diff --git a/packages/nocodb/src/db/sql-client/lib/pg/PgClient.ts b/packages/nocodb/src/db/sql-client/lib/pg/PgClient.ts
index ef94e4e07d..39481e6d44 100644
--- a/packages/nocodb/src/db/sql-client/lib/pg/PgClient.ts
+++ b/packages/nocodb/src/db/sql-client/lib/pg/PgClient.ts
@@ -965,28 +965,13 @@ class PGClient extends KnexClient {
       f.attnotnull as rqd,
       p.contype as cst,
       p.conname as cstn,
+      ix.indisprimary as primarykey,
+      not ix.indisunique as non_unique_original,
+      not ix.indisunique as non_unique,
       CASE
           WHEN i.oid<>0 THEN true
           ELSE false
       END AS is_index,
-      CASE
-          WHEN p.contype = 'p' THEN true
-          ELSE false
-      END AS primarykey,
-      CASE
-          WHEN p.contype = 'u' THEN 0
-      WHEN p.contype = 'p' THEN 0
-          ELSE 1
-      END AS non_unique_original,
-      CASE
-          WHEN p.contype = 'p' THEN true
-          ELSE false
-      END AS primarykey,
-      CASE
-          WHEN p.contype = 'u' THEN 0
-      WHEN p.contype = 'p' THEN 0
-          ELSE 1
-      END AS non_unique,
       CASE
           WHEN f.atthasdef = 't' THEN pg_get_expr(d.adbin, d.adrelid)
       END AS default  FROM pg_attribute f
diff --git a/packages/nocodb/src/services/columns.service.ts b/packages/nocodb/src/services/columns.service.ts
index db75073e82..34d7655944 100644
--- a/packages/nocodb/src/services/columns.service.ts
+++ b/packages/nocodb/src/services/columns.service.ts
@@ -2059,6 +2059,7 @@ export class ColumnsService {
       req?: any;
       columnId: string;
       user: UserType;
+      forceDeleteSystem?: boolean;
       reuse?: ReusableParams;
     },
     ncMeta = this.metaService,
@@ -2067,7 +2068,7 @@ export class ColumnsService {
 
     const column = await Column.get({ colId: param.columnId }, ncMeta);
 
-    if (column.system) {
+    if (column.system && !param.forceDeleteSystem) {
       NcError.badRequest(
         `The column '${
           column.title || column.column_name
@@ -2424,7 +2425,7 @@ export class ColumnsService {
             ...index,
             tn: cTable.table_name,
             columns: [childColumn.column_name],
-            indexName: index.index_name,
+            indexName: index.key_name,
           });
         }
       }
diff --git a/packages/nocodb/src/services/tables.service.ts b/packages/nocodb/src/services/tables.service.ts
index f0a6552c22..40e7e190ef 100644
--- a/packages/nocodb/src/services/tables.service.ts
+++ b/packages/nocodb/src/services/tables.service.ts
@@ -202,7 +202,7 @@ export class TablesService {
       // delete all relations
       for (const c of relationColumns) {
         // skip if column is hasmany relation to mm table
-        if (c.system) {
+        if (c.system && !table.mm) {
           continue;
         }
 
@@ -216,6 +216,7 @@ export class TablesService {
             req: param.req,
             columnId: c.id,
             user: param.user,
+            forceDeleteSystem: true,
           },
           ncMeta,
         );