# Supported types for partition projection
A table can have any combination of `enum`, `integer`, `date,` or `injected` partition column types.
## Enum type
Use the `enum` type for partition columns whose values are members of an enumerated set (for example, airport codes or AWS Regions).
Define the partition properties in the table as follows:
****
| Property name | Example values | Description |
| --- | --- | --- |
| projection.columnName.type | `enum` | Required. The projection type to use for column columnName. The value must be enum (case insensitive) to signal the use of the enum type. Leading and trailing white space is allowed. |
| projection.columnName.values | `A,B,C,D,E,F,G,Unknown` | Required. A comma-separated list of enumerated partition values for column columnName. Any white space is considered part of an enum value. |
**Note**
As a best practice we recommend limiting the use of `enum` based partition projections to a few dozen or less. Although there is no specific limit for `enum` projections, the total size of your table's metadata cannot exceed the AWS Glue limit of about 1 MB when gzip compressed. Note that this limit is shared across key parts of your table like column names, location, storage format, and others. If you find yourself using more than a few dozen unique IDs in your `enum` projection, consider an alternative approach such as bucketing into a smaller number of unique values in a surrogate field. By trading off cardinality, you can control the number of unique values in your `enum` field.
## Integer type
Use the integer type for partition columns whose possible values are interpretable as integers within a defined range. Projected integer columns are currently limited to the range of a Java signed long (-263 to 263-1 inclusive).
****
| Property name | Example values | Description |
| --- | --- | --- |
| projection.columnName.type | `integer` | Required. The projection type to use for column columnName. The value must be integer (case insensitive) to signal the use of the integer type. Leading and trailing white space is allowed. |
| projection.columnName.range | `0,10` `-1,8675309` `0001,9999` | Required. A two-element comma-separated list that provides the minimum and maximum range values to be returned by queries on the column columnName. Note that the values must be separated by a comma, not a hyphen. These values are inclusive, can be negative, and can have leading zeroes. Leading and trailing white space is allowed. |
| projection.columnName.interval | `1` `5` | Optional. A positive integer that specifies the interval between successive partition values for the column columnName. For example, a range value of "1,3" with an interval value of "1" produces the values 1, 2, and 3. The same range value with an interval value of "2" produces the values 1 and 3, skipping 2. Leading and trailing white space is allowed. The default is 1. |
| projection.columnName.digits | `1` `5` | Optional. A positive integer that specifies the number of digits to include in the partition value's final representation for column columnName. For example, a range value of "1,3" that has a digits value of "1" produces the values 1, 2, and 3. The same range value with a digits value of "2" produces the values 01, 02, and 03. Leading and trailing white space is allowed. The default is no static number of digits and no leading zeroes. |
## Date type
Use the date type for partition columns whose values are interpretable as dates (with optional times) within a defined range.
**Important**
Projected date columns are generated in Coordinated Universal Time (UTC) at query execution time.
****
| Property name | Example values | Description |
| --- | --- | --- |
| projection.columnName.type | `date` | Required. The projection type to use for column columnName. The value must be date (case insensitive) to signal the use of the date type. Leading and trailing white space is allowed. |
| projection.columnName.range | `201701,201812` `01-01-2010,12-31-2018` `NOW-3YEARS,NOW` `201801,NOW+1MONTH` | Required. A two-element, comma-separated list which provides the minimum and maximum `range` values for the column *columnName*. These values are inclusive and can use any format compatible with the Java `java.time.*` date types. Both the minimum and maximum values must use the same format. The format specified in the `.format` property must be the format used for these values. This column can also contain relative date strings, formatted in this regular expression pattern: `\s*NOW\s*(([\+\-])\s*([0-9]+)\s*(YEARS?\|MONTHS?\|WEEKS?\|DAYS?\|HOURS?\|MINUTES?\|SECONDS?)\s*)?` White spaces are allowed, but in date literals are considered part of the date strings themselves. |
| projection.columnName.format | `yyyyMM` `dd-MM-yyyy` `dd-MM-yyyy-HH-mm-ss` | Required. A date format string based on the Java date format [DateTimeFormatter](https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html). Can be any supported Java.time.\$1 type. |
| projection.columnName.interval | `1` `5` | A positive integer that specifies the interval between successive partition values for column *columnName*. For example, a `range` value of `2017-01,2018-12` with an `interval` value of `1` and an `interval.unit` value of `MONTHS` produces the values 2017-01, 2017-02, 2017-03, and so on. The same `range` value with an `interval` value of `2` and an `interval.unit` value of `MONTHS` produces the values 2017-01, 2017-03, 2017-05, and so on. Leading and trailing white space is allowed. When the provided dates are at single-day or single-month precision, the `interval` is optional and defaults to 1 day or 1 month, respectively. Otherwise, `interval` is required. |
| projection.columnName.interval.unit | `YEARS` `MONTHS` `WEEKS` `DAYS` `HOURS` `MINUTES` `SECONDS` `MILLIS` | A time unit word that represents the serialized form of a [ChronoUnit](https://docs.oracle.com/javase/8/docs/api/java/time/temporal/ChronoUnit.html). Possible values are `YEARS`, `MONTHS`, `WEEKS`, `DAYS`, `HOURS`, `MINUTES`, `SECONDS`, or `MILLIS`. These values are case insensitive. When the provided dates are at single-day or single-month precision, the `interval.unit` is optional and defaults to 1 day or 1 month, respectively. Otherwise, the `interval.unit` is required. |
**Example – Partitioning by month**
The following example table configuration partitions data by month from 2015 to the present.
```
'projection.month.type'='date',
'projection.month.format'='yyyy-MM',
'projection.month.interval'='1',
'projection.month.interval.unit'='MONTHS',
'projection.month.range'='2015-01,NOW',
...
```
## Injected type
Use the injected type for partition columns with possible values that cannot be procedurally generated within some logical range but that are provided in a query's `WHERE` clause as a single value.
It is important to keep in mind the following points:
+ Queries on injected columns fail if a filter expression is not provided for each injected column.
+ Queries with multiple values for a filter expression on an injected column succeed only if the values are disjunct.
+ Only columns of `string` type are supported.
+ When you use the `WHERE IN` clause with an injected partition column, there is a limit of 1,000 values that you can specify in the `IN` list. To query a dataset with more than 1,000 partitions for an injected column, split the query into multiple smaller queries, each with up to 1,000 values in the `WHERE IN` clause, and then aggregate the results.
****
| Property name | Value | Description |
| --- | --- | --- |
| projection.columnName.type | `injected` | Required. The projection type to use for the column columnName. Only the string type is supported. The value specified must be injected (case insensitive). Leading and trailing white space is allowed. |
For more information, see [When to use the `injected` projection type](partition-projection-dynamic-id-partitioning.md#partition-projection-injection).