Database Technologies

1. pg_describe_object:  In PostgreSQL 9.1, pg_describe_object function has been added. Using this function, user can get human readable string for understanding the pg_depend content as given below: postgres=# select classid, objid, objsubid, pg_describe_object(classid, objid, objsubid) from pg_depend where classid <> 0 and pg_describe_object(classi classid | objid | objsubid | pg_describe_object ---------+-------+----------+------------------------------------------------ 1247 | 16426 | 0 | type test_money 1247 | 16425 | 0 | type test_money[] 1259 | 16424 | 0 | table test_money 1259 | 16429 | 0 | index test_money_idx 2606 | 16431 | 0 | constraint uniq_constraint on table test_money 2. quote_all_identifiers (boolean) parameter:  With this parameter, User can force quoating of all identifiers in EXMPLAIN and in system catalog functions like pg_get_viewdef(). Example is given below...

PostgreSQL 9.1 has come with new options and Improvement for Client Application. So, I thought to blog about those improvements.   Deprecated createlang/droplang: In PostgreSQL 9.1, createlang/dronlang is now deprecated commands. Since in PostgreSQL 9.1, for creating additional language, user has to use CREATE EXTENSION SYNTAX , there these binaries now issue command given below: CREATE EXTENSION plperl; CREATE EXTENSION plpyhthon; Added Features in psql: In PostgreSQL 9.1, following are the important improvement done in psql command:   1. Know about connection. Now psql has meta command \conninfo which gives detal about current connections. So, if you are connected to PostgreSQL database, then you can use command "\conninfo" to get detail about your connections, some example is given below: postgres=# \conninfo You are connected to database "postgres" as user "postgres" via socket in "/tmp" at port "5432". postgres=# \conni...

Since, PostgreSQL 9.1 has already been released and there are lot of new features added in it, so, I thought to blog about each features. Today, I am discussing about Synchronous and Asynchronous Replication supported in PostgreSQL 9.1. For Asynchronous Replication, user can use following method: 1. Change Following Parameters in postgresql.conf file of Primary Database: archive_command = cp -i %p /Users/postgres/archive/%f archive_mode = on max_wal_senders = 3 # Maximum 'wal_senders', processes responsible for managing a connection with a standby server wal_keep_segments = # How many WAL segments (=files) should be kept on the primary, whatever may happen (you won't have to copy them manually on the standby if the standby gets too far behind) wal_level = hot_standby 2. Make Following changes in pg_hba.conf host replication postgres [Ipv4 address of Standby Server]/32 trust host replication postgres [Ipv4 address of Master Server]/32 tr...

Today, I thought to share my Training slides on FTS (Full Text Search) in PostgreSQL 9.0. I have used this presentation on giving training. Enjoy :). Full Text Search Training

Depsez has Started a New project called Curo, which is currently made for Unix/Linux and is in initial phase. So, I thought to look at how it works and how normal user, who knows using psql, can benefit from it. Before Installing Curo, user has to make sure, he has postgreSQL client: psql and following package installed on his Linux/Unix System: 1. Bash 2. dialog If you have above required packages on your machine, then you can move for Curo installation. Curo Installation is very simple. Following are the steps which can be use to install Curo on Unix/Linux System: 1. Download the Curo from Following link: https://github.com/omniti-labs/curo Above link will give you file similar to given below: omniti-labs-curo-48a4f31.tar.gz 2. Untar the file using following command: tar -xvf omniti-labs-curo-48a4f31.tar.gz 3. Copy omniti-labs-curo-48a4f31 to users home directory as given below: cp omniti-labs-curo-48a4f31 ~/.curo 4. Now configure .inputrc and .editrc file as given...

I had seen people ask Questions about finding the edb-jdbc/postgresql driver version with Database Version. So, I thought to give one java script which can be use to find Database Details with edb-jdbc version. Following is a JAVA Code which can be use to find the Database Version and EDB-JDBC/postgresql-jdbc Version: File Name: DBinfo.java import java.sql.*; public class DBinfo { public static void main(String[] args) { try { Class.forName("com.edb.Driver"); Connection con = DriverManager.getConnection("jdbc:edb://localhost:5444/edb", "enterprisedb","edb"); // Advanced Server Database Connection Information DatabaseMetaData dbmd = con.getMetaData(); System.out.println("===== Database info ====="); System.out.println("DatabaseProductName: " + dbmd.getDatabaseProductName() ); System.out.println("DatabaseProductVersion: " + dbmd.getDatabaseProduc...

Logrotator is a small C program which is well written and available on most of the UNIX based OS. It allows automatic rotation, compression of logfiles and removal of old logfiles. This small file can be use to manage applications logfiles. It can also use for managing slony logfiles. For managing logfiles using logrotator user has to make a logrotator conf file, and can be scheduled in crontab for managing logile. Let see how you can make a logrotator configuration file for slony. I have slony master/slave daemon running on my slave maching has following location for slony logfiles: /opt/PostgresPlus/9.0AS/slony_test/slony1/node1 -- For master /opt/PostgresPlus/9.0AS/slony_test/slony1/node2 -- For slave. For managing logfile, user can make logrotator configuration file similar to given below: Configuration filename: /etc/logrotate.d/slonylogfiles "/opt/PostgresPlus/9.0AS/slony_test/slony1/node[12]/*.log" { rotate 5 mail vibhor.aim@gmail.com ...