1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
<?xml version="1.0" encoding="ISO-8859-1"?>
<!--
-
- This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
- project.
-
- Copyright (C) 1998-2018 OpenLink Software
-
- This project is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by the
- Free Software Foundation; only version 2 of the License, dated June 1991.
-
- This program is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
-
- You should have received a copy of the GNU General Public License along
- with this program; if not, write to the Free Software Foundation, Inc.,
- 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-
-
-->
<refentry id="fn_read_log">
<refmeta>
<refentrytitle>read_log</refentrytitle>
<refmiscinfo>admin</refmiscinfo>
</refmeta>
<refnamediv>
<refname>read_log</refname>
<refpurpose>reads Virtuoso log</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis id="fsyn_read_log">
<funcprototype id="fproto_read_log">
<funcdef><function>read_log</function></funcdef>
<paramdef>in <parameter>file</parameter> varchar</paramdef>
<paramdef>in <parameter>pos</parameter> integer</paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1 id="desc_read_log"><title>Description</title>
<para>The <function>read_log</function> function reads from the Virtuoso Transactions log file from a given position.
</para>
</refsect1>
<refsect1 id="params_read_log">
<title>Parameters</title>
<refsect2><title>file</title>
<para>Virtuoso transaction log file.</para>
</refsect2>
<refsect2><title>pos</title>
<para>A given position from which the read to start from.</para>
</refsect2>
</refsect1>
<refsect1 id="ret_read_log"><title>Return Types</title>
<para>The function returns array of transaction values.</para>
</refsect1>
<refsect1 id="examples_read_log">
<title>Examples</title>
<example id="ex_read_log"><title>Sample example</title>
<screen><![CDATA[
-- insert sample data so to change the rdf_quad index:
SQL> SPARQL INSERT INTO <g> { <s> <p> <o> };
-- create the following example procedure
SQL>
create procedure rlt (in f any, in inpos int := 0)
{
declare h, op, g, s, p, o any;
declare pos int;
result_names (op, g, s, p, o);
h := file_open (f, inpos);
declare r, rr any;
while ((rr := read_log (h, pos)) is not null)
{
declare rw, k any;
declare i int;
rw := null;
k := null;
for (i := 1; i < length (rr); i := i + 1)
{
r := rr[i];
if (r[0] = 13) -- key insert
{
rw := r[2];
op := 'I';
}
else if (r[0] in (1,8,9)) -- insert,soft,replacing
{
rw := r[1];
op := 'I';
}
else if (r[0] in (3,14)) -- delete
{
rw := r[1];
op := 'D';
}
if (rw is not null)
{
k := rw[0];
if (k = 273) -- RDF_QUAD, should check with SYS_KEYS
{
result (op, __ro2sq (rw[1]), __ro2sq (rw[2]), __ro2sq (rw[3]), __ro2sq (rw[4]));
}
}
}
}
result (pos + inpos, '', '', '', '');
}
;
-- Call the procedure:
-- in case of no changes to the rdf_quad index are done, it will return:
SQL> rlt('tmp/Virtuoso.trx');
Query result:
op g s p o
ANY ANY ANY ANY ANY
8403
No. of rows in result: 1
-- in case of changes to the rdf_quad index are done ( example with the short INSERT we did above), it will return for example:
SQL> rlt('tmp/Virtuoso.trx');
Query result:
op g s p o
ANY ANY ANY ANY ANY
I g s p o
71446
No. of rows in result: 2
]]>
</screen>
</example>
</refsect1>
<refsect1 id="seealso_read_log"><title>See Also</title>
<para><link linkend="fn_log_enable"><function>log_enable</function></link></para>
<para><link linkend="fn_log_text"><function>log_text</function></link></para>
<para><link linkend="fn_log"><function>log</function></link></para>
<para><link linkend="fn_log10"><function>log10</function></link></para>
</refsect1>
</refentry>
|
