Table Column Type Tag Profiler
Profile actual JSON value types in a complete supplied column; no coercion, inferred dates or sampling bias.
Description
Profile actual JSON value types in a complete supplied column; no coercion, inferred dates or sampling bias.
A column's JSON type profile can distinguish null and arrays from generic objects. It describes observations rather than inferring a schema.
When to use this tool
Profile actual JSON value types in a complete supplied column; no coercion, inferred dates or sampling bias.
- Prepare the supplied columnJson fields for this operation.
- Compare the complete example with the representation used by your own input before carrying the result into another step.
How to use the tool and how it works
- Enter columnJson. Use the exact text syntax, units and index conventions explained below.
- Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
- Read result.tags, result.counts. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Parse columnJson as a JSON list. Tag each entry as null, array or its JavaScript scalar/object type and group tag counts by first occurrence.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| columnJson | JSON text, entered as one text field. The decoded structure is illustrated below; it is not a separate file. | Text |
For the JSON text fields, the following decoded structures show the example records before they are serialized into input strings. Keep field names, list nesting and value types as shown.
[
{
"field": "columnJson",
"decoded": [
null,
1,
"1",
true,
1
]
}
]| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.tags | The tags list in the ordering and representation described above. |
| result.counts | The counts list in the ordering and representation described above. |
{
"input": {
"columnJson": "[null,1,\"1\",true,1]"
},
"output": {
"result": {
"tags": [
"null",
"number",
"string",
"boolean",
"number"
],
"counts": [
{
"tag": "null",
"count": 1
},
{
"tag": "number",
"count": 2
},
{
"tag": "string",
"count": 1
},
{
"tag": "boolean",
"count": 1
}
]
}
}
}Limitations and assumptions
- No coercion, nested type validation or missing-cell policy is inferred. Mixed types are reported rather than rejected.
- Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
- Lists are limited to 128 entries. JSON text must meet bounded size and depth checks, and numeric outputs beyond the safe finite magnitude are rejected. Exact large integers use decimal strings.
- Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.
Alternative or Complementary methods
Choose the exact text grammar before combining serializers and parsers. UTF-16 record lengths, raw separators and custom backslash escapes differ from byte framing, CSV, Markdown and spreadsheet semantics.
References
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