What the data for this category looks like
The data for coking coal due diligence reports comes from coal mine production ledgers, port quality inspection reports, futures delivery warehouse receipts, and monthly industry association briefings. Production ledgers update daily, recording the mining site and transportation details for each coking coal batch. Quality inspection reports are issued with each shipment, including fixed quality inspection indicators. Warehouse receipts and industry briefings update weekly or monthly. Supported document formats include text PDFs, Excel ledgers, and Word analysis reports. Core fields include batch number, ash content, sulfur content, volatile matter, caking index, and colloidal layer thickness. Common units are percentage, grams per mole, and millimeters.
What constraints do these characteristics impose on document parsing and chunking?
The structured nature of coking coal documents and inconsistent multi-source formats create multiple parsing and chunking constraints. Document formats vary across sources, requiring adaptation to paragraph breaks in text PDFs, row breaks in Excel files, and table structures in Word documents. Core indicators for a single batch are arranged consecutively. Chunks that are too long will introduce irrelevant content, while chunks that are too short will break the association between related indicators. Parsing large files such as monthly full port warehouse receipts requires processing massive row data. Default configurations may cause timeout errors or merged segments. Some documents use inconsistent unit markings, so the corresponding relationship between fields and units must be preserved during parsing to avoid information loss during subsequent retrieval.
Configuration Settings
| Configuration Item | Recommended Value | Rationale |
|---|---|---|
max_chunk_size | 800–1200 characters | The core indicator fields of coking coal due diligence reports are mostly single values plus descriptions. This length can cover the complete description of quality inspection data for a single batch |
chunk_overlap | 50–100 characters | Prevents consecutive indicators such as caking index and colloidal layer thickness from being split across two segments |
custom_delimiter | \n, batch number, mine site name | Matches row breaks in Excel ledgers and batch identifiers in coking coal documents, avoiding cross-row merging |
UPLOAD_FILE_MAX_SIZE | 2000 MB | Adapts to the upload requirements of large files such as monthly warehouse receipt documents for single batches |
PARSE_FILE_TIMEOUT_SECONDS | 1200 seconds | Large file parsing requires a longer duration to avoid mid-parsing timeout interruptions |
similarity_threshold | 0.75 | Meets the accuracy requirements for matching coking coal quality inspection indicators, filtering low-relevance non-indicator content |
The parameter values provided on this page are conventional recommendations used as a starting point for configuration. Actual values are affected by material form, data volume, and business rules. Specific issues require targeted analysis, and it is recommended to test on your own samples before finalizing settings.
Three Common Configuration Errors
- Phenomenon: A Word document over 10 MB times out during parsing, and the backend log returns
504 Gateway Timeout. Cause: ThePARSE_FILE_TIMEOUT_SECONDSparameter was not adjusted, and the default timeout duration is insufficient to complete full parsing of large files. - Phenomenon: Multiple batches of data imported from an Excel file are merged into a single segment and cannot be split by individual batch. Cause:
custom_delimiterwas not configured, and the default generic delimiter was used, which does not match the batch identifiers and row break rules of coking coal documents. - Phenomenon: Coking coal quality inspection content that exactly matches knowledge base chunks cannot be retrieved, but normal retrieval works after creating a knowledge base with the same configuration. Cause: The
chunk_overlapparameter was not set correctly during initial import, causing the target segment to be truncated and resulting in minor differences from the original content.
How to Verify Correct Configuration
- Upload a coking coal quality inspection PDF under 10 MB, view the parsed segment list, and confirm that each segment contains complete quality inspection indicators for a single batch.
- Import an Excel ledger containing multiple batches, check that each segment corresponds to one row of data with no cross-row merging.
- Upload a large file and check the parsing progress, confirm that no timeout prompt appears within the preset time.
- Enter known coking coal quality inspection indicator text, verify that the corresponding segments can be retrieved from the knowledge base.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-14.