| merge | No | Whether new data should merge/upsert into existing rows rather than append. For sourceType "tables" also changes the generated SQL between MERGE and INSERT. | |
| specName | Yes | Name of the existing data spec to update | |
| computeSize | No | Compute size for analysis/processing. Omit to keep the current setting. | |
| description | No | New description for the spec. Omit to keep the current value. | |
| runAnalysis | No | Whether to run analysis and wait for it after saving the changes (default true). Only applies to the synchronous (no-file-change) path. | |
| workspaceId | No | Workspace to act on. Defaults to your only workspace if you have exactly one. | |
| sourceTables | No | sourceType "tables" specs only: replacement list of source tables the generated query reads from. | |
| targetOption | No | Change where transformed data lands. Omit to keep the current setting. | |
| targetTables | No | sourceType "file" specs: new list of existing workspace tables to load into. Required when setting targetOption to "existing-tables". sourceType "tables" specs: the query's single target table name — pass a one-element array to rename the target (its schema is re-resolved per the spec's targetOption). | |
| formatFileName | No | sourceType "file" specs only. File name of a replacement format spec file, if replacing it. | |
| loadSampleData | No | Whether re-analysis should also trigger the data-load job (default true). Only used when runAnalysis is true. | |
| sampleFileName | No | sourceType "file" specs only. File name of a replacement sample data file, if replacing it. | |
| additionalPrompt | No | Extra natural-language guidance for the AI schema inference/mapping. Replaces the previously stored value when given (omit to keep it as-is), and is reused on every future re-analysis — keep it to instructions that actually change behavior. Don't restate default platform behavior (e.g. that unmapped target columns are null on insert and preserved on merge match) just to document it; a note only true for one case (like new rows) can read as a standing instruction later and confuse updates. | |
| targetSchemaFileName | No | File name of a replacement target schema file. Required when setting targetOption to "target-schema-file". | |