From: valgog <valgog@gmail.com>
To: pgsql-performance@postgresql.org
Subject: Re: Key/Value reference table generation: INSERT/UPDATE performance
Date: 22 May 2007 03:00:41 -0700
Message-ID: <1179828041.761272.152380@x35g2000prf.googlegroups.com> (raw)
In-Reply-To: <1179822183.740891.271130@n59g2000hsh.googlegroups.com>
References: <1179822183.740891.271130@n59g2000hsh.googlegroups.com>
I have rewritten the code like
existing_words_array := ARRAY( select word
from WORD_COUNTS
where word = ANY
( array_of_words ) );
not_existing_words_array := ARRAY( select distinct_word
from ( select distinct
(array_of_words)[s.index] as distinct_word
from
generate_series(1, array_upper( array_of_words, 1 ) ) as s(index)
) as distinct_words
where distinct_word <> ALL
( existing_words_array ) );
-- insert the missing words
if not_existing_words_array is not null then
insert into WORD_COUNTS
( word, count )
( select word, 1
from ( select
not_existing_words_array[s.index] as word
from generate_series( 1,
array_upper( not_existing_words_array, 1 ) ) as s(index) ) as
distinct_words
);
end if;
-- update the counts
if existing_words_array is not null then
update WORD_COUNTS
set count = COALESCE( count, 0 ) + 1
where sw_word = ANY ( existing_words_array );
end if;
Now it processes a million records in 14 seconds... so it was probably
the problem of looking up NOT IN WORD_COUNTS was way too expencive
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: valgog@gmail.com
Subject: Re: Key/Value reference table generation: INSERT/UPDATE performance
In-Reply-To: <1179828041.761272.152380@x35g2000prf.googlegroups.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox