allowing the index type to be specified in the Column definition

Author: dantownsend

piccolo/columns/base.py

@@ -31,8 +31,9 @@
 from piccolo.utils.warnings import colored_warning
 
 if t.TYPE_CHECKING:  # pragma: no cover
-    from piccolo.table import Table
     from piccolo.columns.column_types import ForeignKey
+    from piccolo.query.methods.create_index import IndexMethod
+    from piccolo.table import Table
 
 
 class OnDelete(str, Enum):
@@ -119,7 +120,7 @@ class ColumnMeta:
     primary: bool = False
     key: bool = False
     unique: bool = False
-    index: bool = False
+    index: t.Union[IndexMethod, bool] = False
     required: bool = False
 
     # Used for representing the table in migrations and the playground.
@@ -231,8 +232,10 @@ class Column(Selectable):
         If set, a unique contraint will be added to the column.
 
     :param index:
-        If set, the an index is created for the column, which can improve
-        the speed of selects, but can slow down inserts.
+        Whether an index is created for the column, which can improve
+        the speed of selects, but can slow down inserts. If set to True, the
+        default index type is created (b-tree). If False, no index is created.
+        If an IndexMethod value is provided, that type of index is created.
 
     :param required:
         This isn't used by the database - it's to indicate to other tools that
@@ -249,7 +252,7 @@ def __init__(
         primary: bool = False,
         key: bool = False,
         unique: bool = False,
-        index: bool = False,
+        index: t.Union[IndexMethod, bool] = False,
         required: bool = False,
         **kwargs,
     ) -> None:

piccolo/query/methods/create.py

@@ -3,7 +3,7 @@
 
 from piccolo.query.base import Query
 from piccolo.querystring import QueryString
-from piccolo.query.methods.create_index import CreateIndex
+from piccolo.query.methods.create_index import CreateIndex, IndexMethod
 
 if t.TYPE_CHECKING:  # pragma: no cover
     from piccolo.table import Table
@@ -44,13 +44,22 @@ def querystrings(self) -> t.Sequence[QueryString]:
 
         create_indexes: t.List[QueryString] = []
         for column in columns:
-            if column._meta.index:
-                create_indexes.extend(
-                    CreateIndex(
-                        table=self.table,
-                        columns=[column],
-                        if_not_exists=self.if_not_exists,
-                    ).querystrings
-                )
+            if column._meta.index is False:
+                continue
+            elif column._meta.index is True:
+                method = IndexMethod.btree
+            elif isinstance(column._meta.index, IndexMethod):
+                method = column._meta.index
+            else:
+                raise ValueError("Unrecognised value for column index")
+
+            create_indexes.extend(
+                CreateIndex(
+                    table=self.table,
+                    columns=[column],
+                    method=method,
+                    if_not_exists=self.if_not_exists,
+                ).querystrings
+            )
 
         return [create_table] + create_indexes