. > > A disk-block CRC would detect partially written block

[HACKERS] Re: CRCs (was Re: [GENERAL] Re: Loading optimization)

2001-01-11 Thread Vadim Mikheev
> > But CRC is used in WAL records only. > > Oh. I thought we'd agreed that a CRC on each stored disk block would > be a good idea as well. I take it you didn't do that. > > Do we want to consider doing this (and forcing another initdb)? > Or shall we say "too late for 7.1"? I personally was

Re: [HACKERS] Pg7.1beta3: connect failed: The DB System is starting up.

2001-01-12 Thread Vadim Mikheev
> With Apache Mod Perl, Apache::DBI, stress test with apache bench (ab -n > 10 -c 4) in apache error_log i've got: > > [Pg7.1beta3 with standard conf files.] And how many simult connections you did? > .. > [Fri Jan 12 07:48:58 2001] [error] DBI->connect(dbname=mydb) failed: The >

[HACKERS] Out of town these long weekends...

2001-01-13 Thread Vadim Mikheev

Re: [HACKERS] Open 7.1 items

2001-01-27 Thread Vadim Mikheev
> Here are the open items for 7.1. Much shorter: + Runtime btree recovery Vadim

Re: [HACKERS] WAL Crash during index vacuuming 7.1beta4

2001-02-05 Thread Vadim Mikheev
> during the nightly vacuum pgsql closed and do not start any more. > Attached the log. > > Seems the problem was rebuilding an Index, > There is a way to force wal to ignore indexes ? The problem was in redoing tuple movement in *table*. > Can I delete it ? > ... > > DEBUG: redo starts at (6,

Re: [HACKERS] Btree runtime recovery. Stuck spins.

2001-02-08 Thread Vadim Mikheev
> > Shouldn't we increase S_MAX_BUSY and use ERROR instead of FATAL? > > No. If you have delays exceeding a minute, or that are even a visible > fraction of a minute, then a spinlock is NOT the correct mechanism to be > using to wait ... because guess what, it's spinning, and consuming > processo

Re: [HACKERS] Btree runtime recovery. Stuck spins.

2001-02-09 Thread Vadim Mikheev
> > Hm. It was OK to use spinlocks to control buffer access when the max > > delay was just the time to read or write one disk page. But it sounds Actually, btree split requires 3 simult. buffers locks and after that _bt_getstackbuf may read *many* parent buffers while holding locks on 2 buffer

Re: [HACKERS] Recovery of PGSQL after system crash failing!!!

2001-02-11 Thread Vadim Mikheev
> DEBUG: starting up > DEBUG: database system was interrupted at 2001-02-11 04:08:12 > DEBUG: Checkpoint record at (0, 805076492) > postmaster: reaping dead processes... > Startup failed - abort > > And that is it, from running 'postmaster -D /usr/local/pgsql/data/'. I get > the same thing each t

Re: [HACKERS] Recovery of PGSQL after system crash failing!!!

2001-02-13 Thread Vadim Mikheev
> > #2 0x20dc71 in abort () from /lib/libc.so.6 > > #3 0x8080495 in XLogFileOpen () > > Hm. Evidently it's failing to open the xlog file, but the code is set > up in such a way that it dies before telling you why :-( Take a look > at XLogFileOpen in src/backend/access/transam/xlog.c and tweak

[HACKERS] Re: Recovery of PGSQL after system crash failing!!!

2001-02-14 Thread Vadim Mikheev
> > It removes the need to disable fsync to get best performance! > > -F performance is still better, only the difference is not so big as before. Well, when "checkpoint seek in logs" will be implemented difference will be the same - lost consistency. > > Since there is a fundamental recovery

Re: [HACKERS] Open 7.1 items

2001-02-14 Thread Vadim Mikheev
> As you can see from the current open items list, there isn't much left > to do for the 7.1 release. I am going to suggest we remove the LAZY > VACUUM option at this point. I know Tom Lane posted an item about the Well, leaving for vacation tomorrow I have to agree -:( LAZY patch will be avail

Re: [HACKERS] RE: [ADMIN] SOS !!: Porstgress forgot all ! Help !

