How to remove unwanted parameters from init.ora using a shell script

1. Create a "removal list" containing your unwanted parameters. For example, put the following into a text file called removal_list.txt, and save it in $ORACLE_HOME/dbs:

_b_tree_bitmap_plans
_fast_full_scan_enabled
_grant_secure_role
_like_with_bind_as_equality
_projection_pushdown

2. create a Shell script to loop through the lines in remval_list.txt, called remove_params.sh:

for a in $(cat removal_list.txt ); do
 echo now testing $a
 sleep 1
 curr_param=`grep -w $a init${ORACLE_SID}.ora | awk -F '[=]' '{ print $1 }'`
 if [ $curr_param ]; then
  echo removing $curr_param
  sed -i "/${curr_param}/d" init${ORACLE_SID}.ora
  sleep 1
 else
  echo $a not found in parameter file. Skipping...
  sleep 1
 fi;
done
exit 0

It is important to use the -w flag with grep, as many Oracle initialization parameters can be named similarly and the script will then save multiple values in the curr_param variable

3. Make Your script executable:

chmod 755 remove_params.sh

4. execute the script:

./remove_params.sh

Expected output:

now testing _b_tree_bitmap_plans
removing _b_tree_bitmap_plans
now testing _fast_full_scan_enabled
removing _fast_full_scan_enabled
now testing _grant_secure_role
_grant_secure_role not found in parameter file. Skipping...
now testing _like_with_bind_as_equality
removing _like_with_bind_as_equality
now testing _projection_pushdown
_projection_pushdown not found in parameter file. Skipping...