I am in Oracle EE 19.21 in AWS RDS. I am testing approaches to improve materialized view refresh using DB link. I found out parallelism does not work with distributed MVIEW per Doc ID 577870.1 so wanted to see if changing SDU size would help.
I found no changing SDU size from default 8192 to 65535 or making it 2MB.
I change both server sqlnet setting as well as database link definition.
Moreover, it seem SDU size is already 3.5MB when default_sdu_size is 8192.
I calculated this based on “bytes received via SQL*Net from dblink”which was around 580 MB and “SQL*Net roundtrips to/from dblink” is 162.
Even if I change SDU , I get same “SQL*Net roundtrips” and same elapsed time. Am I missing anything?
We are not using “Oracle Advanced Network Compression Service”
create materialized view test_sdu as select * from mils.license@test_without_sdu ;
Materialized view created.
Elapsed: 00:00:32.33
SELECT name, VALUE
FROM v$statname sn, v$mystat ms
WHERE ms.VALUE != 0 AND sn.statistic# = ms.statistic#
and name like '%SQL*Net %'order by value desc;
bytes received via SQL*Net from dblink 608765247 #580.5 MB
bytes sent via SQL*Net to dblink 25802
bytes received via SQL*Net from client 5151
bytes sent via SQL*Net to client 4767
SQL*Net roundtrips to/from dblink 162 # this would be 3.5MB / sdu change did not imapct
SQL*Net roundtrips to/from client 14
Thanks in advance.