[[esql-limitations]]
== {esql} limitations

++++
<titleabbrev>Limitations</titleabbrev>
++++

[discrete]
[[esql-max-rows]]
=== Result set size limit

By default, an {esql} query returns up to 500 rows. You can increase the number
of rows up to 10,000 using the <<esql-limit>> command.
include::processing-commands/limit.asciidoc[tag=limitation]

[discrete]
[[esql-supported-types]]
=== Field types

[discrete]
==== Supported types

{esql} currently supports the following <<mapping-types,field types>>:

* `alias`
* `boolean`
* `date`
* `double` (`float`, `half_float`, `scaled_float` are represented as `double`)
* `ip`
* `keyword` family including `keyword`, `constant_keyword`, and `wildcard`
* `int` (`short` and `byte` are represented as `int`)
* `long`
* `null`
* `text`
* `unsigned_long`
* `version`

[discrete]
==== Unsupported types

{esql} does not yet support the following field types:

* TSDB metrics
** `counter`
** `position`
** `aggregate_metric_double`
* Geo/spatial
** `geo_point`
** `geo_shape`
** `point`
** `shape`
* Date/time
** `date_nanos`
** `date_range`
* Other types
** `binary`
** `completion`
** `dense_vector`
** `double_range`
** `float_range`
** `histogram`
** `integer_range`
** `ip_range`
** `long_range`
** `nested`
** `rank_feature`
** `rank_features`
** `search_as_you_type`

Querying a column with an unsupported type returns an error. If a column with an
unsupported type is not explicitly used in a query, it is returned with `null`
values, with the exception of nested fields. Nested fields are not returned at
all.

[discrete]
[[esql-limitations-text-fields]]
=== `text` fields behave like `keyword` fields

While {esql} supports <<text,`text`>> fields, {esql} does not treat these fields
like the Search API does. {esql} queries do not query or aggregate the
<<analysis,analyzed string>>. Instead, an {esql} query will try to get a `text`
field's subfield of the <<keyword,keyword family type>> and query/aggregate
that. If it's not possible to retrieve a `keyword` subfield, {esql} will get the
string from a document's `_source`. If the `_source` cannot be retrieved, for
example when using synthetic source, `null` is returned.

Note that {esql}'s retrieval of `keyword` subfields may have unexpected
consequences. An {esql} query on a `text` field is case-sensitive. Furthermore,
a subfield may have been mapped with a <<normalizer,normalizer>>, which can
transform the original string. Or it may have been mapped with <<ignore-above>>,
which can truncate the string. None of these mapping operations are applied to
an {esql} query, which may lead to false positives or negatives. 

To avoid these issues, a best practice is to be explicit about the field that
you query, and query `keyword` sub-fields instead of `text` fields.

[discrete]
[[esql-tsdb]]
=== Time series data streams are not supported

{esql} does not support querying time series data streams (TSDS).

[discrete]
[[esql-limitations-date-math]]
=== Date math limitations

Date math expressions work well when the leftmost expression is a datetime, for
example:
[source,txt]
----
now() + 1 year - 2hour + ...
----

But using parentheses or putting the datetime to the right is not always supported yet. For example, the following expressions fail:
[source,txt]
----
1year + 2hour + now()
now() + (1year + 2hour)
----

Date math does not allow subtracting two datetimes, for example:
[source,txt]
----
now() - 2023-10-26
----

[discrete]
[[esql-limitations-enrich]]
=== Enrich limitations

include::esql-enrich-data.asciidoc[tag=limitations]

[discrete]
[[esql-limitations-kibana]]
=== Kibana limitations

include::esql-kibana.asciidoc[tag=limitations]