What the Data for This Category Looks Like
Data for this category comes from the real estate registration information system, cadastral survey database, housing transaction online signing system, tax system, and electronic certificate library. The update frequency is daily. Commonly processed documents include registration applications, ownership certificates, surveying and mapping results, tax payment vouchers, real estate ownership certificates, and real estate registration books. Each single document includes structured fields such as parcel number, right holder information, surveying and mapping area, and ownership restriction status, plus unstructured content like supporting scanned documents.
Constraints These Characteristics Impose on the Knowledge Base Retrieval and Recall Link
Multi-source heterogeneous data sources require the retrieval link to support unified field mapping and associated recall of cross-system data. Daily update frequency requires indexes to support incremental synchronization, avoiding performance loss caused by full reconstruction. Documents contain both structured ownership fields and unstructured scanned materials, so a hybrid mode that balances semantic retrieval and exact field matching is needed. The accuracy of ownership information directly affects registration results, so retrieved results must have traceable source identifiers to enable verification of original data during the check phase.
Official Supported Configuration Items
Under FastGPT v4.17.0, the following configuration items are officially supported for retrieval and recall tasks:
| Configuration Item | Recommended Value | Rationale |
|---|---|---|
similarity | 0.72–0.88 | Real estate registration has high requirements for ownership information accuracy. Low-similarity irrelevant documents must be filtered, and this range balances recall rate and accuracy. |
limit | Top 8–12 entries | Real estate registration documents have many associated items. Sufficient ownership, surveying and mapping, and tax data must be covered, and this range meets verification needs. |
searchMode | hybrid | Documents contain both structured fields and unstructured scanned materials. Hybrid mode balances exact field matching and semantic recall performance. |
usingReRank | Enabled | Multi-source data may have redundancy. Reranking improves the ranking priority of highly relevant results and reduces verification costs. |
datasetSearchUsingExtensionQuery | Enabled | Registration documents use standardized wording. Extended queries cover retrieval needs for synonymous expressions and improve recall coverage. |
collectionIds | Bind 2–4 dedicated datasets per business domain | Multi-system data must isolate retrieval scopes by business modules such as cadastral survey, registration application, and tax vouchers to avoid cross-domain interference. |
Three Common Misconfigurations
- Phenomenon: Knowledge base search returns an error prompting
invalid configuration parameter name "hnsw.iter". Cause: A parameter name outside the FastGPT official list was used in the retrieval configuration, and specified configuration items were not employed. - Phenomenon: After adding a language model and index model, no corresponding options appear in the text understanding model dropdown menu when creating a knowledge base. Cause: The model was not associated with the currently used dataset collection, or model loading initialization has not completed.
- Phenomenon: Unauthorized users can access unauthorized real estate registration knowledge base content. Cause: FastGPT's permission isolation function was not enabled, and the access scope of the knowledge base was not divided by business roles.
How to Verify Proper Configuration
- Run a test retrieval, enter the core fields of a registration application, and confirm that the sources of returned results cover data from corresponding business systems.
- Review the retrieval configuration parameter list, and confirm that only officially supported FastGPT configuration items are used, with no extra unspecified parameters.
- Assign limited knowledge base access permissions to a test role, and verify that the role cannot access unauthorized dataset content.
- Trigger an incremental synchronization task, and confirm that index update time aligns with business processing rhythms, with no full reconstruction triggered.
The values provided are common starting points and should be measured 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.