2001-02-14 Thread Vadim Mikheev
> > O, your system reached max transaction ID -:( > > That's two reports now of people who have managed to wrap around the XID > counter. It doesn't seem that hard to do in a heavily used database. > > Does anyone want to take more seriously the stopgap solution I proposed > for this proble

[HACKERS] Leaving for vacation

2001-02-14 Thread Vadim Mikheev
from Feb 15 till Mar 6... I'll not be able to read mail lists, so in the event of needs please use [EMAIL PROTECTED] address. Regards! Vadim

Re: [HACKERS] RE: Re: [ADMIN] v7.1b4 bad performance

2001-02-23 Thread Vadim Mikheev
> > > It may be that WAL has changed the rollback > > > time-characteristics to worse than pre-wal ? > > > > Nothing changed ... yet. And in future rollbacks > > of read-only transactions will be as fast as now, > > anyway. > > What about rollbacks of a bunch uf inserts/updates/deletes? > > I rem

Re: [HACKERS] RE: Re: [ADMIN] v7.1b4 bad performance

2001-02-23 Thread Vadim Mikheev
> It may be that WAL has changed the rollback > time-characteristics to worse than pre-wal ? Nothing changed ... yet. And in future rollbacks of read-only transactions will be as fast as now, anyway. > > So my guess is that the 7.1 updates (with default > > fsync) are significantly slower than 7

Re: [HACKERS] RE: Re: [ADMIN] v7.1b4 bad performance

2001-02-27 Thread Vadim Mikheev
> So 7.0.3 is twice as fast only with fsync off. Are there FK updates/deletes in pgbench' tests? Remember how SELECT FOR UPDATE in FK triggers affects performance... Also, 5 clients is small number. Vadim P.S. Sorry for delays with my replies - internet connection is pain here: it takes 5-10 min

Re: [HACKERS] WAL does not recover gracefully from out-of-disk-space

2001-02-27 Thread Vadim Mikheev
>> Regardless of whether this particular behavior is fixable, >> this brings up something that I think we *must* do before >> 7.1 release: create a utility that blows away a corrupted >> logfile to allow the system to restart with whatever is in >> the datafiles. Otherwise, there is no recovery t

[HACKERS] RE: [CORE] WAL & RC1 status

2001-03-05 Thread Vadim Mikheev
> I've reported the major problems to the mailing lists > but gotten almost no feedback about what to do. I can't comment without access to code -:( > commit: 2001-02-26 17:19:57 > 0/0059996C: prv 0/00599948; xprv 0/; xid 0; > RM 0 info 00 len 32 > checkpoint: redo 0/0059996C; undo 0/00

[HACKERS] I'm back

2001-03-06 Thread Vadim Mikheev
Hi! Snow in New York -> I'm arrived only today. Reading mail... Vadim ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster

[HACKERS] Re: Uh, this is *not* a 64-bit CRC ...

2001-03-06 Thread Vadim Mikheev
> This isn't a 64-bit CRC. It's two independent 32-bit CRCs, one done > on just the odd-numbered bytes and one on just the even-numbered bytes > of the datastream. That's hardly any stronger than a single 32-bit CRC; I believe that the longer data the more chance to get same CRC/hash for differ

Re: AW: [HACKERS] Proposed WAL changes

2001-03-07 Thread Vadim Mikheev
> > I thought the intended way to change a GUC parameter permanently was to > > edit data/postgresql.conf . No ? > > > > What I've thought is to implement a new command to > change archdir under WAL's control. > If it's different from Vadim's plan I don't object. Actually, I have no concrete pla

Re: AW: AW: AW: AW: [HACKERS] WAL-based allocation of XIDs is insecur e

2001-03-07 Thread Vadim Mikheev
> Before commit or rollback the xlog is not flushed to disk, thus you can loose > those xlog entries, but the index page might already be on disk because of > LRU buffer reuse, no ? No. Buffer page is written to disk *only after corresponding records are flushed to log* (WAL means Write-Ahead-Log

