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 version 7.4.8) with development libraries

=item *

Hyper Estraier (tested with versions 0.3.9 and 0.3.10)

=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 *

database "test" with permissions for current 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 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. However, you will
fist 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			PostgreSQL (tested with version 7.4.8) with development libraries
23
24			=item *
25
26			Hyper Estraier (tested with versions 0.3.9 and 0.3.10)
27
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			database "test" with permissions for current user
49
50			=back
51
52	dpavlin	23	If you have all that, you should be able to type
53
54			make
55
56			and see sample results. You will be asked your password once (via sudo) to
57			install pgest.so shared library in system-wide location so that PostgreSQL
58			could access it.
59
60	dpavlin	29	Next, you will have to create test index. You have two options:
61
62	dpavlin	33	=head2 Create index using estcmd
63	dpavlin	29
64			This will create temporary files on disk and index them using estcmd gather
65
66			cd data
67			make index
68			cd ..
69
70	dpavlin	42	B<Warning:> this method is incomplete and won't create node index needed
71			to run last examples in C<test.sql> correctly. Solution is simple: either
72			symlink your newly created index to Hyper Estraier C<_node> directory or
73			create node and fill re-create index using C<estcall>.
74
75	dpavlin	33	=head2 Create index using Hyper Estraier perl bindings
76	dpavlin	29
77			For this, you will have to install perl bindings from
78
79	dpavlin	42	L<http://hyperestraier.sourceforge.net/binding/>
80	dpavlin	29
81	dpavlin	42	If you installed bindings as documented in README file, you can use
82			perl binding to create index about three times faster. However, you will
83			fist need to create node I<trivia> using Hyper Estraier's administration
84			interface at L<http://localhost:1978/masterui>. You will also need user
85			C<admin> with password C<admin> because those values are hard-coded in
86			C<indexer.pl>. If you want to use different user on index name, feel
87			free to change script.
88	dpavlin	29
89			cd data
90			make perl
91			cd ..
92
93	dpavlin	23	To run tests (which require that you have estcmd in your $PATH) issue
94
95			make test
96
97			See also included file test.sql for more examples of usage.
98
99	dpavlin	42	=head1 Usage of pgest from SQL
100
101			C<pgest> PostgreSQL function has two different prototypes (number of arguments) depending on usage.
102
103			SELECT
104			-- columns to return (defined later)
105			id,title,size
106			FROM pgest(
107			-- path to index OR URL to node, user-name and password
108			-- you will need JUST ONE of following two lines, depending
109			-- on your usage described below
110			'/full/path/to/casket',
111			'http://localhost:1978/node/trivia', 'admin', 'admin',
112			-- query
113			'blade runner',
114			-- additional attributes, use NULL or '' to disable
115			-- multiple attributes conditions can be separated by {{!}}
116			'@title ISTRINC blade',
117			-- order results by
118			'@title STRA',
119			-- limit, use NULL or 0 to disable
120			null,
121			-- offset, use NULL or 0 to disable
122			null,
123			-- attributes to return as columns
124			ARRAY['@id','@title','@size']
125			) AS (
126			-- specify names and types of returned attributes
127			id text, title text, size text
128			);
129
130			=head2 Accessing database directly
131
132			If you want to access database directly (without running C<estmaster> process), first argument is full path to database file.
133
134			Have in mind that C<postgres> user under which PostgreSQL is running must
135			have read permission on Hyper Estraier database files.
136
137			This will work a bit faster on really small indexes. However, when your
138			index grows bigger, you might consider using node API to remove overhead of
139			database opening on each query.
140
141			=head2 Using index via C<estmaster> server process
142
143			If first argument is URL to node (like C<http://localhost:1978/node/trivia>)
144			and there are two additional parameters (user-name and password) after it,
145			C<pgest> will use node API and access index through C<estmaster> process which should be running on (local or remote) machine.
146
147			This will remove database opening overhead, at a cost of additional network
148			traffic. However, you can have Hyper Estraier C<estmaster> process running on
149			different machine or update index while doing searches, so benefits of this
150			approach are obvious.
151
152			B<Note:> Currently, there is no support to search more than one index (depth
153			of search is always 0). This will be fixed.
154
155	dpavlin	33	=head1 Who wrote this?
156	dpavlin	23
157			Hyper Estraier is written by Mikio Hirabayashi.
158
159	dpavlin	42	Perl bindings for Hyper Estraier are written by MATSUNO Tokuhiro.
160
161	dpavlin	23	PostgreSQL is written by hackers calling themselves PostgreSQL Global
162			Development Group.
163
164			This small C function is written by Dobrica Pavlinusic, dpavlin@rot13.org.