tag::param-charset[]
`charset`::
(Optional, string) The text's character set. It must be a character set that is
supported by the JVM that {es} uses. For example, `UTF-8`, `UTF-16LE`,
`windows-1252`, or `EUC-JP`. If this parameter is not specified, the structure
finder chooses an appropriate character set.
end::param-charset[]

tag::param-column-names[]
`column_names`::
(Optional, string) If you have set `format` to `delimited`, you can specify the
column names in a comma-separated list. If this parameter is not specified, the
structure finder uses the column names from the header row of the text. If the
text does not have a header row, columns are named "column1", "column2",
"column3", etc.
end::param-column-names[]

tag::param-delimiter[]
`delimiter`::
(Optional, string) If you have set `format` to `delimited`, you can specify the
character used to delimit the values in each row. Only a single character is
supported; the delimiter cannot have multiple characters. By default, the API
considers the following possibilities: comma, tab, semi-colon, and pipe (`|`).
In this default scenario, all rows must have the same number of fields for the
delimited format to be detected. If you specify a delimiter, up to 10% of the
rows can have a different number of columns than the first row.
end::param-delimiter[]

tag::param-explain[]
`explain`::
(Optional, Boolean) If `true`, the response includes a
field named `explanation`, which is an array of strings that indicate how the
structure finder produced its result. The default value is `false`.
end::param-explain[]

tag::param-format[]
`format`::
(Optional, string) The high level structure of the text. Valid values are
`ndjson`, `xml`, `delimited`, and `semi_structured_text`. By default, the API
chooses the format. In this default scenario, all rows must have the same number
of fields for a delimited format to be detected. If the `format` is set to
`delimited` and the `delimiter` is not set, however, the API tolerates up to 5%
of rows that have a different number of columns than the first row.
end::param-format[]

tag::param-grok-pattern[]
`grok_pattern`::
(Optional, string) If you have set `format` to `semi_structured_text`, you can
specify a Grok pattern that is used to extract fields from every message in the
text. The name of the timestamp field in the Grok pattern must match what is
specified in the `timestamp_field` parameter. If that parameter is not
specified, the name of the timestamp field in the Grok pattern must match
"timestamp". If `grok_pattern` is not specified, the structure finder creates a
Grok pattern.
end::param-grok-pattern[]

tag::param-ecs-compatibility[]
`ecs_compatibility`::
(Optional, string) The mode of compatibility with ECS compliant Grok patterns.
Use this parameter to specify whether to use ECS Grok patterns instead of
legacy ones when the structure finder creates a Grok pattern. Valid values
are `disabled` and `v1`. The default value is `disabled`. This setting primarily
has an impact when a whole message Grok pattern such as `%{CATALINALOG}`
matches the input. If the structure finder identifies a common structure but
has no idea of meaning then generic field names such as `path`, `ipaddress`,
`field1` and `field2` are used in the `grok_pattern` output, with the intention
that a user who knows the meanings rename these fields before using it.
end::param-ecs-compatibility[]

tag::param-has-header-row[]
`has_header_row`::
(Optional, Boolean) If you have set `format` to `delimited`, you can use this
parameter to indicate whether the column names are in the first row of the text.
If this parameter is not specified, the structure finder guesses based on the
similarity of the first row of the text to other rows.
end::param-has-header-row[]

tag::param-line-merge-size-limit[]
`line_merge_size_limit`::
(Optional, unsigned integer) The maximum number of characters in a message when
lines are merged to form messages while analyzing semi-structured text. The
default is `10000`. If you have extremely long messages you may need to increase
this, but be aware that this may lead to very long processing times if the way
to group lines into messages is misdetected.
end::param-line-merge-size-limit[]

tag::param-lines-to-sample[]
`lines_to_sample`::
(Optional, unsigned integer) The number of lines to include in the structural
analysis, starting from the beginning of the text. The minimum is 2; the default
is `1000`. If the value of this parameter is greater than the number of lines in
the text, the analysis proceeds (as long as there are at least two lines in the
text) for all of the lines.
+
--
NOTE: The number of lines and the variation of the lines affects the speed of
the analysis. For example, if you upload text where the first 1000 lines
are all variations on the same message, the analysis will find more commonality
than would be seen with a bigger sample. If possible, however, it is more
efficient to upload sample text with more variety in the first 1000 lines than
to request analysis of 100000 lines to achieve some variety.

