What This Category’s Data Looks Like
The data for this category primarily comes from the national unified construction project environmental impact assessment declaration and approval system, ecological environment zoning control results, pollution discharge permit platform, and monitoring data. Commonly processed documents include environmental impact assessment reports or report forms, approval applications, public participation explanations, technical evaluation opinions, and environmental impact assessment approvals. Each document contains fixed fields such as project number, project category, environmental impact assessment level, pollution prevention measures, and public participation opinions. Data updates follow no fixed cycle, and are added or modified irregularly alongside project declaration and approval progress.
Constraints on Vector Models and Indexing Imposed by These Characteristics
Data sources for this category are scattered and have diverse formats. Document lengths vary significantly: long documents can reach tens of thousands of characters, while short approval documents only contain hundreds of characters. This requires flexible vector chunking. Data updates follow no fixed cycle, so incremental indexing must be supported to avoid redundant overhead from full reconstruction. Core fields such as project category, environmental impact assessment level, and pollution prevention measures directly relate to approval outcomes. Core semantics must be prioritized during indexing, and index recall accuracy must be guaranteed to avoid approval errors caused by matching deviations.
How to Configure the System
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
| Chunk Length | 800–1200 characters | Adapts to the semantic integrity of documents such as environmental impact assessment reports and approval applications, and avoids truncation across core business chunks |
| Overlap Length | 100–200 characters | Reduces semantic gaps between chunks, and ensures that core fields such as project number are fully covered in adjacent chunks |
defaultToken | 2000 token | Matches the maximum load of a single batch of indexing, and adapts to the average length of a single environmental impact assessment document |
maxToken | 4000 token | Limits the maximum vector generation length of a single index data entry, to avoid exceeding the model input limit |
| Similarity Threshold | 0.75–0.85 | Filters low-match retrieval results, and ensures the recall accuracy of approval-related content |
| Single Search Limit | Top 10 entries | Controls the number of results returned by retrieval, to avoid redundant information interfering with approval staff judgment |
Three Common Misconfigurations
- Issue: An error occurs when importing CSV-format environmental impact assessment documents after upgrading the platform version. The error prompts that the field format does not match. Root cause: The new version adjusts the verification rules for CSV column names, and does not retain the field alias configuration compatible with older versions.
- Issue: The knowledge base indexing task gets stuck. Unfinished tasks show a "processing" status with no progress updates. Root cause: Breakpoint resume logic for incremental indexing is not configured. The task is interrupted due to timeout of a single long document during full indexing.
- Issue: Retrieval results include historical environmental impact assessment approvals that are unrelated to the current project. Root cause: The similarity threshold is set too low, which recalls documents with similar semantics but mismatched project categories.
How to Verify Correct Configuration
- Upload a single environmental impact assessment approval document, and check whether the number of index-generated chunks matches the expected chunk length setting.
- Trigger an incremental indexing task, and verify that only newly added environmental impact assessment documents are included in the index, with no full reconstruction triggered.
- Enter a test query such as "the environmental impact assessment level of a project", and check whether the core fields of the returned results match the parameters of the current project.
- View the indexing logs to confirm that the
defaultTokenandmaxTokenconfigurations do not exceed the system default limits.
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.