XMLIndex: finding indexed XPaths and the number of rows in the path table

Question

Hi,
I am storing non-schema-based binary XMLs in an XMLType column in 11g (11.1.0.6.0) and would like to index the XMLs either partially or fully using XMLIndex. I'm expecting to have a large number (tens of millions) of XML documents and have some concerns about the size of the XMLIndex path table.
In short, I am worried that the path table might grow unmanageable large. In order to avoid this and to plan for table partitioning, I would like to create a report of all indexed XPaths in an XMLIndex and to find out how many times each path is actualized in the path table. I would do this for a representative XML sample.
I have been creating XMLIndexes with different exclude/include paths, gathering stats with DBMS_STATS (estimate_percent = 100) and selecting the number of rows in the path table through USER_TABLES.
If anyone knows a more straightforward way of doing this all advice is very much appreciated.
Best Regards,
Rasko Leinonen

Answer 1

Thanks Marco,
I managed to get out all indexed paths using the following SQL. It took a while to understand how the join the XDB.X$PT39CW6BJR8W4VVE0G0LLGA0OCR5 and XDB.X$QN39CW6BJR8W4VVE0G0LLGA0OCR5 tables together but got there in the end. This helps to clarify which XPaths are being currently indexed by the XMLIndex.
begin
for v_row in (select PATH from XDB.X$PT39CW6BJR8W4VVE0G0LLGA0OCR5)
loop
declare
v_i BINARY_INTEGER := 1;
v_id raw(8);
v_len BINARY_INTEGER := 2;
v_skip BINARY_INTEGER := 1;
begin
while v_i < utl_raw.length(v_row.path) and
v_i + v_len <= utl_raw.length(v_row.path)
loop
v_i := v_i + v_skip;
v_id := utl_raw.substr(v_row.path, v_i, v_len);
--dbms_output.put_line(v_id);
for v_row2 in (select LOCALNAME, flags from XDB.X$QN39CW6BJR8W4VVE0G0LLGA0OCR5
where ID = v_id )
loop
if rawtohex(v_row2.flags) = '01'
then
dbms_output.put('@');
end if;
dbms_output.put(v_row2.localname);
if v_i + v_len < utl_raw.length(v_row.path)
then
dbms_output.put('/');
end if;
end loop;
v_i := v_i + v_len;
end loop;
dbms_output.put_line('');
end;
end loop;
end;
Example output:
RUN
RUN/@accession
RUN/@alias
RUN/@instrument_model
RUN/@run_date
RUN/@run_center
RUN/@total_data_blocks
RUN/EXPERIMENT_REF
RUN/EXPERIMENT_REF/@accession
RUN/EXPERIMENT_REF/@refname
RUN/DATA_BLOCK
RUN/DATA_BLOCK/@name
RUN/DATA_BLOCK/@total_spots
RUN/DATA_BLOCK/@total_reads
RUN/DATA_BLOCK/@number_channels
RUN/DATA_BLOCK/@format_code
RUN/DATA_BLOCK/@sector
RUN/DATA_BLOCK/FILES
RUN/DATA_BLOCK/FILES/FILE
RUN/DATA_BLOCK/FILES/FILE/@filename
RUN/DATA_BLOCK/FILES/FILE/@filetype
RUN/RUN_ATTRIBUTES
RUN/RUN_ATTRIBUTES/RUN_ATTRIBUTE
RUN/RUN_ATTRIBUTES/RUN_ATTRIBUTE/TAG
RUN/RUN_ATTRIBUTES/RUN_ATTRIBUTE/VALUE