docs/api/sql/Parameter.md

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## Usage

SedonaSQL supports many parameters. To change their values,

1. Set it through SparkConf:

```scala
sparkSession = SparkSession.builder().
      config("spark.serializer","org.apache.spark.serializer.KryoSerializer").
      config("spark.kryo.registrator", "org.apache.sedona.core.serde.SedonaKryoRegistrator").
      config("sedona.global.index","true")
      master("local[*]").appName("mySedonaSQLdemo").getOrCreate()
```

2. Check your current SedonaSQL configuration:

```scala
val sedonaConf = new SedonaConf(sparkSession.conf)
println(sedonaConf)
```

3. Sedona parameters can be changed at runtime:

```scala
sparkSession.conf.set("sedona.global.index","false")
```

In addition, you can also add `spark` prefix to the parameter name, for example:

```scala
sparkSession.conf.set("spark.sedona.global.index","false")
```

However, any parameter set through `spark` prefix will be honored by Spark, which means you can set these parameters before hand via `spark-defaults.conf` or Spark on Kubernetes configuration.

If you set the same parameter through both `sedona` and `spark.sedona` prefixes, the parameter set through `sedona` prefix will override the parameter set through `spark.sedona` prefix.

## General Parameters

| Parameter | Description | Default | Possible Values |
| :--- | :--- | :--- | :--- |
| `sedona.global.index` | Use spatial index (currently, only supports in SQL range join and SQL distance join) | `true` | `true`, `false` |
| `sedona.global.indextype` | Spatial index type, only valid when `sedona.global.index` is true | `rtree` | `rtree`, `quadtree` |
| `spark.sedona.enableParserExtension` | Enable the parser extension to parse GEOMETRY data type in SQL DDL statements | `true` | `true`, `false` |

## Join Parameters

| Parameter | Description | Default | Possible Values |
| :--- | :--- | :--- | :--- |
| `sedona.join.autoBroadcastJoinThreshold` | Maximum size in bytes for a table that will be broadcast to all worker nodes when performing a join. Set to -1 to disable automatic broadcasting. | Same as `spark.sql.autoBroadcastJoinThreshold` | Any integer with a byte suffix, e.g. `10MB` or `512KB` |
| `sedona.join.gridtype` | Spatial partitioning grid type for join query | `kdbtree` | `quadtree`, `kdbtree` |
| `spark.sedona.join.knn.includeTieBreakers` | KNN join will include all ties in the result, possibly returning more than k results | `false` | `true`, `false` |
| `sedona.join.indexbuildside` | **(Advanced)** The side which Sedona builds spatial indices on | `left` | `left`, `right` |
| `sedona.join.numpartition` | **(Advanced)** Number of partitions for both sides in a join query | `-1` (use existing partitions) | Any integer |
| `sedona.join.spatitionside` | **(Advanced)** The dominant side in spatial partitioning stage | `left` | `left`, `right` |
| `sedona.join.optimizationmode` | **(Advanced)** When Sedona should optimize spatial join SQL queries | `nonequi` | `all` (always optimize, even equi-joins), `none` (disable optimization), `nonequi` (optimize non-equi-joins only) |

## CRS Transformation Parameters

| Parameter | Description | Default | Possible Values | Since |
| :--- | :--- | :--- | :--- | :--- |
| `spark.sedona.crs.geotools` | Controls which library is used for CRS transformations in ST_Transform | `raster` | `none` (proj4sedona for all), `raster` (proj4sedona for vector, GeoTools for raster), `all` (GeoTools for all — legacy) | v1.9.0 |
| `spark.sedona.crs.url.base` | Base URL of a CRS definition server for resolving authority codes (e.g., EPSG) via HTTP. When set, ST_Transform will consult this URL provider before the built-in definitions. | _(empty — disabled)_ | e.g. `https://crs.example.com` | v1.9.0 |
| `spark.sedona.crs.url.pathTemplate` | URL path template appended to `spark.sedona.crs.url.base`. Placeholders `{authority}` and `{code}` are replaced at runtime. | `/{authority}/{code}.json` | e.g. `/epsg/{code}.json` | v1.9.0 |
| `spark.sedona.crs.url.format` | The CRS definition format returned by the URL provider | `projjson` | `projjson`, `proj`, `wkt1` (OGC WKT1), `wkt2` (ISO 19162 WKT2) | v1.9.0 |