Re: Fwd: [GENERAL] 4B row limit for CLOB tables - Mailing list pgsql-hackers

From José Luis Tallón
Subject Re: Fwd: [GENERAL] 4B row limit for CLOB tables
Date
Msg-id 553F63D6.3060507@adv-solutions.net
Whole thread Raw
In response to Re: Fwd: [GENERAL] 4B row limit for CLOB tables  (Jim Nasby <Jim.Nasby@BlueTreble.com>)
Responses Re: Fwd: [GENERAL] 4B row limit for CLOB tables
List pgsql-hackers
On 04/27/2015 08:49 AM, Jim Nasby wrote:
> On 4/25/15 1:19 PM, Bruce Momjian wrote:
>>     Note if you are storing a table with rows that exceed 2KB in size
>>     (aggregate size of each row) then the "Maximum number of rows in a
>>     table" may be limited to 4 Billion, see TOAST.
>
> That's not accurate though; you could be limited to far less than 4B 
> rows. If each row has 10 fields that toast, you'd be limited to just 
> 400M rows.

ISTM like the solution is almost here, and could be done without too 
much (additional) work:
* We have already discussed having a page-per-sequence with the new 
SeqAMs being introduced and how that would improve scalability.
* We have commented on having a sequence per TOAST table    (hence, 4B toasted values per table each up to 4B chunks in
size...
 
vs just 4B toasted values per cluster)
    I'm not sure that I can do it all by myself just yet, but I sure 
can try if there is interest.    (just after I'm done with another patch that is independent from 
this, though)
    This would be material for 9.6, of course :)

Thanks,
    J.L.




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