'\"macro stdmacro
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.TH PMFETCHARCHIVE 3 "PCP" "Performance Co-Pilot"
.SH NAME
\f3pmFetchArchive\f1 \- get performance metrics directly from a set if archive logs
.SH "C SYNOPSIS"
.ft 3
#include <pcp/pmapi.h>
.sp
int pmFetchArchive(pmResult **\fIresult\fP);
.sp
cc ... \-lpcp
.ft 1
.SH DESCRIPTION
.B pmFetchArchive
is a variant of 
.BR pmFetch (3)
that may only be used when the current
Performance Metrics Application Programming Interface (PMAPI)
context
is associated with a set of archive logs.
.PP
The
.I result
is instantiated with all of the metrics (and instances)
from the next archive record,
consequently there is no notion of a list of desired metrics,
and the instance profile of the PMAPI context is ignored.
.PP
.B pmFetchArchive
may return a
.I result
in which
.I numpmid
is zero.  This is a
.I <mark>
record that indicates a temporal discontinuity in the time series
of performance metrics.  This can happen at the boundary between archive logs
in a set
or if the archive log associated
with the current PMAPI context was created using
.BR pmlogextract (1)
to concatenate two or more PCP archive logs, and the
.I <mark>
record marks a point in time between the end of one input archive and
the start of the next input archive.
.PP
It is expected that 
.B pmFetchArchive
would be used to create utilities that scan sets of archive logs,
while the more common access to the archives would be via the 
.BR pmFetch (3)
interface.
.PP
To skip records within the set of archive logs, use
.BR pmSetMode (3)
to change the collection time within the current
PMAPI context, then call
.BR pmFetchArchive.
.PP
Note that the
.I result
returned by
.B pmFetchArchive
is dynamically allocated, and
must be released using
.BR pmFreeResult (3),
not
.BR free (3).
See
.BR pmFetch (3)
and
.BR pmFreeResult (3)
for further details.
.PP
.B pmFetchArchive
returns zero on success.
.SH SEE ALSO
.BR PMAPI (3),
.BR pmFetch (3),
.BR pmFreeResult (3),
.BR pmNewContext (3),
.BR pmSetMode (3)
and
.BR pmTrimNameSpace (3).
.SH DIAGNOSTICS
.IP \f3PM_ERR_NOTARCHIVE\f1
the current PMAPI context is not associated with a set of archive logs