pgestraier/trunk/README.pod

=head1 pgestraier - search Hyper Estraier indexes from PostgreSQL

This package is essentially PostgreSQL C function which calls Hyper Estraier
API and returns results in user defined format.

=head1 Why is it written?

Aside from providing single API to query your RDBMS and full text index
(using any language that has PostgreSQL client libraries), real power is
hidden in ability to join results from full text index and structured data
in RDBMS.

=head1 How to install

Installation should be simple. However, you will have to have following
software already installed before you try this function:

=over

=item *

PostgreSQL (tested with versions 7.4 and 8.0) with development libraries

=item *

Hyper Estraier (version 0.5.0 or newer)

=back

To run tests you will also need:

=over

=item *

working perl installation

=item *

perl modules C<DBI>, C<DBD::Pg>, C<Test::More> and optionally C<HyperEstraier>

=item *

C<trivia.list.gz> from Internet Movie Database in data/ directory

=item *

PostgreSQL database C<test> with permissions for current user

=item *

Hyper Estraier node C<trivia> with permissions for C<admin> user.

=back

If you have all that, you should be able to type

  make

and see sample results. You will be asked your password once (via sudo) to
install C<pgest.so> shared library in system-wide location so that PostgreSQL
could access it.

Next, you will have to create test index. You have two options:

=head2 Create index using estcmd

This will create temporary files on disk and index them using estcmd gather

  cd data
  make index
  cd ..

B<Warning:> this method is incomplete and won't create node index needed
to run last examples in C<test.sql> correctly. Solution is simple: either
symlink your newly created index to Hyper Estraier C<_node> directory or
create node and fill re-create index using C<estcall>.

=head2 Create index using Hyper Estraier perl bindings

For this, you will have to install perl bindings from

L<http://hyperestraier.sourceforge.net/binding/>

If you installed bindings as documented in README file, you can use
perl binding to create index about three times faster than using C<estcmd>
(to be fair, I must say that creation of intermediate files take most time,
not indexing).

However, you will first need to create node I<trivia> using Hyper Estraier's
administration interface at L<http://localhost:1978/masterui>. You will also
need user C<admin> with password C<admin> because those values are
hard-coded in C<indexer.pl>. If you want to use different user on index
name, feel free to change script.

  cd data
  make perl
  cd ..

To run tests (which require that you have estcmd in your $PATH) issue

  make test

See also included file test.sql for more examples of usage.

=head1 Usage of pgest from SQL

C<pgest> PostgreSQL function has two different prototypes (number of arguments) depending on usage.

        SELECT
                -- columns to return (defined later)
                id,title,size
        FROM pgest(
                -- path to index OR URL to node, user-name and password
                -- you will need JUST ONE of following two lines, depending
                -- on your usage described below
                '/full/path/to/casket',
                'http://localhost:1978/node/trivia', 'admin', 'admin',
                -- query
                'blade runner',
                -- additional attributes, use NULL or '' to disable
                -- multiple attributes conditions can be separated by {{!}}
                '@title ISTRINC blade',
                -- order results by
                '@title STRA',
                -- limit, use NULL or 0 to disable
                null,
                -- offset, use NULL or 0 to disable
                null,
                -- attributes to return as columns
                ARRAY['@id','@title','@size']
        ) AS (
                -- specify names and types of returned attributes
                id text, title text, size text
        );

=head2 Accessing database directly

If you want to access database directly (without running C<estmaster> process), first argument is full path to database file.

Have in mind that C<postgres> user under which PostgreSQL is running must
have read permission on Hyper Estraier database files.

This will work a bit faster on really small indexes. However, when your
index grows bigger, you might consider using node API to remove overhead of
database opening on each query.

=head2 Using index via C<estmaster> server process

If first argument is URL to node (like C<http://localhost:1978/node/trivia>)
and there are two additional parameters (user-name and password) after it,
C<pgest> will use node API and access index through C<estmaster> process which should be running on (local or remote) machine.

This will remove database opening overhead, at a cost of additional network
traffic. However, you can have Hyper Estraier C<estmaster> process running on
different machine or update index while doing searches, so benefits of this
approach are obvious.

B<Note:> Currently, there is no support to search more than one index (depth
of search is always 0). This will be fixed.

=head1 Who wrote this?

Hyper Estraier is written by Mikio Hirabayashi.

Perl bindings for Hyper Estraier are written by MATSUNO Tokuhiro.

PostgreSQL is written by hackers calling themselves PostgreSQL Global
Development Group.

