Configure postgres fts backend

modules/joex/src/main/resources/reference.conf

@@ -697,6 +697,9 @@ Docpell Update Check
     # Currently the SOLR search platform is supported.
     enabled = false
 
+    # Which backend to use, either solr or postgresql
+    backend = "solr"
+
     # Configuration for the SOLR backend.
     solr = {
       # The URL to solr
@@ -713,6 +716,43 @@ Docpell Update Check
       q-op = "OR"
     }
 
+    # Configuration for PostgreSQL backend
+    postgresql = {
+      # Whether to use the default database, only works if it is
+      # postgresql
+      use-default-connection = false
+
+      # The database connection.
+      jdbc {
+        url = "jdbc:postgresql://server:5432/db"
+        user = "pguser"
+        password = ""
+      }
+
+      # A mapping from a language to a postgres text search config. By
+      # default a language is mapped to a predefined config.
+      # PostgreSQL has predefined configs for some languages. This
+      # setting allows to create a custom text search config and
+      # define it here for some or all languages.
+      #
+      # Example:
+      #  { german = "my-german" }
+      #
+      # See https://www.postgresql.org/docs/14/textsearch-tables.html ff.
+      pg-config = {
+      }
+
+      # Define which query parser to use.
+      #
+      # https://www.postgresql.org/docs/14/textsearch-controls.html#TEXTSEARCH-PARSING-QUERIES
+      pg-query-parser = "websearch_to_tsquery"
+
+      # Allows to define a normalization for the ranking.
+      #
+      # https://www.postgresql.org/docs/14/textsearch-controls.html#TEXTSEARCH-RANKING
+      pg-rank-normalization = [ 4 ]
+    }
+
     # Settings for running the index migration tasks
     migration = {
       # Chunk size to use when indexing data from the database. This