The scan operator produces a result array that is equivalent to a stored array. That is, scan reads a stored array.

Synopsis

scan(stored_array);

Inputs

stored_array: An array that was previously created and stored in SciDB.

Summary

The scan operator reads a stored array from disk. The scan operator's output is an array with the same content as stored_array. The scan operator is most useful for displaying a stored array on stdout from the AFL language.

Example

To create, build, scan, and store an array, do the following:

Create a 3×3 array called m3x3_A:

AFL% CREATE ARRAY m3x3_A <val_A:double>[i=0:2; j=0:2];

The output is:

Query was executed successfully

Put values of 0–8 into the m3x3_A array:

 AFL% store(build(m3x3_A,i*3+j),m3x3_A);

The output is:

{i,j} val_A
{0,0} 0
{0,1} 1
{0,2} 2
{1,0} 3
{1,1} 4
{1,2} 5
{2,0} 6
{2,1} 7
{2,2} 8

Create the m3x3_B array

AFL% CREATE ARRAY m3x3_B <val_B:double>[i=0:2; j=0:2];

The output is:

Query was executed successfully

Use scan to display m3x3_A array:

AFL% scan(m3x3_A);

The output is:

{i,j} val_A
{0,0} 0
{0,1} 1
{0,2} 2
{1,0} 3
{1,1} 4
{1,2} 5
{2,0} 6
{2,1} 7
{2,2} 8

Use scan to display m3x3_B array:
```
AFL% scan(m3x3_B);
```
The output is:
```
{i,j} val_B
```

Store the scan output of array m3x3_A into the m3x3_B array:

AFL% store(scan(m3x3_A), m3x3_B);

The output is:

{i,j} val_B
{0,0} 0
{0,1} 1
{0,2} 2
{1,0} 3
{1,1} 4
{1,2} 5
{2,0} 6
{2,1} 7
{2,2} 8

Scan m3x3_B to ensure it has the expected data

AFL% scan(m3x3_B);

The output is:

{i,j} val_B
{0,0} 0
{0,1} 1
{0,2} 2
{1,0} 3
{1,1} 4
{1,2} 5
{2,0} 6
{2,1} 7
{2,2} 8

Remove the m3x3_A array:

AFL% remove(m3x3_A);

The output is:

Query was executed successfully

Remove the m3x3_B array:

AFL% remove(m3x3_B);

The output is:

Query was executed successfully

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