The versions operator shows array versions.

Synopsis

versions(named_array);

Summary

The versions operator lists all versions of an array in the SciDB database.  Each version has a version ID and date/time of creation.

Example

To create an array with two versions, do the following:

1. Create an array containing all 1's:

   AFL% create array A <val:double>[i=1:2];
   AFL% store(build(A, 1), A);

   
   The output is:

   {i} val
   {1} 1
   {2} 1

2. Change the values to 2:
   

   AFL% store(build(A, 2), A)

   
   The output is:
   

   {i} val
   {1} 2
   {2} 2

    

3. Use the versions operator to list the versions of array A:
   

   AFL% versions(A); 

   
   The output is:
   

   {VersionNo} version_id,timestamp
   {1} 1,'2016-02-26 18:19:39'
   {2} 2,'2016-02-26 18:21:28'  

    

4. Use the scan operator and the @ array version specifier to access a version other than the last:
   

   AFL% scan(A@1);  

   
   The output is:

   {i} val
   {1} 1
   {2} 1