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Re: Unique index access path seems very slow

From: Jonathan Lewis <jlewisoracle_at_gmail.com>
Date: Fri, 27 Jan 2023 13:31:40 +0000
Message-ID: <CAGtsp8=LFT8zKedFtGcGGipYnLKO4tCRHH8iuBx4wxi9xtX9Yw_at_mail.gmail.com> 








Just one quick answer, I'll get back to the rest of the posting later today
(I hope).


For the storage of the raw vs. hex, the length() and lengthb() will
implicitly convert to hex before calculating the length.
For internal storage size try:


SQL> select sys_op_opnsize(c1), sys_op_opnsize(c2) from t1_encrypt;
SQL> select vsize(c1), vsize(c2) from t1_encrypt;
SQL> select dump(c1,16), dump(c2,16) from t1_encrypt;





The first two are the newer and older (respectively) calls used in
gather_table_stats() to get internal column lengths
The last is a way to dump the actual bytes store, in this case in base 16,
reportung the column type and length at the start



You'll see the 64 vs. 128 in all three.



Regards


Jonathan Lewis


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Received on Fri Jan 27 2023 - 14:31:40 CET












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