fieldstats

Analyzes dynamic column values to discover field paths and their statistics, returning a table with AttributePath, Type, Cardinality, Frequency, Hint, and HintExhaustive columns.

Analyzes dynamic column values to discover field paths and their statistics, returning a table with AttributePath, Type, Cardinality, Frequency, Hint, and HintExhaustive columns. HintExhaustive is true when the Hint values represent the complete set of distinct values.

Useful for exploring JSON-like data to understand what fields exist across records. Supports analyzing multiple columns in a single call. If no columns are specified, analyzes all input columns (or the _ column if present).

IMPORTANT: This is an expensive operation. Use the with limit=N parameter to limit samples (default 1000), or use | take N before fieldstats.

Use with depth=N to control how deep to descend into nested dynamic structures. When the depth limit is reached, nested objects and arrays are reported as dynamic type instead of recursing into their contents. depth=1 means only top-level fields.

Syntax

fieldstats [columns] [with limit=N depth=M]

Analyze fields in columns (all columns if none specified)

Parameters

Name	Description
columns	Columns to analyze (all columns if omitted) (optional)

`with limit=`

Maximum rows to sample (default 1000)

Value	Description
`N`	Sample at most N rows.

`with depth=`

Nesting depth for dynamic columns

Value	Description
`N`	Recurse at most N levels (N must be > 0). depth=1 means top-level fields only.

Examples

Example 1 — Discover fields in a dynamic column

datatable(log:dynamic)[
  dynamic({"warrior":"Ragnar", "weapon":"axe", "voyages":42}),
  dynamic({"warrior":"Bjorn", "weapon":"sword", "voyages":31}),
  dynamic({"warrior":"Ivar", "weapon":"bow", "voyages":35})
]
| fieldstats log

AttributePath (string)	Type (string)	Cardinality (long)	Frequency (real)	Hint (dynamic)	HintExhaustive (bool)
log.voyages	long	3	1.0	["31","35","42"]	true
log.warrior	string	3	1.0	["Bjorn","Ivar","Ragnar"]	true
log.weapon	string	3	1.0	["axe","bow","sword"]	true

Example 2 — Analyze top-level fields only

datatable(log:dynamic)[
  dynamic({"ship":{"name":"Naglfar", "crew":80}, "destination":"Lindisfarne"}),
  dynamic({"ship":{"name":"Wave Rider", "crew":45}, "destination":"York"})
]
| fieldstats log with depth = 1

AttributePath (string)	Type (string)	Cardinality (long)	Frequency (real)	Hint (dynamic)	HintExhaustive (bool)
log.destination	string	2	1.0	["Lindisfarne","York"]	true
log.ship	dynamic	0	1.0	null	true

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