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Linux 2.6 - man page for dbi::profiledata (linux section 3pm)

DBI::ProfileData(3pm)	       User Contributed Perl Documentation	    DBI::ProfileData(3pm)

NAME
       DBI::ProfileData - manipulate DBI::ProfileDumper data dumps

SYNOPSIS
       The easiest way to use this module is through the dbiprof frontend (see dbiprof for
       details):

	 dbiprof --number 15 --sort count

       This module can also be used to roll your own profile analysis:

	 # load data from dbi.prof
	 $prof = DBI::ProfileData->new(File => "dbi.prof");

	 # get a count of the records (unique paths) in the data set
	 $count = $prof->count();

	 # sort by longest overall time
	 $prof->sort(field => "longest");

	 # sort by longest overall time, least to greatest
	 $prof->sort(field => "longest", reverse => 1);

	 # exclude records with key2 eq 'disconnect'
	 $prof->exclude(key2 => 'disconnect');

	 # exclude records with key1 matching /^UPDATE/i
	 $prof->exclude(key1 => qr/^UPDATE/i);

	 # remove all records except those where key1 matches /^SELECT/i
	 $prof->match(key1 => qr/^SELECT/i);

	 # produce a formatted report with the given number of items
	 $report = $prof->report(number => 10);

	 # clone the profile data set
	 $clone = $prof->clone();

	 # get access to hash of header values
	 $header = $prof->header();

	 # get access to sorted array of nodes
	 $nodes = $prof->nodes();

	 # format a single node in the same style as report()
	 $text = $prof->format($nodes->[0]);

	 # get access to Data hash in DBI::Profile format
	 $Data = $prof->Data();

DESCRIPTION
       This module offers the ability to read, manipulate and format DBI::ProfileDumper profile
       data.

       Conceptually, a profile consists of a series of records, or nodes, each of each has a set
       of statistics and set of keys.  Each record must have a unique set of keys, but there is
       no requirement that every record have the same number of keys.

METHODS
       The following methods are supported by DBI::ProfileData objects.

   $prof = DBI::ProfileData->new(File => "dbi.prof")
   $prof = DBI::ProfileData->new(File => "dbi.prof", Filter => sub { ... })
   $prof = DBI::ProfileData->new(Files => [ "dbi.prof.1", "dbi.prof.2" ])
       Creates a a new DBI::ProfileData object.  Takes either a single file through the File
       option or a list of Files in an array ref.  If multiple files are specified then the
       header data from the first file is used.

       Files

       Reference to an array of file names to read.

       File

       Name of file to read. Takes precedence over "Files".

       DeleteFiles

       If true, the files are deleted after being read.

       Actually the files are renamed with a C.deleteme> suffix before being read, and then,
       after reading all the files, they're all deleted together.

       The files are locked while being read which, combined with the rename, makes it safe to
       'consume' files that are still being generated by DBI::ProfileDumper.

       Filter

       The "Filter" parameter can be used to supply a code reference that can manipulate the
       profile data as it is being read. This is most useful for editing SQL statements so that
       slightly different statements in the raw data will be merged and aggregated in the loaded
       data. For example:

	 Filter => sub {
	     my ($path_ref, $data_ref) = @_;
	     s/foo = '.*?'/foo = '...'/ for @$path_ref;
	 }

       Here's an example that performs some normalization on the SQL. It converts all numbers to
       "N" and all quoted strings to "S".  It can also convert digits to N within names. Finally,
       it summarizes long "IN (...)" clauses.

       It's aggressive and simplistic, but it's often sufficient, and serves as an example that
       you can tailor to suit your own needs:

	 Filter => sub {
	     my ($path_ref, $data_ref) = @_;
	     local $_ = $path_ref->[0]; # whichever element contains the SQL Statement
	     s/\b\d+\b/N/g;		# 42 -> N
	     s/\b0x[0-9A-Fa-f]+\b/N/g;	# 0xFE -> N
	     s/'.*?'/'S'/g;		# single quoted strings (doesn't handle escapes)
	     s/".*?"/"S"/g;		# double quoted strings (doesn't handle escapes)
	     # convert names like log_20001231 into log_NNNNNNNN, controlled by $opt{n}
	     s/([a-z_]+)(\d{$opt{n},})/$1.('N' x length($2))/ieg if $opt{n};
	     # abbreviate massive "in (...)" statements and similar
	     s!(([NS],){100,})!sprintf("$2,{repeated %d times}",length($1)/2)!eg;
	 }

       It's often better to perform this kinds of normalization in the DBI while the data is
       being collected, to avoid too much memory being used by storing profile data for many
       different SQL statement. See DBI::Profile.

   $copy = $prof->clone();
       Clone a profile data set creating a new object.

   $header = $prof->header();
       Returns a reference to a hash of header values.	These are the key value pairs included in
       the header section of the DBI::ProfileDumper data format.  For example:

	 $header = {
	   Path    => [ '!Statement', '!MethodName' ],
	   Program => 't/42profile_data.t',
	 };

       Note that modifying this hash will modify the header data stored inside the profile
       object.

   $nodes = $prof->nodes()
       Returns a reference the sorted nodes array.  Each element in the array is a single record
       in the data set.  The first seven elements are the same as the elements provided by
       DBI::Profile.  After that each key is in a separate element.  For example:

	$nodes = [
		   [
		     2, 		     # 0, count
		     0.0312958955764771,     # 1, total duration
		     0.000490069389343262,   # 2, first duration
		     0.000176072120666504,   # 3, shortest duration
		     0.00140702724456787,    # 4, longest duration
		     1023115819.83019,	     # 5, time of first event
		     1023115819.86576,	     # 6, time of last event
		     'SELECT foo FROM bar'   # 7, key1
		     'execute'		     # 8, key2
					     # 6+N, keyN
		   ],
					     # ...
		 ];

       Note that modifying this array will modify the node data stored inside the profile object.

   $count = $prof->count()
       Returns the number of items in the profile data set.

   $prof->sort(field => "field")
   $prof->sort(field => "field", reverse => 1)
       Sorts data by the given field.  Available fields are:

	 longest
	 total
	 count
	 shortest

       The default sort is greatest to smallest, which is the opposite of the normal Perl
       meaning.  This, however, matches the expected behavior of the dbiprof frontend.

   $count = $prof->exclude(key2 => "disconnect")
   $count = $prof->exclude(key2 => "disconnect", case_sensitive => 1)
   $count = $prof->exclude(key1 => qr/^SELECT/i)
       Removes records from the data set that match the given string or regular expression.  This
       method modifies the data in a permanent fashion - use clone() first to maintain the
       original data after exclude().  Returns the number of nodes left in the profile data set.

   $count = $prof->match(key2 => "disconnect")
   $count = $prof->match(key2 => "disconnect", case_sensitive => 1)
   $count = $prof->match(key1 => qr/^SELECT/i)
       Removes records from the data set that do not match the given string or regular
       expression.  This method modifies the data in a permanent fashion - use clone() first to
       maintain the original data after match().  Returns the number of nodes left in the profile
       data set.

   $Data = $prof->Data()
       Returns the same Data hash structure as seen in DBI::Profile.  This structure is not
       sorted.	The nodes() structure probably makes more sense for most analysis.

   $text = $prof->format($nodes->[0])
       Formats a single node into a human-readable block of text.

   $text = $prof->report(number => 10)
       Produces a report with the given number of items.

AUTHOR
       Sam Tregar <sam@tregar.com>

COPYRIGHT AND LICENSE
       Copyright (C) 2002 Sam Tregar

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl 5 itself.

perl v5.12.3				    2007-09-27			    DBI::ProfileData(3pm)


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