# i (local index) processing code

The i processing code indicates that
an index exists for the current attribute. It must be defined in the
attribute-defining item that corresponds to a local B-tree index previously
created with a create-index command.

This processing code is supported only from the VME.

| System Processors | Update |
| --- | --- |
| Code Type | Attribute Defining |
| Dictionary Attributes | Input Conversion |

## Syntax

```
i
```
**Utilizing D3 B-tree indexes consists of a two step process:**

- Create the index. The create-index command establishes a new B-tree index.

- Define the attribute index correlative on the input-conversion attribute (attribute 14) of the dictionary. There may be one (either local or remote) or two (one local and one remote) indexes defined in any given attribute-defining item.

To access data in other files, see i (index,
remote) processing code.

When editing data in the attribute
using the Update processor, the operator can *cruise* forward
and backward through the items in the file.

| CTRL+D | Accesses the previous item based on the index. |
| --- | --- |
| CTRL+F | Accesses the next item. |
A bell signifies the beginning or end of the index. There
can be more than one index created on any given attribute. If more
than one index exists, the desired format must be specified.

## Example(s)

Create an index on attribute
1:

```
create-index filename a1
```
The i processing code must be added
to the input-conversion attribute of the corresponding attribute-defining
item before the index may be used by the Update processor.

Create
an index consisting of attribute 1 concatenated with attribute 2:

```
create-index filename a1:2
```

## See also

- [a (algebraic) processing code](https://d3codex.com/processingcodes/a-algebraic-processing-code/)
- [B-tree](https://d3codex.com/definitions/b-tree/)
- [create-index command](https://d3codex.com/tcl/create-index-command/)
- [Cruising and zooming commands](https://d3codex.com/updateprocessor/cruising-and-zooming-commands/)
- [Cruising and zooming commands](https://d3codex.com/updateprocessor/cruising-and-zooming-commands/)
- [i (remote index) processing code](https://d3codex.com/processingcodes/i-remote-index-processing-code/)
- [Processing codes (Update processor)](https://d3codex.com/updateprocessor/processing-codes-update-processor/)
- [macro attribute](https://d3codex.com/updateprocessor/macro-attribute/)
- [output-conversion](https://d3codex.com/attributedefiningitem/output-conversion/)
- [Processing codes overview](https://d3codex.com/processingcodes/processing-codes-overview/)
- [Processing codes (Update processor)](https://d3codex.com/updateprocessor/processing-codes-update-processor/)
- [ud command](https://d3codex.com/tcl/ud-command/)

---
Source: https://d3codex.com/processingcodes/i-local-index-processing-code/ - part of the D3Codex reference.