Re: [HACKERS] 6.4.x

> Tom Lane wrote:
> > 
> > >>>> (3) does 6.4 support query lengths > 8192, or data blocks > 8192
> > >>>> (other than large objects)?
> > 
> > > Sometime in the past Darren K. worked to parameterize this limit.
> > 
> > There has been some discussion of allowing tuples to span multiple
> > disk blocks, which would remove the problem entirely, but it hasn't
> > happened yet.  Maybe for 6.5?
> 
> Right now I'm rewriting HeapTuple structure and functions - for
> multi-version concurrency control (MVCC). New HeapTuple:
> 
> typedef struct HeapTupleData
> { 
>     uint32              t_len;      /* length of *t_data */
>     ItemPointerData     t_self;     /* SelfItemPointer */
>     HeapTupleHeader     t_data;     /* */
>     ^^^^^^^^^^^^^^^^^^^^^^^^^^
>     this is what known as HeapTuple in < 6.5
> } HeapTupleData;
> 
> I assume that one, who would like implement blocks spanning, 
> will add something to this new structure. 
> I need in ~ one week, please wait.

Block spanning was only an idea.  No idea how to code it.  Yet.

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