From: 谭忠涛 <zhongtao.tan@seaboxdata.com>
To: pgsql-bugs <pgsql-bugs@lists.postgresql.org>
Subject: Performance Issue when using gin index
Date: Tue, 21 Jan 2025 10:30:24 +0800
Message-ID: <tencent_7773A0055A04795D1E3DB6E3@qq.com> (raw)
The performance of creating a gin index before inserting data is different from that of inserting data after creating a gin index.
Case:
-- first make pg_trgm
create extension pg_trgm;
create table t1(a int, b varchar(20));
create index t1_b on t1 using gin(b gin_trgm_ops);
insert into t1 select a, a || substr('abcdefg', (random()*100000)::int%10000, 10) || a from generate_series(1,100000) t(a);
analyze t1;
explain analyze select * from t1 where b like '%abc%'; -- slow
reindex index t1_b;
explain analyze select * from t1 where b like '%abc%'; -- normal
Regards
谭忠涛 数据研究院数据库事业部
北京东方金信科技股份有限公司
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To: pgsql-bugs@postgresql.org
Cc: zhongtao.tan@seaboxdata.com, pgsql-bugs@lists.postgresql.org
Subject: Re: Performance Issue when using gin index
In-Reply-To: <tencent_7773A0055A04795D1E3DB6E3@qq.com>
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