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 (tested with 0.5.0-1.0.0+, version newer than 0.9.6 are
recommended)

=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 C<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

Perl bindings for Hyper Estraier are available at

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

However, they don't support node API (yet), so you will have to use
my modified version which is available at
L<http://svn.rot13.org/> in C<hyperestraier_wrappers> repository.

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, for direct access
                '/full/path/to/casket',
                -- or for node API specify node URI, login, password
                -- and depth of search
                'http://localhost:1978/node/trivia', 'admin', 'admin', 42,
                -- 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.

=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	=head1 pgestraier - search Hyper Estraier indexes from PostgreSQL
2
3	This package is essentially PostgreSQL C function which calls Hyper Estraier
4	API and returns results in user defined format.
5
6	=head1 Why is it written?
7
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	=head1 How to install
14
15	Installation should be simple. However, you will have to have following
16	software already installed before you try this function:
17
18	=over
19
20	=item *
21
22	PostgreSQL (tested with versions 7.4 and 8.0) with development libraries
23
24	=item *
25
26	Hyper Estraier (tested with 0.5.0-1.0.0+, version newer than 0.9.6 are
27	recommended)
28
29	=back
30
31	To run tests you will also need:
32
33	=over
34
35	=item *
36
37	working perl installation
38
39	=item *
40
41	perl modules C<DBI>, C<DBD::Pg>, C<Test::More> and optionally C<HyperEstraier>
42
43	=item *
44
45	C<trivia.list.gz> from Internet Movie Database in C<data/> directory
46
47	=item *
48
49	PostgreSQL database C<test> with permissions for current user
50
51	=item *
52
53	Hyper Estraier node C<trivia> with permissions for C<admin> user.
54
55	=back
56
57	If you have all that, you should be able to type
58
59	make
60
61	and see sample results. You will be asked your password once (via sudo) to
62	install C<pgest.so> shared library in system-wide location so that PostgreSQL
63	could access it.
64
65	Next, you will have to create test index. You have two options:
66
67	=head2 Create index using estcmd
68
69	This will create temporary files on disk and index them using estcmd gather
70
71	cd data
72	make index
73	cd ..
74
75	B<Warning:> this method is incomplete and won't create node index needed
76	to run last examples in C<test.sql> correctly. Solution is simple: either
77	symlink your newly created index to Hyper Estraier C<_node> directory or
78	create node and fill re-create index using C<estcall>.
79
80	=head2 Create index using Hyper Estraier perl bindings
81
82	Perl bindings for Hyper Estraier are available at
83
84	L<http://hyperestraier.sourceforge.net/binding/>
85
86	However, they don't support node API (yet), so you will have to use
87	my modified version which is available at
88	L<http://svn.rot13.org/> in C<hyperestraier_wrappers> repository.
89
90	If you installed bindings as documented in README file, you can use
91	perl binding to create index about three times faster than using C<estcmd>
92	(to be fair, I must say that creation of intermediate files take most time,
93	not indexing).
94
95	However, you will first need to create node I<trivia> using Hyper Estraier's
96	administration interface at L<http://localhost:1978/masterui>. You will also
97	need user C<admin> with password C<admin> because those values are
98	hard-coded in C<indexer.pl>. If you want to use different user on index
99	name, feel free to change script.
100
101	cd data
102	make perl
103	cd ..
104
105	To run tests (which require that you have estcmd in your $PATH) issue
106
107	make test
108
109	See also included file test.sql for more examples of usage.
110
111	=head1 Usage of pgest from SQL
112
113	C<pgest> PostgreSQL function has two different prototypes (number of arguments) depending on usage.
114
115	SELECT
116	-- columns to return (defined later)
117	id,title,size
118	FROM pgest(
119	-- path to index OR URL to node, user-name and password
120	-- you will need JUST ONE of following two lines, depending
121	-- on your usage described below, for direct access
122	'/full/path/to/casket',
123	-- or for node API specify node URI, login, password
124	-- and depth of search
125	'http://localhost:1978/node/trivia', 'admin', 'admin', 42,
126	-- query
127	'blade runner',
128	-- additional attributes, use NULL or '' to disable
129	-- multiple attributes conditions can be separated by {{!}}
130	'@title ISTRINC blade',
131	-- order results by
132	'@title STRA',
133	-- limit, use NULL or 0 to disable
134	null,
135	-- offset, use NULL or 0 to disable
136	null,
137	-- attributes to return as columns
138	ARRAY['@id','@title','@size']
139	) AS (
140	-- specify names and types of returned attributes
141	id text, title text, size text
142	);
143
144	=head2 Accessing database directly
145
146	If you want to access database directly (without running C<estmaster> process), first argument is full path to database file.
147
148	Have in mind that C<postgres> user under which PostgreSQL is running must
149	have read permission on Hyper Estraier database files.
150
151	This will work a bit faster on really small indexes. However, when your
152	index grows bigger, you might consider using node API to remove overhead of
153	database opening on each query.
154
155	=head2 Using index via C<estmaster> server process
156
157	If first argument is URL to node (like C<http://localhost:1978/node/trivia>)
158	and there are two additional parameters (user-name and password) after it,
159	C<pgest> will use node API and access index through C<estmaster> process which should be running on (local or remote) machine.
160
161	This will remove database opening overhead, at a cost of additional network
162	traffic. However, you can have Hyper Estraier C<estmaster> process running on
163	different machine or update index while doing searches, so benefits of this
164	approach are obvious.
165
166	=head1 Who wrote this?
167
168	Hyper Estraier is written by Mikio Hirabayashi.
169
170	Perl bindings for Hyper Estraier are written by MATSUNO Tokuhiro.
171
172	PostgreSQL is written by hackers calling themselves PostgreSQL Global
173	Development Group.
174
175	This small C function is written by Dobrica Pavlinusic, dpavlin@rot13.org.