[HACKERS] Control File
Quick (real) story to illustrate situation: Some time ago we used to have a server with 2 disk arrays attached to it. They were /mnt/array1 and /mnt/array2. PostgreSQL (8.0) had tablespaces on both. In one cold & dark night, one SCSI controller from array2 stopped, and manufacturer was called to replace it. The "system administrator" (monkey) from the night called the DBA (sleeping...monkey? -- ups... that's me), and asked for him to stop the database so he could umount /mnt/array2. Sleeping DBA took his coffee, and stopped the database. Monkey umounted array2 and changed the SCSI controller which came alive again! Monkey calls & wake DBA (again): - Everything went fine, SCSI controller "successfully" replaced. Could you please wake up again and start the database? DBA takes another coffee and finally started the database which... just came up! Few minutes latter lot off errors being displayed. What is that??? /mnt/array2 (50% of datafiles and tablespaces were there) was still umounted and even so PostgreSQL came up. -- PostgreSQL stopped, /mnt/array2 mounted, started and... - happy end! After that night, I started to ask myself if PostgreSQL should not have a control file to check if expected datafiles are where they should be and JUST warn about missing ones? If yes, I apply for developing the patch. C ya, Teolupus ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [HACKERS] Control File
OK! I'll create a shell script to verify it. If you change your mind latter I apply for developing the patch. Best Regards, Bruno -Original Message- From: Tom Lane [mailto:[EMAIL PROTECTED] Sent: Thursday, April 13, 2006 1:57 AM To: Bruce Momjian Cc: Bruno Almeida do Lago; pgsql-hackers@postgresql.org Subject: Re: [HACKERS] Control File Bruce Momjian writes: > Bruno Almeida do Lago wrote: >> After that night, I started to ask myself if PostgreSQL should not have a >> control file to check if expected datafiles are where they should be and >> JUST warn about missing ones? > I don't think this happens frequently enough to add code for it. I think we saw it happen once to Joe Conway's DB. But I see no particular reason why Postgres needs a feature for this --- you can stick a test into your database start script if you need it. regards, tom lane ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [HACKERS] Control File
Tom, With the new tablespace scenario in mind, how do you see this check feature being implemented: as a script or inside the code? As I said before, I apply for the creation of this patch. We just need to decide the best way to implement it. Regards, Bruno Almeida do Lago -Original Message- From: Tom Lane [mailto:[EMAIL PROTECTED] Sent: Saturday, April 15, 2006 4:11 PM To: Jim C. Nasby Cc: Bruce Momjian; Bruno Almeida do Lago; pgsql-hackers@postgresql.org Subject: Re: [HACKERS] Control File "Jim C. Nasby" <[EMAIL PROTECTED]> writes: > Perhaps an easy means would be to put a PG_VERSION file in each > tablespace when it's created and then check all of them. Tablespaces > arguably make it slightly easier to accidentally try and mount something > from a different version... I believe we already do put a PG_VERSION file in each tablespace, but AFAIR there is no subsequent check on their contents. regards, tom lane ---(end of broadcast)--- TIP 6: explain analyze is your friend
Re: [HACKERS] LDAP Authentication?
I can help on this one too. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Euler Taveira de Oliveira Sent: Monday, October 31, 2005 9:44 AM To: Satoshi Nagayasu; Magnus Hagander Cc: PostgreSQL-development Subject: Re: [HACKERS] LDAP Authentication? --- Magnus Hagander wrote: > > It should be fairly easy to write a LDAP "backend" to password > > authentication using openldap, winldap or whatever ldap library is > > available. > > I support the idea. It would be a good gain for PostgreSQL authentication. If you want to discuss ideas, drop me a line. Euler Taveira de Oliveira euler[at]yahoo_com_br ___ Promoção Yahoo! Acesso Grátis: a cada hora navegada você acumula cupons e concorre a mais de 500 prêmios! Participe! http://yahoo.fbiz.com.br/ ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match ---(end of broadcast)--- TIP 6: explain analyze is your friend
[HACKERS] Control File
Hi, Today I was playing with our test environment and noticed that if I delete a PostgreSQL datafile (with cluster down) and bring up the database, It will simple... come up :-/ I wonder if it shouldn't complain about the missing datafile before opening the cluster... I don't know... Maybe something like the oracle control file which stores information about the files needed to start the database. It seems pretty easy to do it (I may be wrong...). What do you think? Are there any special reasons for PostgreSQL not complain about the missing datafiles on startup? Would that be hard to implement (maybe I could do it). C ya, Bruno ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
