Daily Archives: 20.01.2021


Long parsing on Oracle 12.2 and the discovery of SQLT Xplore

Today I discovered a fantastic free tool from Oracle: SQLT Xplore!

At a client I had one query that took long time parsing. The tkprof result of the 10046 trace showed it took 5 seconds to parse:

call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse        1      5.17       5.30          0          0          0           0
Execute      1      0.00       0.00          0          0          0           0
Fetch        1      0.00       0.00          0        665          0          26
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        3      5.17       5.30          0        665          0          26

Looking around I’ve noticed that disabling the cost based transformation:

ALTER SESSIONS SET "_optimizer_cost_based_transformation"=off;  

…the query was much faster to parse: only 0,5 seconds.

(more…)