我们注意到,在Oracle9iR2中,和DBWR相关的统计事件有12个,分别为:
SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production PL/SQL Release 9.2.0.4.0 - Production CORE 9.2.0.3.0 Production TNS for Linux: Version 9.2.0.4.0 - Production NLSRTL Version 9.2.0.4.0 - Production SQL> select name from v$statname where name like '%DBWR%'; NAME ---------------------------------------------------------------- DBWR checkpoint buffers written DBWR transaction table writes DBWR undo block writes DBWR revisited being-written buffer DBWR make free requests DBWR free buffers found DBWR lru scans DBWR summed scan depth DBWR buffers scanned DBWR checkpoints DBWR cross instance writes DBWR fusion writes 12 rows selected. |
在Oracle10gR1中,这类事件上升为15个:
SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.1.0.3.0 - 64bi PL/SQL Release 10.1.0.3.0 - Production CORE 10.1.0.3.0 Production TNS for Solaris: Version 10.1.0.3.0 - Production NLSRTL Version 10.1.0.3.0 - Production SQL> select name from v$statname where name like '%DBWR%'; NAME ---------------------------------------------------------------- DBWR checkpoint buffers written DBWR thread checkpoint buffers written DBWR tablespace checkpoint buffers written DBWR parallel query checkpoint buffers written DBWR object drop buffers written DBWR transaction table writes DBWR undo block writes DBWR revisited being-written buffer DBWR make free requests DBWR free buffers found DBWR lru scans DBWR summed scan depth DBWR buffers scanned DBWR checkpoints DBWR fusion writes 15 rows selected. |