fix: match SQL Server schema names case-sensitively in profiling DDF

On SQL Server's default (case-insensitive) collation, a table group whose
configured schema case differs from the database's actual case (e.g. 'common'
vs 'Common') silently broke Freshness monitor generation and Data Catalog
stats. Profiling stamps profile_results.schema_name with the entered literal
while the DDF stamps data_table_chars/data_column_chars with the DB's actual
case, so the case-sensitive PostgreSQL joins between them returned nothing;
Volume_Trend (data_table_chars only) still worked, masking it.

Add COLLATE Latin1_General_BIN to the schema comparison in the mssql
get_schema_ddf so matching is case-sensitive, consistent with TestGen's
case-sensitive joins and the other flavors. Migration 0194 realigns existing
table_group_schema values to the DB's actual case (from data_table_chars),
scoped to mssql connections, single unambiguous schema, case-only differences.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: aarthy-dk

testgen/template/dbupgrade/0194_incremental_upgrade.sql

@@ -0,0 +1,34 @@
+SET SEARCH_PATH TO {SCHEMA_NAME};
+
+-- Schema-name matching in the SQL Server DDF query is now case-sensitive,
+-- consistent with TestGen's case-sensitive joins and the other flavors. 
+-- A case-insensitive source previously accepted a table
+-- group whose configured schema name differed in case from the database;
+-- such a group would now match no tables on its next profiling run.
+--
+-- data_table_chars.schema_name holds the case the source database actually
+-- reported (it is populated from the DDF's c.table_schema, not the entered
+-- value), so realign table_group_schema to that case. Guards:
+--   * only mssql connections -- the DDF change was made only for that flavor,
+--   * only when the catalog reports a single unambiguous schema for the group,
+--   * only a case-only difference (LOWER() match), never a different schema,
+--   * '<>' is case-sensitive in PostgreSQL, so correct rows are left untouched.
+-- After this, the group's next profiling run stamps profile_results with the
+-- corrected case, realigning the case-sensitive downstream joins.
+UPDATE table_groups tg
+SET table_group_schema = actual.schema_name
+FROM (
+    SELECT table_groups_id, MIN(schema_name) AS schema_name
+    FROM data_table_chars
+    WHERE drop_date IS NULL
+    GROUP BY table_groups_id
+    HAVING COUNT(DISTINCT schema_name) = 1
+) actual
+WHERE actual.table_groups_id = tg.id
+  AND tg.table_group_schema <> actual.schema_name
+  AND LOWER(tg.table_group_schema) = LOWER(actual.schema_name)
+  AND EXISTS (
+      SELECT 1 FROM connections cn
+      WHERE cn.connection_id = tg.connection_id
+        AND cn.sql_flavor = 'mssql'
+  );

testgen/template/flavors/mssql/data_chars/get_schema_ddf.sql

@@ -54,5 +54,5 @@ SELECT
 FROM information_schema.columns c
     LEFT JOIN approx_cts a ON c.table_schema = a.schema_name AND c.table_name = a.table_name
     LEFT JOIN information_schema.tables it ON c.table_schema = it.table_schema AND c.table_name = it.table_name
-WHERE c.table_schema = '{DATA_SCHEMA}' {TABLE_CRITERIA}
+WHERE c.table_schema = '{DATA_SCHEMA}' COLLATE Latin1_General_BIN {TABLE_CRITERIA}
 ORDER BY c.table_schema, c.table_name, c.ordinal_position;