Hi,
We have this table with BLOBs, which has high "enq:HW- contention" from
time to time.
We already have event "44951 TRACE NAME CONTEXT FOREVER, LEVEL 1024" set.
The only option I can think of is to move this BLOB from BASICFILE to
SECUREFILE.
There has been discussion of doing this by using dbms_redefinition here, it
seems to be a great tool that allows changing BLOB online.
This is a very important production database, will there be significant
performance impact using this tool? If so, we may just schedule a
maintenance time.
How long should we expect to redefine 300GB BLOBs? A few hours or a few
days? Can it end up hanging?
Can I take the opportunity to move the BLOB to another tablespace during
this redefinition process?
Thank you for your information.
Chen
