Re: [HACKERS] varchar/char size - Mailing list pgsql-hackers

From darrenk@insightdist.com (Darren King)
Subject Re: [HACKERS] varchar/char size
Date
Msg-id 9801091443.AA42084@ceodev
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List pgsql-hackers
>
> A related question: Is it possible to store tuples over more than one
> block? Would it be possible to split a big TEXT into multiple blocks?
>

Possible, but would cut the access speed to (1 / # blocks), no?

There is a var in the tuple header, t_chain, 6.2.1 that has since been
removed for 6.3.  I think its original purpose was with time-travel,
_but_, if we go with a ROWID instead of an oid in the future, this could
be put back in the header and would be the actual address of the next
block in the chain.

Oracle has this concept of chained rows.  It is how they implement all
of their LONG* types and also handle rows of normal types that are
larger than the block size.

darrenk

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