Hi
fellow DBAs,
This
is kind of the follow-up of my last E-mail on wait event.
I have
a query that is taking hours to complete and the plan looks ok. While one of the
tables is huge (267mil rows) it is being accessed using one of its
indexes.
I
recorded some stats from v$session_wait while the query is running to see which
segment is query is hanging up on and the result is the big table with 267mil
rows.
Funny
thing is, according to the user community, this query took only minutes to run
couple of weeks ago.
What
could be the cause of this wait? When index is being used, oracle will go
directly to the data block and retrieve the data, which should be very efficient
correct?
TIA
Dennis
