fix: Change datatype of column type in BaseColumn to allow larger datatype names for complexed columns

UPDATING.md

@@ -38,6 +38,7 @@ assists people when migrating to a new version.
 - [17539](https://github.com/apache/superset/pull/17539): all Superset CLI commands
   (init, load_examples and etc) require setting the FLASK_APP environment variable
   (which is set by default when .flaskenv is loaded)
+- [17360](https://github.com/apache/superset/pull/17360): changes the column type from `VARCHAR(32)` to `TEXT` in table `table_columns`, potentially requiring a table lock on MySQL dbs or taking some time to complete on large deployments.
 
 ### Deprecations
 

superset/connectors/base/models.py

@@ -578,7 +578,7 @@ class BaseColumn(AuditMixinNullable, ImportExportMixin):
     column_name = Column(String(255), nullable=False)
     verbose_name = Column(String(1024))
     is_active = Column(Boolean, default=True)
-    type = Column(String(32))
+    type = Column(Text)
     groupby = Column(Boolean, default=True)
     filterable = Column(Boolean, default=True)
     description = Column(Text)

superset/datasets/schemas.py

@@ -42,7 +42,7 @@ def validate_python_date_format(value: str) -> None:
 class DatasetColumnsPutSchema(Schema):
     id = fields.Integer()
     column_name = fields.String(required=True, validate=Length(1, 255))
-    type = fields.String(validate=Length(1, 32))
+    type = fields.String(allow_none=True)
     verbose_name = fields.String(allow_none=True, Length=(1, 1024))
     description = fields.String(allow_none=True)
     expression = fields.String(allow_none=True)

superset/migrations/versions/3ba29ecbaac5_change_datatype_of_type_in_basecolumn.py

@@ -0,0 +1,46 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""Change datatype of type in BaseColumn
+
+Revision ID: 3ba29ecbaac5
+Revises: abe27eaf93db
+Create Date: 2021-11-02 17:44:51.792138
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = "3ba29ecbaac5"
+down_revision = "abe27eaf93db"
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+
+def upgrade():
+
+    with op.batch_alter_table("table_columns") as batch_op:
+        batch_op.alter_column(
+            "type", existing_type=sa.VARCHAR(length=32), type_=sa.TEXT()
+        )
+
+
+def downgrade():
+    with op.batch_alter_table("table_columns") as batch_op:
+        batch_op.alter_column(
+            "type", existing_type=sa.TEXT(), type_=sa.VARCHAR(length=32)
+        )