Re: [HACKERS] Proposed WAL changes

2001-03-07 Thread Vadim Mikheev
> I have just sent to the pgsql-patches list a rather large set of Please send it to me directly - pgsql-patches' archieve is dated by Feb -:( > proposed diffs for the WAL code. These changes: > > * Store two past checkpoint locations, not just one, in pg_control. > On startup, we fall back

Re: [HACKERS] How to shoot yourself in the foot: kill -9 postmaster

2001-03-07 Thread Vadim Mikheev
> I have spent several days now puzzling over the corrupted WAL logfile > that Scott Parish was kind enough to send me from a 7.1beta4 crash. > It looks a lot like two different series of transactions were getting > written into the same logfile. I'd been digging like mad in the WAL > code to try

Re: AW: AW: AW: AW: [HACKERS] WAL-based allocation of XIDs is insecur e

2001-03-07 Thread Vadim Mikheev
> > > Before commit or rollback the xlog is not flushed to disk, thus you can loose > > > those xlog entries, but the index page might already be on disk because of > > > LRU buffer reuse, no ? > > > > No. Buffer page is written to disk *only after corresponding records are flushed > > to log* (W

Re: [HACKERS] WAL-based allocation of XIDs is insecure

2001-03-07 Thread Vadim Mikheev
> Consider the following scenario: > > 1. A new transaction inserts a tuple. The tuple is entered into its > heap file with the new transaction's XID, and an associated WAL log > entry is made. Neither one of these are on disk yet --- the heap tuple > is in a shmem disk buffer, and the WAL entr

Re: [HACKERS] WAL-based allocation of XIDs is insecure

2001-03-07 Thread Vadim Mikheev
> The point is to make the allocation of XIDs and OIDs work the same way. > In particular, if we are forced to reset the XLOG using what's stored in > pg_control, it would be good if what's stored in pg_control is a value > beyond the last-used XID/OID, not a value less than the last-used ones. I

Re: [HACKERS] WAL-based allocation of XIDs is insecure

2001-03-07 Thread Vadim Mikheev
Zeugswetter Andreas SB <[EMAIL PROTECTED]> wrote: > > In short I do not think that the current implementation of > "physical log" does what it was intended to do :-( Hm, wasn't it handling non-atomic disk writes, Andreas? And for what else "physical log" could be used? The point was - copy entir

Re: [HACKERS] WAL-based allocation of XIDs is insecure

2001-03-07 Thread Vadim Mikheev
> On third thought --- we could still log the original page contents and > the modification log record atomically, if what were logged in the xlog > record were (essentially) the parameters to the operation being logged, > not its results. That is, make the log entry before you start doing the > m

Re: [HACKERS] WAL-based allocation of XIDs is insecure

2001-03-07 Thread Vadim Mikheev
> > Hm, wasn't it handling non-atomic disk writes, Andreas? > > Yes, but for me, that was only one (for me rather minor) issue. > I still think that the layout of PostgreSQL pages was designed to > reduce the risc of a (heap) page beeing inconsistent because it is > only partly written to an acc

Re: [HACKERS] Proposed WAL changes

2001-03-08 Thread Vadim Mikheev
What do we debate? I never told that we shouldn't worry about current WAL disability to restart. And WAL already correctly works in situation of "failing to write a couple of disk blocks when the system crashes". My statement at first place that "WAL can't help in the event of disk errors" was to

Re: [HACKERS] WAL does not recover gracefully from out-of-disk-space

2001-03-08 Thread Vadim Mikheev
> Was the following bug already fixed ? I was going to ask same Q. I see that seek+write was changed to write-s in XLogFileInit (that was induced by subj, right?), but what about problem itself? > > DEBUG: redo starts at (0, 21075520) > > The Data Base System is starting up > > DEBUG: open(log

Re: AW: AW: AW: [HACKERS] WAL does not recover gracefully from ou t-of -dis k-sp ace

2001-03-10 Thread Vadim Mikheev
> > Ok, I've made changes in xlog.c and run tests: > > Could you send me your diffs? Sorry, Monday only. Vadim ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]

