Re: [HACKERS] Arbitrary tuple size

Going toward >8k tuples would be really good, but I suspect we may
some difficulties with LO stuffs once we implement it. Also it seems
that it's not worth to adapt LOs with newly designed tuples.  I think
the design of current LOs are so broken that we need to redesign them.

o it's slow: accessing a LO need a open() that is not cheap.  creating
many LOs makes data/base/DBNAME/ directory fat.

o it consumes lots of i-nodes

o it breaks the tuple abstraction: this makes difficult to maintain
the code.

I would propose followings for the new version of LO:

o create a new data type that represents the LO

o when defining the LO data type in a table, it actually points to a
LO "body" in another place where it is physically stored.

o the storage for LO bodies would be a hidden table that contains
several LOs, not single one.

o we can have several tables for the LO bodies. Probably a LO body
table for each corresponding table (where LO data type is defined) is
appropreate. 

o it would be nice to place a LO table on a separate
directory/partition from the original table where LO data type is
defined, since a LO body table could become huge.

Comments? Opinions?
---
Tatsuo Ishii