Name
read_log — reads Virtuoso log
Synopsis
read_log
(
|
in file varchar , |
in
pos
integer
) ; |
Description
The
read_log
function reads from the Virtuoso Transactions log file from a given position.
Parameters
file
Virtuoso transaction log file.
pos
A given position from which the read to start from.
Return Types
The function returns array of transaction values.
Examples
Example 24.211. Sample example
-- 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