How to purge PERFSTAT.STATS$SQLTEXT table, after deleting snapshots

Question

I had an alarm on the free space of the PERFSTAT tablespace. In order to free up some space I tried to delete some old StatsPack snapshots, with the following query:
DELETE from perfstat.stats$snapshot where snap_time < sysdate - 10 ;
COMMIT;
After running it the space usage on the tablespace was not significantly reduced. I checked again and I saw that the table PERFSTAT.STATS$SQLTEXT was very big, almost 8 Gb, but all the other tables were a lot smaller. I read somewhere that the sppurge.sql procedure, that comes with Oracle, could be used to purge the statspack data, but that it comes with the lines related to PERFSTAT.STATS$SQLTEXT commented, because it is a big query and it can take a lot of undo space. I tried to run the followiung query, which I found in the forum, by Don Burleson, but it failed, because of running out of undo:
DELETE /*+ index_ffs(st)*/
FROM perfstat.stats$sqltext st
WHERE (hash_value, text_subset) NOT IN (
SELECT /*+ hash_aj full(ss) no_expand*/ hash_value, text_subset
FROM perfstat.stats$sql_summary ss
WHERE snap_id NOT IN (SELECT DISTINCT snap_id FROM perfstat.stats$snapshot)
COMMIT;
Is there any way to know if the PERFSTAT.STATS$SQLTEXT table has records that could be purged, and an easier way, that don't use as much undo, to purge it?
My oracle version is:
Oracle9i Enterprise Edition Release 9.2.0.7.0 - 64bit Production
PL/SQL Release 9.2.0.7.0 - Production
CORE 9.2.0.7.0 Production
TNS for Solaris: Version 9.2.0.7.0 - Production
NLSRTL Version 9.2.0.7.0 - Production
I. Neva
Oracle DBA

Answer 1

Is there any way to know if the PERFSTAT.STATS$SQLTEXT table has records that could be purged, yes, just transform Delete to Select
SELECT /*+ index_ffs(st)*/ count(*)
FROM perfstat.stats$sqltext st
WHERE (hash_value, text_subset) NOT IN (
SELECT /*+ hash_aj full(ss) no_expand*/ hash_value, text_subset
FROM perfstat.stats$sql_summary ss
WHERE snap_id NOT IN (SELECT DISTINCT snap_id FROM perfstat.stats$snapshot)
and an easier way, that don't use as much undo, to purge it?yes. do it smaller chunks
BEGIN
LOOP
DELETE /*+ index_ffs(st)*/
FROM perfstat.stats$sqltext st
WHERE (hash_value, text_subset) NOT IN (
SELECT /*+ hash_aj full(ss) no_expand*/ hash_value, text_subset
FROM perfstat.stats$sql_summary ss
WHERE snap_id NOT IN (SELECT DISTINCT snap_id FROM perfstat.stats$snapshot)
) AND ROWNUM<=10000;
EXIT WHEN SQL%ROWCOUNT = 0;
COMMIT;
END LOOP;
COMMIT;
END;
/