About the Greenplum Database Utilities

About the Greenplum Database Utilities

General information about using the Greenplum Database utility programs.

Referencing IP Addresses

When you reference IPv6 addresses in Greenplum Database utility programs, or when you use numeric IP addresses instead of hostnames in any management utility, always enclose the IP address in brackets. When specifying an IP address at the command line, the best practice is to escape any brackets or enclose them in single quotes. For example, use either:

\[2620:0:170:610::11\]

Or:

'[2620:0:170:610::11]'

Running Backend Server Programs

Greenplum Database has modified certain PostgreSQL backend server programs to handle the parallelism and distribution of a Greenplum Database system. You access these programs only through the Greenplum Database management tools and utilities. Do not run these programs directly.

The following table identifies certain PostgreSQL backend server programs and the Greenplum Database utility command to run instead.

Table 1. Greenplum Database Backend Server Programs
PostgreSQL Program Name Description Use Instead
initdb This program is called by gpinitsystem when initializing a Greenplum Database array. It is used internally to create the individual segment instances and the master instance. gpinitsystem
ipcclean Not used in Greenplum Database N/A
pg_basebackup This program makes a binary copy of a single database instance. Greenplum Database uses it for tasks such as creating a standby master instance, or recovering a mirror segment when a full copy is needed. Do not use this utility to back up Greenplum Database segment instances because it does not produce MPP-consistent backups. gpinitstandby, gprecoverseg
pg_controldata Not used in Greenplum Database gpstate
pg_ctl This program is called by gpstart and gpstop when starting or stopping a Greenplum Database array. It is used internally to stop and start the individual segment instances and the master instance in parallel and with the correct options. gpstart, gpstop
pg_resetxlog DO NOT USE

Warning: This program might cause data loss or cause data to become unavailable. If this program is used, the cluster must be reinitialized and restored.

N/A
postgres The postgres executable is the actual PostgreSQL server process that processes queries. The main postgres process (postmaster) creates other postgres subprocesses and postgres session as needed to handle client connections.
postmaster postmaster starts the postgres database server listener process that accepts client connections. In Greenplum Database, a postgres database listener process runs on the Greenplum master Instance and on each Segment Instance. In Greenplum Database, you use gpstart and gpstop to start all postmasters (postgres processes) in the system at once in the correct order and with the correct options.