What this category of data looks like
Survey and design declaration materials and file review data primarily comes from project submission survey reports, design drawing descriptions, submission application forms, qualification certification documents, site survey records, and similar materials. Data updates proceed alongside project submission progress. The document lengths of single submission materials vary widely. Short submission forms are only a few hundred characters, while long survey reports can reach tens of thousands of characters. Documents include fixed fields such as project number, submission date, drawing version number, survey point coordinates, compliance clause comparison items. Units cover standardized formats such as millimeters, square meters, and date formats.
Constraints imposed on vector models and indexing by these characteristics
The variation in data length requires index chunking strategies to accommodate both long and short texts. This avoids over-splitting long texts and losing compliance clause associations, or splitting short texts into too many invalid chunks. Structured fields such as project number and coordinates require separate index association. Relying solely on full-text vector matching will prevent precise localization of different submission versions for the same project. The incremental update nature of data alongside project progress requires indexes to support incremental synchronization. This avoids performance overhead from full index rebuilding.
How to configure settings
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Value Range | Rationale |
|---|---|---|
| Chunk Length | 800–1200 characters | Accommodates mixed text lengths of survey reports and submission forms, avoids single chunks that are too long to impact encoding accuracy, or too fragmented to increase indexing overhead |
| Overlap Length | 100–200 characters | Retains cross-chunk compliance clause and point association information, prevents loss of context required for review after splitting |
| Similarity Threshold | 0.75–0.85, calibrated via actual testing | Matches similarity of survey point descriptions and compliance clause text, adapts to the precision requirements of review scenarios |
| Single Recall Upper Limit | Top 10 entries | Controls the context scale during review, avoids exceeding the carrying limit of large models |
maxToken | 8000 | Adapts to the context window of mainstream large models, carries review-related text from multiple recalled chunks |
defaultToken | 1500 | Controls the encoding length of a single vector, balances encoding accuracy and vector storage costs |
Three common misconfigurations
- Duplicate file entries appear after index merging. This occurs because deduplication rules are not set for the project number field specific to survey and design, and deduplication is only performed on full text, leading to misjudgment of submission materials from different versions of the same project as duplicates.
- A 401 error is returned when calling the vector model. This occurs because the access key for the vector model is not correctly bound in the FastGPT configuration, or the custom channel does not adapt to the authorization verification logic of the vector model.
- The index order after custom document splitting does not match the original document order. This occurs because the original position markers of chunks are not retained, and some chunks are deleted via deduplication based solely on text content, disrupting the original review order.
How to confirm proper configuration
- Upload a complete survey and design submission package, check whether the number of chunks in the index list matches the number of chunks after custom splitting.
- Submit a compliance review query, verify that the recalled entries include associated content for exclusive fields such as project number and drawing version number.
- Test calling the vector model, confirm that the returned response status code is 200 and there are no authorization-related errors.
- Upload two submission forms with highly similar content, check whether the index retains or merges entries according to the preset rules.
The values provided here are common starting points, and should be evaluated against the reader's own samples.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-28.