HANA

The HANA provider manages querying for tile requests against an SAP HANA database. The connection between tegola and HANA is configured in a tegola.toml file. An example minimum connection config:

[[providers]]
name = "test_hana"       # provider name is referenced from map layers (required)
type = "hana"            # the type of data provider must be "hana" for this data provider (required)
uri = "hdb://myuser:[email protected]:443?" # HANA connection string (required)

Connection Properties

• uri (string): [Required] HANA connection string
• name (string): [Required] provider name is referenced from map layers
• type (string): [Required] the type of data provider. must be "hana" to use this data provider
• srid (int): [Optional] The default SRID for the provider. Defaults to WebMercator (3857) but also supports WGS84 (4326)

Connection string properties

Example

# {protocol}://{user}:{password}@{host}:{port}/{database}?{options}=
hdb://myuser:[email protected]:443?TLSInsecureSkipVerify&timeout=3600&max_connections=30

Options

• timeout: [Optional] Driver side connection timeout in seconds.
• TLSRootCAFile [Optional] Path,- filename to root certificate(s).
• TLSServerName [Optional] ServerName to verify the hostname. By setting TLSServerName=host, the provider will set TLSServerName same as 'host' value in uri.
• TLSInsecureSkipVerify [Optional] Controls whether a client verifies the server's certificate chain and host name.
• max_connections: [Optional] The max connections to maintain in the connection pool. Defaults to 100. 0 means no max.
• max_connection_idle_time: [Optional] The maximum time an idle connection is kept alive. Defaults to "30m".
• max_connection_life_time [Optional] The maximum time a connection lives before it is terminated and recreated. Defaults to "1h".

Provider Layers

In addition to the connection configuration above, Provider Layers need to be configured. A Provider Layer tells tegola how to query HANA for a certain layer. An example minimum config:

[[providers.layers]]
name = "landuse"
# this table uses "geom" for the geometry_fieldname and "gid" for the id_fieldname so they don't need to be configured
tablename = "gis.zoning_base_3857"

Provider Layers Properties

• name (string): [Required] the name of the layer. This is used to reference this layer from map layers.
• tablename (string): [*Required] the name of the database table to query against. Required if sql is not defined.
• geometry_fieldname (string): [Optional] the name of the filed which contains the geometry for the feature. defaults to geom.
• id_fieldname (string): [Optional] the name of the feature id field. defaults to gid.
• fields ([]string): [Optional] a list of fields to include alongside the feature. Can be used if sql is not defined.
• srid (int): [Optional] the SRID of the layer. Supports 3857 (WebMercator) or 4326 (WGS84).
• geometry_type (string): [Optional] the layer geometry type. If not set, the table will be inspected at startup to try and infer the gemetry type. Valid values are: Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, GeometryCollection.
• sql (string): [*Required] custom SQL to use use. Required if tablename is not defined. Supports the following tokens:
  • !BBOX! - [Required] will be replaced with the bounding box of the tile before the query is sent to the database. !bbox! and!BOX! are supported as well for compatibilitiy with queries from Mapnik and MapServer styles.
  • !ZOOM! - [Optional] will be replaced with the "Z" (zoom) value of the requested tile.
  • !X! - [Optional] will be replaced with the "X" value of the requested tile.
  • !Y! - [Optional] will be replaced with the "Y" value of the requested tile.
  • !Z! - [Optional] will be replaced with the "Z" value of the requested tile.
  • !SCALE_DENOMINATOR! - [Optional] scale denominator, assuming 90.7 DPI (i.e. 0.28mm pixel size).
  • !PIXEL_WIDTH! - [Optional] the pixel width in meters, assuming 256x256 tiles.
  • !PIXEL_HEIGHT! - [Optional] the pixel height in meters, assuming 256x256 tiles.
  • !ID_FIELD! - [Optional] the id field name.
  • !GEOM_FIELD! - [Optional] the geom field name.
  • !GEOM_TYPE! - [Optional] the geom type field name.

*Required: either the tablename or sql must be defined, but not both.

Example minimum custom SQL config

[[providers.layers]]
name = "rivers"
# Custom sql to be used for this layer as a sub query. ST_AsBinary and !BBOX! filter are applied automatically.
sql = "(SELECT id, geom FROM gis.rivers) AS sub"

Environment Variable support

Helpful debugging environment variables:

• TEGOLA_SQL_DEBUG: specify the type of SQL debug information to output. Supports the following values:
  • LAYER_SQL: print layer SQL as they’re parsed from the config file.
  • EXECUTE_SQL: print SQL that is executed for each tile request and the number of items it returns or an error.
  • LAYER_SQL:EXECUTE_SQL: print LAYER_SQL and EXECUTE_SQL.

Example:

$ TEGOLA_SQL_DEBUG=LAYER_SQL tegola serve --config=/path/to/conf.toml

Testing

Testing is designed to work against a live SAP HANA database. To see how to set up a database check this github actions script. To run the HANA tests, the following environment variables need to be set:

$ export RUN_HANA_TESTS=yes
$ export HANA_CONNECTION_STRING="hdb://myuser:[email protected]:443?TLSInsecureSkipVerify"