Summary

The first form of the remove_versions operator removes all versions of an array older than the specified version_id.  The second form keeps the count  most recent versions, removing all earlier versions.  The third form removes all but the most recent version.

Inputs

• named_array - the name of the array from which you are removing versions.
• version_id - removes all versions up to the version_id, but not including the version_id.
• keep: N - remove all but the last N versions

Examples

Using the Operator

To demonstrate remove_versions operator, do the following:

1. From the command shell, use iquery to create an array and store several versions of data into it:

   $ iquery -aq "create array A<val:double>[i=0:4]"
   Query was executed successfully
   $ for x in $(seq 1 5) ;do iquery -naq "store(build(A, 10 + $x), A)" ;done 
   Query was executed successfully 
   Query was executed successfully
   Query was executed successfully
   Query was executed successfully
   Query was executed successfully
   $ 

2. Use list('arrays', true) to see all versions of the array, and inspect the values from some older versions:

   $ iquery -a
   AFL%  list('arrays', true);
   {No} name,uaid,aid,schema,availability,temporary,namespace
   {0} 'A',60,60,'A<val:double> [i=0:4:0:*]',true,false,'public'
   {1} 'A@1',60,61,'A@1<val:double> [i=0:4:0:1000000]',true,false,'public'
   {2} 'A@2',60,62,'A@2<val:double> [i=0:4:0:1000000]',true,false,'public'
   {3} 'A@3',60,63,'A@3<val:double> [i=0:4:0:1000000]',true,false,'public'
   {4} 'A@4',60,64,'A@4<val:double> [i=0:4:0:1000000]',true,false,'public'
   {5} 'A@5',60,65,'A@5<val:double> [i=0:4:0:1000000]',true,false,'public'
   AFL% 
   AFL% scan(A@3);
   {i} val
   {0} 13
   {1} 13
   {2} 13
   {3} 13
   {4} 13
   AFL% scan(A@2);
   {i} val
   {0} 12
   {1} 12
   {2} 12
   {3} 12
   {4} 12

3. Remove all versions earlier than version 3:

   AFL% remove_versions(A, 3);
   Query was executed successfully
   AFL%
   AFL% list('arrays', true);
   {No} name,uaid,aid,schema,availability,temporary,namespace
   {0} 'A',60,60,'A<val:double> [i=0:4:0:*]',true,false,'public'
   {1} 'A@3',60,63,'A@3<val:double> [i=0:4:0:1000000]',true,false,'public'
   {2} 'A@4',60,64,'A@4<val:double> [i=0:4:0:1000000]',true,false,'public'
   {3} 'A@5',60,65,'A@5<val:double> [i=0:4:0:1000000]',true,false,'public'
   {4} 'foo',53,53,'foo<a:int32> [i=0:50000:0:1000]',true,false,'public'

4. Remove all but the last two versions:

   AFL% remove_versions(A, keep: 2);
   Query was executed successfully
   AFL% 
   AFL% list('arrays', true);
   {No} name,uaid,aid,schema,availability,temporary,namespace
   {0} 'A',60,60,'A<val:double> [i=0:4:0:*]',true,false,'public'
   {1} 'A@4',60,64,'A@4<val:double> [i=0:4:0:1000000]',true,false,'public'
   {2} 'A@5',60,65,'A@5<val:double> [i=0:4:0:1000000]',true,false,'public'
   

5. Keep the latest version, removing everything else:

   AFL% remove_versions(A);
   Query was executed successfully
   AFL% 
   AFL% list('arrays', true);
   {No} name,uaid,aid,schema,availability,temporary,namespace
   {0} 'A',60,60,'A<val:double> [i=0:4:0:*]',true,false,'public'
   {1} 'A@5',60,65,'A@5<val:double> [i=0:4:0:1000000]',true,false,'public'

6.  Remove the rest of the versions of the array:

   AFL% remove(A);
   Query was executed successfully
   AFL%