Thread: How to know which queries are to be optimised?
Hello, my web application grows slower and slower over time. After some profiling I came to the conclusion that my SQL queries are the biggest time spenders (25 seconds). Obviously I need to optimise my queries and maybe introduce some new indexes. The problem is, that my application uses dynamic queries. I therefor can not determine what are the most common queries. I have used the postgresql logging ption before. Is there a tool to analyze the logfile for the most common and/or most time consuming queries? TIA Ulrich
On Wed, Aug 04, 2004 at 14:00:39 +0200, Ulrich Wisser <ulrich.wisser@relevanttraffic.se> wrote: This topic really belongs on the performance list. I have copied that list and set followups to go there and copy you. > > my web application grows slower and slower over time. After some > profiling I came to the conclusion that my SQL queries are the biggest > time spenders (25 seconds). Obviously I need to optimise my queries and > maybe introduce some new indexes. This sounds like you aren't doing proper maintainance. You need to be vacuuming with a large enough FSM setting. > The problem is, that my application uses dynamic queries. I therefor can > not determine what are the most common queries. > > I have used the postgresql logging ption before. Is there a tool to > analyze the logfile for the most common and/or most time consuming queries? You can log queries that run for at least a specified amount of time. This will be useful in finding what the long running queries are. You can then use explain analyse to see why they are long running.
Hello, My linux admin left the job. We had a PostgreSQL installed under his username. He used to maintain it. Now I am looking at the Linux box and I am just a super duper newbie in Linux administration. The previosu admin had a database created under his name coz PostgreSQL dosnt allow root database. Now I want to get the data back and use it? I dont mind if I have to use a different DB? I dont even know where he isntalled the PostgreSQL binaries and data? Where can I all this information? I am feeling really stupid but thank GOD we dont have any live databases running? Regards, Karam __________________________________ Do you Yahoo!? Yahoo! Mail - Helps protect you from nasty viruses. http://promotions.yahoo.com/new_mail
All of the resources you need are at http://www.posgresql.org/ But, a quick note on how to connect to the database, you don't need to really know where it's installed, just that it's running and accepting connections. Under Linux "netstat -tapn" will show you all of the open TCP ports and what's listening to each. For Postgres, the default port is 5432 and the process is called postmaster. You may need to be logged in as root to see this. First thing is that knowing SQL basics is pretty much required before you can really investigate what he had set up. Second thing is to connect by using the following command: psql Without any arguments, it will connect to the local machine and to a database named for the current user. Once in psql, type \d to see a list of the user-defined tables. To see a list of databases type \l and you will be shown a list of databases. From there, you can explore until your heart's content. Everything is SQL compliant, so if you know SQL, you shouldn't have any problems. As for Linux admin, the most important thing to remember is that everything is case sensitive. ls != LS If you're coming from the MS world, take some time to really learn Linux... I'm sure you'll like it and eventually you'll prefer it. I use Linux as my only OS at home, and I finally have a job where I use Linux at work (they adopted it after I submitted a proposal). hope this helps! Laura Karam Chand wrote: >Hello, > >My linux admin left the job. We had a PostgreSQL >installed under his username. He used to maintain it. >Now I am looking at the Linux box and I am just a >super duper newbie in Linux administration. > >The previosu admin had a database created under his >name coz PostgreSQL dosnt allow root database. > >Now I want to get the data back and use it? I dont >mind if I have to use a different DB? > >I dont even know where he isntalled the PostgreSQL >binaries and data? > >Where can I all this information? > >I am feeling really stupid but thank GOD we dont have >any live databases running? > >Regards, >Karam > > -- Thanks, Laura Vance Systems Engineer Winfree Academy Charter Schools 6221 Riverside Dr. Ste 110 Irving, Tx 75039 Web: www.winfreeacademy.com