In an AWR report I see the following (most liekly recursive) query which happens very often and is parsed each time:

select obj#, intcol#, ts#, file#, block#, property from lob$ where lobj#=:1

The AWR entry for SQL ordered by parse calls:

Parse Calls Executions  % Total Parses SQL Id        SQL Module SQL Text
411,384     411,414     39.62          6y55dxn24t86q select obj#, intcol#, ts#, fil...

Any idea which component is generating that and why it is not a prepared statement? (since our app sets "module" everywhere we know its not directly executed from us).

We do use LOBs heavily, so this can be related to reorganisation or maybe data guard?

  • Maybe it’s from a Jdbc driver meta data operation? (The execution count does not suggest typical scheduled system jobs)
    – eckes
    Jul 20, 2019 at 2:45

1 Answer 1


SQL_ID - 6y55dxn24t86q is related to space management coordinator process (SMCO background process). If you are seeing too many wnnn slave process, disable it by

alter system set "_enable_spacebg"=false;

  • Thanks! Du you have an idea why it is parsing each execution, is that because new processes are started or just a missing logic for keeping the handles open in the component? (I haven’t seen it since on other systems, maybe update fixed it, so I am just curious if I can PinPoint a traffic pattern or missconfiguration to avoid for some customers)
    – eckes
    Jun 25, 2021 at 21:25

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