Re: [HACKERS] RE: xlog loose ends, continued

2001-03-13 Thread Vadim Mikheev
> > Anyway I like idea of StartUpID in page headers - this will help > > Can you please describe StartUpID for me ? > Ideal would be a stamp that has the last (smallest open) XID, or something else > that has more or less timestamp characteristics (without the actual need of >wallclock) > in r

Re: [HACKERS] RE: xlog loose ends, continued

2001-03-13 Thread Vadim Mikheev
> > StartUpID counts database startups and so has timestamp characteristics. > > Actually, idea is to use SUI in future to allow reusing XIDs after startup: seeing > > old SUI in data pages we'll know that all transaction on this page was committed > > "long ago" (ie visible from MVCC POV). This r

Re: [HACKERS] Stuck spins in current

2001-03-17 Thread Vadim Mikheev
> At this point I must humbly say "yes, you told me so", because if I No, I didn't - I must humbly say that I didn't foresee this deadlock, so "I didn't tell you so" -:) Anyway, deadlock in my tests are very correlated with new log file creation - something probably is still wrong... Vadim -

Re: [HACKERS] Stuck spins in current

2001-03-21 Thread Vadim Mikheev
> > BTW, I've got ~320tps with 50 clients inserting (int4, text[1-256]) > > records into 50 tables (-B 16384, wal_buffers = 256) on Ultra10 > > with 512Mb RAM, IDE (clients run on the same host as server). > > Not bad. What were you getting before these recent changes? As I already reported - w

[HACKERS] BufferSync() & FlushRelationBuffers() conflict

2001-03-21 Thread Vadim Mikheev
Just committed changes in bufmgr.c Regress tests passed but need more specific tests, as usually. Descr as in CVS: > Check bufHdr->cntxDirty and call StartBufferIO in BufferSync() > *before* acquiring shlock on buffer context. This way we should be > protected against conflicts with FlushRelation

Re: [HACKERS] BufferSync() & FlushRelationBuffers() conflict

2001-03-21 Thread Vadim Mikheev
> > Tom, since you appear to be able to recreate the bug, can you comment on > > this, as to whether we are okay now? > > Sorry for the delay --- I was down in Norfolk all day, and am just now > catching up on email. I will pull Vadim's update and run the test some > more. However, last night I

Re: [HACKERS] WAL replay logic (was Re: [PERFORM] Mount options f

2003-02-18 Thread Vadim Mikheev
> > > > So if you do this, do you still need to store that information in > > > > pg_control at all? > > > > Yes: to "speeds up the recovery process". > > If it's going to slow down the performance of my database when not doing > recovery (because I have to write two files for every transaction, >

[HACKERS] Farewell

2003-08-10 Thread Vadim Mikheev
Title: Farewell It's time for formal acknowledgement that I'm not in The Project any more.   I'm not interested in small features/fixes and have no time for big ones. It was this way for very long time and I don't see how/when that could change.   My participation in The Project was one of t

[HACKERS] WAL status & todo

2000-10-14 Thread Vadim Mikheev
Well, hopefully WAL will be ready for alpha testing in a few days. Unfortunately at the moment I have to step side from main stream to implement new file naming, the biggest todo for integration WAL into system. I would really appreciate any help in the following issues (testing can start regardl

Re: [HACKERS] backup and restore

2000-10-14 Thread Vadim Mikheev
>> No, 2nd. WAL reflects layout of tuples in data files, so I don't see >> how pg_dump output could be used. >> I'll really appreciate if someone will help with this issue ... after >> alpha testing will start next week. > > Where is this code? How can we get it? Code is in CVS. Philip Warner al

Re: [HACKERS] SetQuerySnapshot() for utility statements

2000-10-19 Thread Vadim Mikheev
> I notice that ProcessUtility() calls SetQuerySnapshot() for FETCH > and COPY TO statements, and nothing else. > > Seems to me this is very broken. Isn't a query snapshot needed for > any utility command that might do database accesses? Not needed. We don't support multi-versioning for schema o

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