Heavy enq TX - allocate ITL entry (only 4500 insetrs took an average of 225 sec)

Hi Gurus,

 

Could you please help me understand this issue.

i have a table with 10 million entries only with an average row length of 36. the primary key is an incremental sequence number. the only indexed column is Primary key(oracle default indexed).

there are only 5 columns and three out of them are number, two varchar2.

 

Now suddenly after below changed done on the RAC system we started seeing the issue of

Very heavy ITL event only on the primary key index of this table, (we have another 80+ similar kind of primary keys, now have shown any issue even with 1million+ inserts and deletes) .