Re: Performance Improvement by reducing WAL for Update Operation

On 7/9/13 12:09 AM, Amit Kapila wrote:
>    I think the first thing to verify is whether the results posted can be validated in some other environment setup by another person.
>    The testcase used is posted at below link:
>    http://www.postgresql.org/message-id/51366323.8070606@vmware.com

That seems easy enough to do here, Heikki's test script is excellent. 
The latest patch Hari posted on July 2 has one hunk that doesn't apply 
anymore now.  Inside src/backend/utils/adt/pg_lzcompress.c the patch 
tries to change this code:

-               if (hent)
+               if (hentno != INVALID_ENTRY)

But that line looks like this now:

                 if (hent != INVALID_ENTRY_PTR)

Definitions of those:

#define INVALID_ENTRY                   0
#define INVALID_ENTRY_PTR               (&hist_entries[INVALID_ENTRY])

I'm not sure if different error handling may be needed here now due the 
commit that changed this, or if the patch wasn't referring to the right 
type of error originally.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
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