What data for this use case looks like
Documents for railway operations internal office and employee services mainly come from logs returned from job sites, shift schedules from internal office systems, maintenance manuals, employee training materials, and regulatory documents. Update frequency differs across document types: daily shift schedules are updated daily, train operation logs are updated per train operation node, and regulatory documents are updated quarterly or annually through approval workflows. Document structures include plain text operation specifications, multi-line structured tables, PDFs with embedded fonts, and PPTs with embedded charts. Fields include train numbers, operation durations, fault codes, attendance days, and more. Units include kilometers, hours, person-times, and other professional operation and maintenance identifiers.
Constraints for document parsing and chunking
The mixed multi-type structure and specialized terminology of railway documents create multiple constraints for the parsing and chunking process. Multi-line structured tables require the parsing stage to accurately identify merged cells and cross-row content, to avoid truncating table semantics during chunking. Logs updated per operation nodes and large volumes of frequently uploaded files require the parsing stage to support large file sizes and batch task processing. Internal documents using non-standard character encoding require the parsing stage to adapt to special character sets, to avoid encoding errors. Intensive use of professional operation and maintenance terminology requires chunk intervals to retain complete associations between terms and their context, to prevent semantic breaks.
Configuration settings
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
chunkSize | 800–1200 characters | Railway internal documents include multi-line tables and professional operation and maintenance terms. This range preserves complete semantics for a single operation process or single table |
chunkSplitter | Split by paragraph + table | Railway documents mix long-text operation specifications and structured tables. This splitting method prevents table content from being truncated by plain text rules |
customPdfParse | Enabled | Railway PDF documents often contain embedded special fonts or encrypted forms. Enabling custom parsing improves format compatibility |
UPLOAD_FILE_MAX_SIZE | 1000 MB | Railway internal teams upload compressed packages of batch historical operation logs. This upper limit covers standard batch upload requirements |
PARSE_FILE_TIMEOUT_SECONDS | 600 seconds | Large multi-page PDFs or complex Excel tables take longer to parse. This duration prevents task interruption due to timeout |
chunkSettingMode | Manual configuration | Railway documents have large format differences. Manual configuration allows flexible adjustment of chunking parameters to adapt to different file types |
Three common configuration errors
- When uploading PPT or PDF files containing special characters, the interface returns an encoding error prompt. The cause is that the
customPdfParseconfiguration is not enabled, and the system fails to adapt to the non-standard character encoding used in railway documents. - After uploading a multi-line Excel shift schedule, cell content is misaligned and cross-row content is missing in the knowledge base. The cause is that
chunkSplitteris not configured to split by paragraph + table, resulting in structured tables being truncated by plain text rules. - When uploading a compressed package of historical operation logs in batch, the parsing task times out and fails. The cause is that the
PARSE_FILE_TIMEOUT_SECONDSsetting value is lower than the actual parsing time of large multi-page documents, and sufficient processing time is not reserved.
How to verify correct configuration
- Upload an Excel shift schedule containing multi-line tables, and check if the parsed knowledge base chunks retain the complete content of a single table without cell misalignment.
- Enter the system configuration interface, and confirm that the
customPdfParseoption is enabled. - Upload a 500MB PDF operation manual, and check if the parsing task completes within 600 seconds with no error prompts.
- Try uploading a 1100MB compressed package, and confirm that the system prompts that the file exceeds the upload limit.
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.