Re: Speed up transaction completion faster after many relations areaccessed in a transaction

On 2/12/19 7:33 AM, Tsunakawa, Takayuki wrote:
> ...
> 
> This problem was uncovered while evaluating partitioning performance.
> When the application PREPAREs a statement once and then
> EXECUTE-COMMIT repeatedly, the server creates a generic plan on the
> 6th EXECUTE.  Unfortunately, creation of the generic plan of
> UPDATE/DELETE currently accesses all partitions of the target table
> (this itself needs improvement), expanding the LOCALLOCK hash table.
> As a result, 7th and later EXECUTEs get slower.
> 
> Imai-san confirmed performance improvement with this patch:
> 
> https://commitfest.postgresql.org/22/1993/
> 

Can you quantify the effects? That is, how much slower/faster does it get?

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
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