[comp.databases] INGRES checkpoint problem

rrg@ibism.UUCP (Renato Ghica) (05/23/91)

I have a problem recovering an INGRES database using the
checkpoint/journal files:

Environment:
	SunOs 4.1.1, Ingres 6.3

The system that I have set up is just about to go live, and I'm testing
various recovery procedures.
	
	The application database is on disk A
	The ckp,dmp,jnl files are on disk B
	The log file is on disk C
	The II_DATABASE is on the system disk
	The application database is accessed using a location name

I want to recover the entire database using the last checkpoint.
--------------------------------------------------------------------------

Now, when I simulate the thrashing of the application database disk by 
renaming it (ie /appr_db/ingres/data/default/mydb becomes 
/appr_db/ingres_tmp/data/default/mydb), I have to recreate the directory
structure, with the appropriate protections.

When I do this and I try to ROLLFORWARDDB from the last checkpoint,
(into an empty /appr_db/ingres/data/default/mydb), I get an error .
	
	something like "Cannot find aaaaaaaa.cnf file in
	/appr_db/ingres/data/default/mydb "

In VMS, it seems that this configuration file is re-created
automatically, but not here.
--------------------------------------------------------------------------
I overcome this problem by extracting the aaaaaaaa.cnf from the latest
	checkpoint and putting in the directory path. now I get a different
	error : "Error recovering from incomplete checkpoint"
    when I do the rollforwarddb .

(if I destroydb and createdb to get the cnf file, the journals, logs
and ckp get destroyed unless I hide them)

------------------------------------------------------------------------
What is happening here ? my questions are:

	- why is the configuration file (aaaaaaaa.cnf) not recreated
	  automatically from the checkpoint ?

	- Can the checkpoint receovery process be used when the entire
	  directory is wiped out ?(as above)

	- Has anybody experienced this (trying to recover from a deleted
	  database directory tree ) using only the checkpoint and journal ?
	  (maybe with a test database ?)
HELP ! 


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    Renato Ghica	
	Citibank                           Phone:   (212) 657-7664 
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