</term>

<listitem>

<para>

Specifies the maximum amount of disk space that asession can use

Specifies the maximum amount of disk space that aprocess can use

for temporary files, such as sort and hash temporary files, or the

storage file for a held cursor. A transaction attempting to exceed

this limit will be canceled.

</para>

<para>

This setting constrains the total space used at any instant by all

temporary files used by a given <productname>PostgreSQL</>session.

temporary files used by a given <productname>PostgreSQL</>process.

It should be noted that disk space used for explicit temporary

tables, as opposed to temporary files used behind-the-scenes in query

execution, does <emphasis>not</emphasis> count against this limit.

be inefficient. The default value is 2. Setting this value to 0

disables parallel query execution.

</para>

<para>

Note that parallel queries may consume very substantially more

resources than non-parallel queries, because each worker process is

a completely separate process which has roughly the same impact on the

system as an additional user session. This should be taken into

account when choosing a value for this setting, as well as when

configuring other settings that control resource utilization, such

as <xref linkend="guc-work-mem">. Resource limits such as

<varname>work_mem</> are applied individually to each worker,

which means the total utilization may be much higher across all

processes than it would normally be for any single process.

For example, a parallel query using 4 workers may use up to 5 times

as much CPU time, memory, I/O bandwidth, and so forth as a query which

uses no workers at all.

</para>

</listitem>

</varlistentry>

{

{"temp_file_limit",PGC_SUSET,RESOURCES_DISK,

gettext_noop("Limits the total size of all temporary files used by eachsession."),

gettext_noop("Limits the total size of all temporary files used by eachprocess."),

gettext_noop("-1 means no limit."),

},

# - Disk -

#temp_file_limit = -1# limits per-session temp file space

#temp_file_limit = -1# limits per-process temp file space

# in kB, or -1 for no limit

# - Kernel Resource Usage -