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

# Limits

> For the complete documentation index optimized for AI agents, see [llms.txt](/llms.txt).

Current constraints and practical limits. These reflect the current implementation, not
fundamental architectural boundaries.

## Data Model

| Limit                  | Value                                                                                                                                                                                                                                                          |
| ---------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Node and edge ID range | 64-bit unsigned integer (max 2^63)                                                                                                                                                                                                                             |
| Property value types   | boolean, integer, float, string, bytes, typed primitive arrays, generic arrays, and objects                                                                                                                                                                    |
| Nested structures      | Stored object/array values are supported. Dotted-path lookup such as `metadata.externalID` works in scan-time filters, expressions, projections, `values`, filtered `valueMap`, and fallback ordering. Arrays are opaque; there is no array-index path syntax. |
| Reserved property keys | `$label` (used for label-based filtering and label-scoped secondary, vector, and text indexes)                                                                                                                                                                 |

## Vector Indexes

| Limit                    | Value                                                                                                                                    |
| ------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------- |
| Scope                    | Node and edge properties                                                                                                                 |
| Supported property types | Numeric array properties (`float32[]`, `float64[]`, `int64[]`) normalized to `float32` for indexing                                      |
| Tenant partitioning      | Optional by configured tenant property name. Tenant-scoped searches require a tenant value. Unknown tenant partitions return no results. |
| Dimension matching       | Vectors must exactly match the configured index dimension                                                                                |
| Distance metrics         | cosine, euclidean, manhattan                                                                                                             |
| Search type              | Approximate nearest neighbor (ANN)                                                                                                       |

## Text Indexes

| Limit                    | Value                                                                                                                                                         |
| ------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Scope                    | Node and edge properties                                                                                                                                      |
| Supported property types | Top-level `String` and `StringArray` properties. Nested object fields are not flattened for BM25.                                                             |
| Unsupported values       | `null` and non-string values are rejected                                                                                                                     |
| Analyzer config          | Preset analyzers: `standard`, `standard_stem_en`, `whitespace_lowercase`                                                                                      |
| Term positions           | Optional                                                                                                                                                      |
| Tenant partitioning      | Optional. Tenant-partitioned text indexes currently require the partition property name to be `tenant_id`, and tenant-scoped searches require a tenant value. |

## Secondary Indexes

| Limit            | Value                                                                                                      |
| ---------------- | ---------------------------------------------------------------------------------------------------------- |
| Equality indexes | Supported on top-level node and edge properties. Nested dotted paths are scan-only in V1.                  |
| Range indexes    | Supported on top-level numeric and string properties. Nested dotted paths are scan-only in V1.             |
| Encoding         | Range indexes use lexicographic string encoding. Values must be encoded consistently for correct ordering. |

## Queries

| Limit             | Value                                |
| ----------------- | ------------------------------------ |
| Query model       | Dynamic queries                      |
| Query language    | SDK DSLs or dynamic JSON AST         |
| Transaction scope | One transaction per query invocation |