Oracle 12.2 shows high parse per execution ratio for unknown lob$ query

Question

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?

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;