--
end::param-lines-to-sample[]

tag::param-quote[]
`quote`::
(Optional, string) If you have set `format` to `delimited`, you can specify the
character used to quote the values in each row if they contain newlines or the
delimiter character. Only a single character is supported. If this parameter is
not specified, the default value is a double quote (`"`). If your delimited text
format does not use quoting, a workaround is to set this argument to a character
that does not appear anywhere in the sample.
end::param-quote[]

tag::param-should-trim-fields[]
`should_trim_fields`::
(Optional, Boolean) If you have set `format` to `delimited`, you can specify
whether values between delimiters should have whitespace trimmed from them. If
this parameter is not specified and the delimiter is pipe (`|`), the default
value is `true`. Otherwise, the default value is `false`.
end::param-should-trim-fields[]

tag::param-timeout[]
`timeout`::
(Optional, <<time-units,time units>>) Sets the maximum amount of time that the
structure analysis may take. If the analysis is still running when the timeout
expires then it will be stopped. The default value is 25 seconds.
end::param-timeout[]

tag::param-timestamp-field[]
`timestamp_field`::
(Optional, string) The name of the field that contains the primary timestamp of
each record in the text. In particular, if the text were ingested into an index,
this is the field that would be used to populate the `@timestamp` field.
+
--
If the `format` is `semi_structured_text`, this field must match the name of the
appropriate extraction in the `grok_pattern`. Therefore, for semi-structured
text, it is best not to specify this parameter unless `grok_pattern` is
also specified.

For structured text, if you specify this parameter, the field must exist
within the text.

If this parameter is not specified, the structure finder makes a decision about
which field (if any) is the primary timestamp field. For structured text,
it is not compulsory to have a timestamp in the text.
--
end::param-timestamp-field[]

tag::param-timestamp-format[]
`timestamp_format`::
(Optional, string) The Java time format of the timestamp field in the text.
+
--
Only a subset of Java time format letter groups are supported:

* `a`
* `d`
* `dd`
* `EEE`
* `EEEE`
* `H`
* `HH`
* `h`
* `M`
* `MM`
* `MMM`
* `MMMM`
* `mm`
* `ss`
* `XX`
* `XXX`
* `yy`
* `yyyy`
* `zzz`

Additionally `S` letter groups (fractional seconds) of length one to nine are
supported providing they occur after `ss` and separated from the `ss` by a `.`,
`,` or `:`. Spacing and punctuation is also permitted with the exception of `?`,
newline and carriage return, together with literal text enclosed in single
quotes. For example, `MM/dd HH.mm.ss,SSSSSS 'in' yyyy` is a valid override
format.

One valuable use case for this parameter is when the format is semi-structured
text, there are multiple timestamp formats in the text, and you know which
format corresponds to the primary timestamp, but you do not want to specify the
full `grok_pattern`. Another is when the timestamp format is one that the
structure finder does not consider by default.

If this parameter is not specified, the structure finder chooses the best
format from a built-in set.

If the special value `null` is specified the structure finder will not look
for a primary timestamp in the text. When the format is semi-structured text
this will result in the structure finder treating the text as single-line
messages.

The following table provides the appropriate `timeformat` values for some example timestamps:

|===
| Timeformat                 | Presentation

| yyyy-MM-dd HH:mm:ssZ       | 2019-04-20 13:15:22+0000
| EEE, d MMM yyyy HH:mm:ss Z | Sat, 20 Apr 2019 13:15:22 +0000
| dd.MM.yy HH:mm:ss.SSS      | 20.04.19 13:15:22.285
|===

Refer to
https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html[the Java date/time format documentation]
for more information about date and time format syntax.

--
end::param-timestamp-format[]