Re: Compared MS SQL 2000 to Postgresql 9.0 on Windows - Mailing list pgsql-performance

What I was really after was a quick comparison between the two.  I did not
create anything special, just the two tables.  One table SQL generated the
records for me.  I did not tweak anything after installing either system.
There was a primary key on the ID field of both tables, no indexes though
in either system.  The second table had 1 record in it.  The hardware it
is running on is fairly good, dual Xeon CPUs, 4 GB of RAM, Raid 5.  Btw,
the cost for MS SQL 2008 R2 is ~$14,000 for 2 cpus,
http://www.cdw.com/shop/products/default.aspx?EDC=2167810 .  That is why I
am pursuing this.  :)

Here is the ASP.net code that I was running
Dim starttime As Date = Date.Now
        Dim endtime As Date
        Dim reader As NpgsqlDataReader
        Dim output2 As String = ""


        Dim oConn As New
NpgsqlConnection("Server=192.168.1.5;Port=5432;Userid=postgres;Password=12
345;Protocol=3;SSL=false;Pooling=true;MinPoolSize=1;MaxPoolSize=20;Encodin
g=UNICODE;Timeout=15;SslMode=Disable;Database=tomtemp")
        oConn.Open()
        Dim x As Integer = 0
        'For x = 0 To 1000 'uncomment to insert records.
        'Dim command As New NpgsqlCommand("insert into pgtemp1(name,
address, city, state) values ('Tom" & x & "','123" & x & " main
st','rockford',1) ", oConn) 'meant for loop to put in 1,000 records in
pgtemp1 table
        'Dim command As New NpgsqlCommand("insert into pgtemp2(statename,
stateid, other) values ('Illinois',1,'This is a lot of fun') ", oConn)
'only sends 1 record into the table pgtemp2
        'command.ExecuteNonQuery()
        'Next

        'join table and read 1000 rows.
        Dim command As New NpgsqlCommand("select
name,address,city,state,statename,stateid,other from pgtemp1 left join
pgtemp2 on state=stateid", oConn)
        reader = command.ExecuteReader()
        While reader.read()
            output2 += "<tr><td>" & reader("name") & "</td><td>" &
reader("address") & "</td><td>" & reader("city") & "</td><td>" &
reader("statename") & "</td><td>" & reader("other") & "</td></tr>"
        End While
        oConn.Close()
        readeroutput.text =
"<table><tr><td>Name:</td><td>Address:</td><td>City:</td><td>State</td><td
>Other</td></tr>" & output2 & "</table>"

        endtime = Date.Now
        Dim runtime As String
        runtime = endtime.Subtract(starttime).TotalSeconds
        output.text = starttime.ToString & " " & runtime

The SQL is a straight convert from MS SQL code.  I did not tweak either
system.

From EXPLAIN ANALYZE I can see the query ran much faster.
"Nested Loop Left Join  (cost=0.00..138.04 rows=1001 width=1298) (actual
time=0.036..4.679 rows=1001 loops=1)"
"  Join Filter: (pgtemp1.state = pgtemp2.stateid)"
"  ->  Seq Scan on pgtemp1  (cost=0.00..122.01 rows=1001 width=788)
(actual time=0.010..0.764 rows=1001 loops=1)"
"  ->  Materialize  (cost=0.00..1.01 rows=1 width=510) (actual
time=0.000..0.001 rows=1 loops=1001)"
"        ->  Seq Scan on pgtemp2  (cost=0.00..1.01 rows=1 width=510)
(actual time=0.006..0.008 rows=1 loops=1)"
"Total runtime: 5.128 ms"

The general question comes down to, can I expect decent perfomance from
Postgresql compared to MSSQL.  I was hoping that Postgresql 9.0 beat MSSQL
2000 since MS 2000 is over 10 years old.

Thanks,
Tom Polak
Rockford Area Association of Realtors
815-395-6776 x203

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-----Original Message-----
From: pgsql-performance-owner@postgresql.org
[mailto:pgsql-performance-owner@postgresql.org] On Behalf Of Andy Colson
Sent: Tuesday, December 07, 2010 2:23 PM
To: Kenneth Marshall
Cc: Richard Broersma; Justin Pitts; pgsql-performance@postgresql.org
Subject: Re: [PERFORM] Compared MS SQL 2000 to Postgresql 9.0 on Windows

On 12/7/2010 2:10 PM, Kenneth Marshall wrote:
> On Tue, Dec 07, 2010 at 11:56:51AM -0800, Richard Broersma wrote:
>> On Tue, Dec 7, 2010 at 11:43 AM, Andy Colson<andy@squeakycode.net>
wrote:
>>
>>> In PG the first statement you fire off (like an "insert into" for
example)
>>> will start a transaction. ?If you dont commit before you disconnect
that
>>> transaction will be rolled back. ?Even worse, if your program does not
>>> commit, but keeps the connection to the db open, the transaction will
stay
>>> open too.
>>
>> Huh - is this new?  I always thought that every statement was wrapped
>> in its own transaction unless you explicitly start your own.  So you
>> shouldn't need to commit before closing a connection if you never
>> opened a transaction to begin with.
>>
>>
>> --
>> Regards,
>> Richard Broersma Jr.
>>
>
> The default of autocommit unless explicitly starting a transaction with
> BEGIN is the normal behavior that I have seen as well.
>
> Cheers,
> Ken

Crikey!  You're right.  I need to be more careful with my assumptions.

I maintain that people need to be more careful with pg transactions.
I've seen several posts about "idle in transaction".  But its not as bad
as I made out.  My confusion comes from the library I use to hit PG,
which fires off a "begin" for me, and if I dont explicitly commit, it
gets rolled back.

sorry, it was confused between framework and PG.

-Andy

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