[HACKERS] table-level and row-level locks.
Iam trying to acquire rowlevel locks in postgresql. I try doing this: 'select * from students where name='Larry' for update; But by looking at the holding array of proclock , I've noticed that by doing this only AccessShareLock gets acquired which is a table level lock. How do I acquire rowlevelock and what fields of Lock or Proclock datastructures indicate it. Thanks JennyHelp STOP SPAM with the new MSN 8 and get 2 months FREE*
[HACKERS] btree fast-root on VACUUM FULL
Hackers (especially Tom), Would it be right to set the fast-root as true root during a VACUUM FULL? This would free all pages between true root and fast root. (I'm not advocating to do it, nor volunteering; I'm merely wondering). -- Alvaro Herrera (alvherre[a]dcc.uchile.cl) Ninguna manada de bestias tiene una voz tan horrible como la humana (Orual) ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [HACKERS] btree fast-root on VACUUM FULL
Alvaro Herrera [EMAIL PROTECTED] writes: Would it be right to set the fast-root as true root during a VACUUM FULL? This would free all pages between true root and fast root. Possibly okay, but why bother? It's hardly likely to free a meaningful number of pages. And I think you'd need to invent another category of WAL record to log the action, so the code overhead to make it happen isn't trivial. regards, tom lane ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org
Re: [HACKERS] Transaction handling in extended query mode and Sync
Carlos Guzman Alvarez wrote: Hello: Hello Carlos. I continue to work in the implementation of the 3.0 protocol in C#, i'm making a test that consist on: - Create a database. - Create a table in the new database. - Start transaction. - Insert 100 rows of data in the new table. - Commit transaction. For start a transaction i send a Query message with this as statement text: START TRANSACTION ISOLATION LEVEL READ COMMITTED For commit a transaction i send a Query message with this as statement text: COMMIT TRANSACTION For execute the inserts i use parametrized commands with Extended query mode, sending this sequence of messages: - Parse Flush ( Only for the first command ) - Describe Flush ( Only for the first command ) - Close Portal ( begining at second command ) - Bind Flush - Execute Sync But the Sync message seems to be commiting the transaction, if i send a Flush message all works as expected with inserts, but create database table will not work. Sorry for late response... I could finally get Npgsql to talk protocol 3.0 version :) It is not 100% but it is near... I give it a try in a test similar to yours... I didn't send the create database commands just the row insertion. in both sequences, I could get the desired behaviour. I could send the begin transaction in simple query mode, send the insert in extended mode and send a commit or rollback in simple mode sending the sync message in the end of extended mode. Are you still having problems with it? I hope it helps. -- Regards, Francisco Figueiredo Jr. -- My grandfather once told me that there are two kinds of people: those who work and those who take the credit. He told me to try to be in the first group; there was less competition there. - Indira Gandhi ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
[HACKERS] corrupt data
Hi List Out of some reason our data of our postgresql database has been corrupted. When we try to connect to the database we get: psql: ERROR: _mdfd_getrelnfd: cannot open relation pg_type_oid_index: No such file or directory REINDEX does not work. We get the same error. pgfsck gives us: wrong blockseize. We are using postgresql 7.3.3-1 (debian). Thanks for any hints and feedback. Zeno ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster
Re: [HACKERS] again: Bug #943: Server-Encoding from
Tatsuo Ishii wrote: I have looked into my Linux box and found this in /usr/share/i18n/charmaps/BIG5.gz: % Chinese charmap for BIG5 (CP950) % version: 0.92 % Contact: Tung-Han Hsieh [EMAIL PROTECTED] % Yuan-Chung Cheng [EMAIL PROTECTED] % Distribution and use is free, even for comercial purpose. % % This charmap is converted from: % ftp://ftp.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WINDOWS/CP950.TXT % ... There my characters are in. That's a M$'s definition, not a standard. I think there should be a reason why the Unicode org. does not use it. Ok, I do not know the reason. But since also the glibc uses it, couldn't you use it too? I believe the glibc delveloper have thought about this a lot. And they came to the conclusion to use this definition. Why not postgresql? Don't you agree that it is strange that I can (for EUC_TW) copy to file without error but I can not copy from file without error? I'm not quite sure what you are saying. Are you complaining that (for example) 0xe7a281 in UTF-8 does not convert to EUC_TW? Yes exactly, since this value comes from a copy to with PGCLIENTENCODING=EUC_TW BTW, what do you think about below? FYI, CNS 11643-1993 is the standard character set and EUC_TW is the one of the encodings. That means your problem below will disappear. Ok. Regards, Michael WARNING: copy: line 2, LocalToUtf: could not convert (0x8ea3cfd0) EUC_TW to UTF-8. Ignored WARNING: copy: line 3, LocalToUtf: could not convert (0x8ea3c4ce) EUC_TW to UTF-8. Ignored WARNING: copy: line 4, LocalToUtf: could not convert (0x8ea3bdfe) EUC_TW to UTF-8. Ignored Hum. These seem to be CNS 11643-1993, plane 3. Currently PostgreSQL supports only: CNS 11643-1993, plane 0 CNS 11643-1993, plane 1 CNS 11643-1993, plane 2 CNS 11643-1993, plane 15 Would you like to have support for rest of CNS 11643-1993 planes: CNS 11643-1993, plane 3 CNS 11643-1993, plane 4 CNS 11643-1993, plane 5 CNS 11643-1993, plane 6 CNS 11643-1993, plane 7 support for upcoming 7.4? -- Tatsuo Ishii ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster
Re: [HACKERS] [GENERAL] PG crash on simple query, story continues
So following modification seems to fixed all PG (7.3/7.3.3)crashes on
Solaris ( NON C LOCALE )
selfuncs.c line 2356:
I changed:
xfrmsize = strlen(val) + 32;/*arbitrary pad value here...*/
to
xfrmsize = strxfrm(NULL, val, 0) + 32;
so basically instead of wild guess of transformed string size I asking
strxfrm for that.
+32 out my desperation, strxfrm(NULL, val, 0) + 1 should be fine ( have
not tested that )...
Out of curiosity:
Really interesting, following condition seems to be impossible anymore,
of cause if something went terribly wrong,
die here, return original string, return empty string?
if (xfrmlen = xfrmsize) {
pfree(xfrmstr);
xfrmstr = (char *) palloc(xfrmlen + 1);
xfrmlen = strxfrm(xfrmstr, val, xfrmlen + 1);
}
Again fixed all crashes on Sun 5.8 ( PG 7.3.3, en_US locale, LATIN1
encoding ) Generic Patch...
P.S
NO SUPPORT, NO WARRANTY, NO NOTHING, just for you information.
Regards.
-Original Message-
From: Tom Lane [mailto:[EMAIL PROTECTED]
Sent: Tuesday, July 08, 2003 3:58 PM
To: Maksim Likharev
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: [GENERAL] PG crash on simple query, story continues
Maksim Likharev [EMAIL PROTECTED] writes:
On failure, strxfrm() returns (size_t)-1.
Not according to the Single Unix Specification, Linux, or HP-UX;
I don't have any others to check. But anyway, that is not causing
your problem, since palloc(0) would complain not dump core.
I am on SunOS 5.8,
Solaris, eh? IIRC, it was Solaris that we last heard about broken
strxfrm on. Better check to see if Sun has a fix for this.
regards, tom lane
---(end of broadcast)---
TIP 7: don't forget to increase your free space map settings
