# HIMPORT

```json metadata
{
  "title": "HIMPORT",
  "description": "A container for session-based hash import commands using fieldsets.",
  "categories": ["docs","develop","stack","oss","rs","rc","oss","kubernetes","clients"],
  "syntax_fmt": "HIMPORT",
  "complexity": "Depends on subcommand.",
  "group": "hash",
  "acl_categories": ["@hash","@slow"],
  "since": "8.10.0",
  "arity": -2,
  "tableOfContents": {"sections":[{"id":"details","title":"Details"}]}

,
  "codeExamples": []
}
````HIMPORT` is a container command for session-based bulk hash import. Its subcommands let a client import many hashes that share the same field names efficiently by declaring those field names once and then sending only the values for each key.

The subcommands are:

- [`HIMPORT PREPARE`](https://redis.io/docs/latest/commands/himport-prepare) — define a session-local fieldset that names an ordered list of field names.
- [`HIMPORT SET`](https://redis.io/docs/latest/commands/himport-set) — create a hash from a prepared fieldset and a list of values.
- [`HIMPORT DISCARD`](https://redis.io/docs/latest/commands/himport-discard) — remove a single fieldset by name.
- [`HIMPORT DISCARDALL`](https://redis.io/docs/latest/commands/himport-discardall) — remove every fieldset held by the connection.

## Details

A *fieldset* is a named, ordered list of field names that is scoped to the client connection: it is not visible to other clients and is discarded when the connection closes or the client issues the [`RESET`](https://redis.io/docs/latest/commands/reset) command. A connection can prepare several fieldsets, each under its own name, and refer to them by name in later commands.

The typical workflow is to declare a fieldset once with [`HIMPORT PREPARE`](https://redis.io/docs/latest/commands/himport-prepare), then create many keys from it with [`HIMPORT SET`](https://redis.io/docs/latest/commands/himport-set), sending only the values each time:

```
HIMPORT PREPARE u name email age
HIMPORT SET user:1 u alice a@example.com 30
HIMPORT SET user:2 u bob b@example.com 25
```

Because every key created this way shares one fixed set of field names, `HIMPORT` reduces the network traffic and per-command work compared with running [`HSET`](https://redis.io/docs/latest/commands/hset) once per key. Redis also uses the shared field names as a hint to store the keys as [compact hashes](https://redis.io/docs/latest/develop/data-types/hashes#compact-hashes), an internal encoding that keeps a single copy of the field names and reduces memory when many keys share the same layout. This encoding does not change the behavior or replies of any existing hash command.