> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kinetica.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Iteration

<a id="sql-iteration" />

*Kinetica* supports [iteration](/content/concepts/iteration) over each
record within a data set for the purpose of creating a result set with `0` to
`N` result records per record in the original set.

This iteration can be variable, based on some value within each record, or
fixed, based on a given constant value.

The *iteration* is performed by joining against the virtual `ITER` table, as
follows:

```sql title="Iteration Syntax" theme={null}
SELECT *
FROM table, ITER
WHERE ITER.i < <column expression>
```

The `<column expression>` can be replaced by a constant for fixed *iteration*.

For example, to extract all of the individual letters from a column of words,
with one record per letter extracted (using variable iteration):

```sql Iteration Over Column Values Example theme={null}
SELECT id, word, i, SUBSTR(word, i + 1, 1) AS letter
FROM example.dictionary
JOIN ITER ON i < LENGTH(word)
ORDER BY id, i
```

To duplicate the set of words five times (using fixed iteration):

```sql Iteration Over Table Example theme={null}
SELECT i, id, word
FROM example.dictionary, ITER
WHERE i < 5
ORDER BY id, i
```

For more detail, examples, and limitations, see
[Iteration](/content/concepts/iteration).