[pgpool-hackers: 4320] Re: minimal parser and multi-statement query

[Tatsuo Ishii]

Hi Usama,

> Thanks for conducting the tests.

No prolem.

> 3-4 % seems quite a significant degradation. So one possible way would bet
> retire the
> minimal parser and always use the standard parser so that we can save the
> extra scanning
> needed for the detection of multi-statement queries.
> 
> It (removing minimal parser altogether) may be less of a performance
> overhead than this. What is your opinion?

Is it possible to run the extra scanning only for lengthy queries(say,
longer than 10k)? i.e.

If (lengthy query)
  extra scanning;
  if (single-statement)
    minimal_parser = true;
  else
    minimal_parser = false;
else
  minimal_parser = false;
fi
raw_parser (minimal_parser);

With this, we can avoid the extra scanning for most queries. I think
the minimal parser is best for lengthy queries.

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp