Re: [HACKERS] tables > 1 gig - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [HACKERS] tables > 1 gig
Date
Msg-id 199906171513.LAA25295@candle.pha.pa.us
Whole thread Raw
Responses Re: [HACKERS] tables > 1 gig
List pgsql-hackers
> Bruce Momjian <maillist@candle.pha.pa.us> writes:
> >> Then we'd better fix the underlying problem.  We can't change
> >> RELSEG_SIZE for a minor release, unless you want to give up the
> >> principle of not forcing initdb at minor releases.
> 
> > Why can't we increase it?
> 
> Consider a 1.5-gig table.  6.5 will store it as one gig in file "table",
> one-half gig in file "table.1".  Now recompile with larger RELSEG_SIZE.
> The file manager will now expect to find all blocks of the relation in
> file "table", and will never go to "table.1" at all.  Presto, you lost
> a bunch of data.
> 
> Bottom line is just as it says in the config.h comments: you can't
> change either BLCKSZ or RELSEG_SIZE without doing initdb.

OK. I will reverse it out.  I never thought that far ahead.  Not sure
how we can fix this easily, nor do I understand why more people aren't
complaining about not being able to vacuum tables that are 1.5 gigs that
they used to be able to vacuum.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 


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