This small C function is written by Dobrica Pavlinusic, dpavlin@rot13.org.
1	dpavlin	33	=head1 pgestraier - search Hyper Estraier indexes from PostgreSQL
2	dpavlin	23
3			This package is essentially PostgreSQL C function which calls Hyper Estraier
4			API and returns results in user defined format.
5
6	dpavlin	33	=head1 Why is it written?
7	dpavlin	23
8			Aside from providing single API to query your RDBMS and full text index
9			(using any language that has PostgreSQL client libraries), real power is
10			hidden in ability to join results from full text index and structured data
11			in RDBMS.
12
13	dpavlin	33	=head1 How to install
14	dpavlin	23
15			Installation should be simple. However, you will have to have following
16			software already installed before you try this function:
17
18	dpavlin	33	=over
19	dpavlin	23
20	dpavlin	33	=item *
21
22	dpavlin	43	PostgreSQL (tested with versions 7.4 and 8.0) with development libraries
23	dpavlin	33
24			=item *
25
26	dpavlin	43	Hyper Estraier (version 0.5.0 or newer)
27	dpavlin	33
28			=back
29
30	dpavlin	23	To run tests you will also need:
31
32	dpavlin	33	=over
33	dpavlin	23
34	dpavlin	33	=item *
35
36			working perl installation
37
38			=item *
39
40			perl modules C<DBI>, C<DBD::Pg>, C<Test::More> and optionally C<HyperEstraier>
41
42			=item *
43
44			C<trivia.list.gz> from Internet Movie Database in data/ directory
45
46			=item *
47
48	dpavlin	43	PostgreSQL database C<test> with permissions for current user
49	dpavlin	33
50	dpavlin	43	=item *
51
52			Hyper Estraier node C<trivia> with permissions for C<admin> user.
53
54	dpavlin	33	=back
55
56	dpavlin	23	If you have all that, you should be able to type
57
58			make
59
60			and see sample results. You will be asked your password once (via sudo) to
61	dpavlin	43	install C<pgest.so> shared library in system-wide location so that PostgreSQL
62	dpavlin	23	could access it.
63
64	dpavlin	29	Next, you will have to create test index. You have two options:
65
66	dpavlin	33	=head2 Create index using estcmd
67	dpavlin	29
68			This will create temporary files on disk and index them using estcmd gather
69
70			cd data
71			make index
72			cd ..
73
74	dpavlin	42	B<Warning:> this method is incomplete and won't create node index needed
75			to run last examples in C<test.sql> correctly. Solution is simple: either
76			symlink your newly created index to Hyper Estraier C<_node> directory or
77			create node and fill re-create index using C<estcall>.
78
79	dpavlin	33	=head2 Create index using Hyper Estraier perl bindings
80	dpavlin	29
81			For this, you will have to install perl bindings from
82
83	dpavlin	42	L<http://hyperestraier.sourceforge.net/binding/>
84	dpavlin	29
85	dpavlin	42	If you installed bindings as documented in README file, you can use
86	dpavlin	43	perl binding to create index about three times faster than using C<estcmd>
87			(to be fair, I must say that creation of intermediate files take most time,
88			not indexing).
89	dpavlin	29
90	dpavlin	43	However, you will first need to create node I<trivia> using Hyper Estraier's
91			administration interface at L<http://localhost:1978/masterui>. You will also
92			need user C<admin> with password C<admin> because those values are
93			hard-coded in C<indexer.pl>. If you want to use different user on index
94			name, feel free to change script.
95
96	dpavlin	29	cd data
97			make perl
98			cd ..
99
100	dpavlin	23	To run tests (which require that you have estcmd in your $PATH) issue
101
102			make test
103
104			See also included file test.sql for more examples of usage.
105
106	dpavlin	42	=head1 Usage of pgest from SQL
107
108			C<pgest> PostgreSQL function has two different prototypes (number of arguments) depending on usage.
109
110			SELECT
111			-- columns to return (defined later)
112			id,title,size
113			FROM pgest(
114			-- path to index OR URL to node, user-name and password
115			-- you will need JUST ONE of following two lines, depending
116			-- on your usage described below
117			'/full/path/to/casket',
118			'http://localhost:1978/node/trivia', 'admin', 'admin',
119			-- query
120			'blade runner',
121			-- additional attributes, use NULL or '' to disable
122			-- multiple attributes conditions can be separated by {{!}}
123			'@title ISTRINC blade',
124			-- order results by
125			'@title STRA',
126			-- limit, use NULL or 0 to disable
127			null,
128			-- offset, use NULL or 0 to disable
129			null,
130			-- attributes to return as columns
131			ARRAY['@id','@title','@size']
132			) AS (
133			-- specify names and types of returned attributes
134			id text, title text, size text
135			);
136
137			=head2 Accessing database directly
138
139			If you want to access database directly (without running C<estmaster> process), first argument is full path to database file.
140
141			Have in mind that C<postgres> user under which PostgreSQL is running must
142			have read permission on Hyper Estraier database files.
143
144			This will work a bit faster on really small indexes. However, when your
145			index grows bigger, you might consider using node API to remove overhead of
146			database opening on each query.
147
148			=head2 Using index via C<estmaster> server process
149
150			If first argument is URL to node (like C<http://localhost:1978/node/trivia>)
151			and there are two additional parameters (user-name and password) after it,
152			C<pgest> will use node API and access index through C<estmaster> process which should be running on (local or remote) machine.
153
154			This will remove database opening overhead, at a cost of additional network
155			traffic. However, you can have Hyper Estraier C<estmaster> process running on
156			different machine or update index while doing searches, so benefits of this
157			approach are obvious.
158
159			B<Note:> Currently, there is no support to search more than one index (depth
160			of search is always 0). This will be fixed.
161
162	dpavlin	33	=head1 Who wrote this?
163	dpavlin	23
164			Hyper Estraier is written by Mikio Hirabayashi.
165
166	dpavlin	42	Perl bindings for Hyper Estraier are written by MATSUNO Tokuhiro.
167
168	dpavlin	23	PostgreSQL is written by hackers calling themselves PostgreSQL Global
169			Development Group.
170
171			This small C function is written by Dobrica Pavlinusic, dpavlin@rot13.org.