Re: [WIP] Reduce alignment requirements on 64-bit systems. - Mailing list pgsql-hackers

From Zdenek Kotala
Subject Re: [WIP] Reduce alignment requirements on 64-bit systems.
Date
Msg-id 48ED9DC8.4000501@sun.com
Whole thread Raw
In response to [WIP] Reduce alignment requirements on 64-bit systems.  ("Ryan Bradetich" <rbradetich@gmail.com>)
Responses Re: [WIP] Reduce alignment requirements on 64-bit systems.
List pgsql-hackers
Just a quick look. At first point. Your change introduces new page layout 
version. Which is not acceptable from my point of view for 8.4 (it add another 
complexity to inplace upgrade). And I guest that it maybe works fine on 64bits 
x86 but it will fail on SPARC and other machine which requires aligned data.
    Zdenek


Ryan Bradetich napsal(a):
> Hello all,
> 
> Here is a proof-of-concept patch for reducing the alignment
> requirement for heap tuples on 64-bit systems.
> This patch passes the regression tests and a couple of other data sets
> I have thrown at it.
> 
> I am hoping to get some early feedback on this patch so I have time to
> make any corrections, improvements,
> etc before the November commit-fest deadline.
> 
> There are two visible savings in the system catalogs using this patch
> (size was gathered using \S+):
> 
> Catalog              Pre-Patch Size      After Patch Size
> 
> pg_depend         312 kB                  296 kB
> pg_description    160 kB                  152 kB
> 
> 
> One thing I am considering, but I am not sure if it is worth the code
> uglification, is to wrap the majority of these
> checks in #ifdefs so they only are used on 64-bit systems.   This
> would completely eliminate the impact for this
> patch on 32-bit systems, which would not gain any benefit from this patch.
> 
> Feedback welcome!
> 
> Thanks,
> 
> - Ryan
> 
> 
> ------------------------------------------------------------------------
> 
> 


-- 
Zdenek Kotala              Sun Microsystems
Prague, Czech Republic     http://sun.com/postgresql



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