Re: Datatypes and performance

Wasn't any sarcasm in my words,
as I sad I am really glad to see real numbers behind the story about
no performance difference for varchar and text.

I do not have performance metrics for varchars,
but I have benchmarks and my observations about performance in general.
Just want to say, I haven't seen much other DBMS systems other then
Microsoft SQL,
and Postgres 7.3.x, so my performance observations based on those
systems.
Selects, do not have any problems in general equal or slightly slower
that MS SQL.

Inserts/Updates sometimes slow, sometimes a nightmare,
in general painfully slow.

I guess as long as Postgres retrieves data fast enough I satisfied,
but for dynamic DBs ( lots of inserts/updates ) ....

P.S
do not want to offend somebody or something, just saying what I see.


-----Original Message-----
From: Alvaro Herrera [mailto:alvherre@dcc.uchile.cl]
Sent: Friday, July 04, 2003 8:13 PM
To: Maksim Likharev
Cc: PostgreSQL List
Subject: Re: [GENERAL] Datatypes and performance


On Fri, Jul 04, 2003 at 06:57:04PM -0700, Maksim Likharev wrote:
> Ok, then if I store 4K - 1byte in a varchar and after that 4K + 1
byte,
> and again and again, you are saying me that my text will be jerking
> around 2 tables?

In any case the tuple will probably "jerk around" different pages (I
don't think it's different whether the pages are from two tables or from
the same one).  I fail to understand how that is a different performance
problem than for any other datatype.  I'm sure you've done some
benchmark to determine that the varchar handling is as slow as you
appear to be saying?

--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"Postgres is bloatware by design: it was built to house
PhD theses." (Joey Hellerstein, SIGMOD annual conference 2002)