In addition to nf, a PostgreSQL data directory contains a file, which has the same format as nf but is intended to be edited automatically not manually. Invalid parameter settings in the configuration file are likewise ignored (but logged) during SIGHUP processing. Some parameters can only be set at server start any changes to their entries in the configuration file will be ignored until the server is restarted. Alternatively, you can send the signal to a single server process directly. The main server process also propagates this signal to all currently running server processes, so that existing sessions also adopt the new values (this will happen after they complete any currently-executing client command). The configuration file is reread whenever the main server process receives a SIGHUP signal this signal is most easily sent by running pg_ctl reload from the command line or by calling the SQL function pg_reload_conf(). The following sections describe ways in which the administrator or user can override these defaults. The settings seen by active sessions will be these values unless they are overridden. Parameters set in this way provide default values for the cluster. If the file contains multiple entries for the same parameter, all but the last one are ignored. To embed a single quote in a parameter value, write either two quotes (preferred) or backslash-quote. Parameter values that are not simple identifiers or numbers must be single-quoted. Hash marks ( #) designate the remainder of the line as a comment. Whitespace is insignificant (except within a quoted parameter value) and blank lines are ignored. The equal sign between name and value is optional. An example of what this file might look like is: # This is a comment A default copy is installed when the database cluster directory is initialized. The most fundamental way to set these parameters is to edit the file nf, which is normally kept in the data directory. Parameter Interaction via the Configuration File Enum parameter values are case-insensitive.ġ8.1.2. The values allowable for such a parameter can be found from pg_settings. Valid time units are ms (milliseconds), s (seconds), min (minutes), h (hours), and d (days).Įnumerated: Enumerated-type parameters are written in the same way as string parameters, but are restricted to have one of a limited set of values. The multiplier for memory units is 1024, not 1000. Valid memory units are kB (kilobytes), MB (megabytes), GB (gigabytes), and TB (terabytes). The unit name is case-sensitive, and there can be whitespace between the numeric value and the unit. Note that the value must be written as a string (with quotes) to use this feature. For convenience, settings can be given with a unit specified explicitly, for example '120 ms' for a time value, and they will be converted to whatever the parameter's actual unit is. An unadorned numeric value for one of these settings will use the setting's default unit, which can be learned from pg_settings. The unit might be kilobytes, blocks (typically eight kilobytes), milliseconds, seconds, or minutes. Numeric with Unit: Some numeric parameters have an implicit unit, because they describe quantities of memory or time. Numeric (integer and floating point): A decimal point is permitted only for floating-point parameters. Quotes can usually be omitted if the value is a simple number or identifier, however. String: In general, enclose the value in single quotes, doubling any single quotes within the value. The type determines the syntax for setting the parameter:īoolean: Values can be written as on, off, true, false, yes, no, 1, 0 (all case-insensitive) or any unambiguous prefix of one of these. Every parameter takes a value of one of five types: boolean, string, integer, floating point, or enumerated (enum). All parameter names are case-insensitive.

Postgresql commands 9.5