Thread: Poor performance with "large" table.
Subject: Poor performance with "large" table. From: "Jack Gao" <weigao@hotmail.com> === Hi, List I have two questions about PostgreSQL on Windows platform. I install postgresql 7.2.1 from cygwin. and running psql from cygwin also. 1. I'm keeping get error message when I use psql to get "large" data. For example, if one of my table has more than 74 records in it, when I run "select * from tbl...." on psql, it give me "less: not found" message. Also, if I run "\df" on psql, I got same message. But if I run "\df to_char", I got the inform I want. Looks like psql can not showing too much data. But what this error message mean, and how to fix it? 2. I have a table has about 208458 records in it, and I tried "vacuum analyze" on my database before I doing this test. When I run "explain select count(*) from tblTest;" it give me something like: ============================================================================ ======== NOTICE: QUERY PLAN: Aggregate (cost=4618.73..4618.73 rows=1 width=0) -> Seq Scan on tbltest (cost=0.00..4097.58 rows=208458 width=0) EXPLAIN ============================================================================ ======== and I got result in seconds. When I run "explain select * from tblTest;", it give me something like: ============================================================================ ======== NOTICE: QUERY PLAN: Seq Scan on tbltest (cost=0.00..4097.58 rows=208458 width=38) EXPLAIN ============================================================================ ======== But I got that error message after about 10 minutes. 200k record is not that large I think. Is it something wrong with my installation? I didn't got chance to test it on Linux platform yet, I will post the result after I do the same test on Linux platform. Thanks and regards, Jack
On Wed, 17 Apr 2002, pgsql-gen Newsgroup wrote: > 1. I'm keeping get error message when I use psql to get "large" data. For > example, if one of my table has more than 74 records in it, when I run > "select * from tbl...." on psql, it give me "less: not found" message. Also, > if I run "\df" on psql, I got same message. But if I run "\df to_char", I > got the inform I want. Looks like psql can not showing too much data. But > what this error message mean, and how to fix it? The frontend seems to use "less" (an improved "more") as a pager if more rows are returned than fit on one screen. Be sure to have "less" installed and in your PATH.
Subject: Re: [GENERAL] Poor performance with "large" table. From: "Jack Gao" <weigao@hotmail.com> === Thanks for the reply, it's really helped. Actually, after I installed less, I got another error message. "WARN: terminal is not fully function.....". And I found that because of Rational Rose, Rational Rose set envirement variable "TERM" to nutc, but cygwin need it to be "cygwin". Thanks again. Jack "Holger Marzen" <holger@marzen.de> wrote in message news:mailman.1019032861.29298.pgsql-gen@basebeans.com... > On Wed, 17 Apr 2002, pgsql-gen Newsgroup wrote: > > > 1. I'm keeping get error message when I use psql to get "large" data. For > > example, if one of my table has more than 74 records in it, when I run > > "select * from tbl...." on psql, it give me "less: not found" message. Also, > > if I run "\df" on psql, I got same message. But if I run "\df to_char", I > > got the inform I want. Looks like psql can not showing too much data. But > > what this error message mean, and how to fix it? > > The frontend seems to use "less" (an improved "more") as a pager if more > rows are returned than fit on one screen. Be sure to have "less" > installed and in your PATH. >