store: Create postponed indexes non-concurrently for copy/graft

At the point where we create the postponed indexes during copying, nothing
else is writing to the subgraph and we can't be blocking a writer with a
normal 'create index'. Since concurrent index creation has to wait for all
previous transactions in the database to finish, the concurrent creation
can significantly slow down index creation and therefore how long the copy
takes.

Author: lutter

store/postgres/src/copy.rs

@@ -730,7 +730,7 @@ impl Connection {
                 &table.src.name.to_string(),
                 &table.dst,
                 true,
-                true,
+                false,
             )?;
 
             for (_, sql) in arr {
@@ -748,7 +748,11 @@ impl Connection {
                 .iter()
                 .map(|c| c.name.to_string())
                 .collect_vec();
-            for sql in table.dst.create_postponed_indexes(orig_colums).into_iter() {
+            for sql in table
+                .dst
+                .create_postponed_indexes(orig_colums, false)
+                .into_iter()
+            {
                 let query = sql_query(sql);
                 query.execute(conn)?;
             }

store/postgres/src/relational/ddl.rs

@@ -269,7 +269,11 @@ impl Table {
         (method, index_expr)
     }
 
-    pub(crate) fn create_postponed_indexes(&self, skip_colums: Vec<String>) -> Vec<String> {
+    pub(crate) fn create_postponed_indexes(
+        &self,
+        skip_colums: Vec<String>,
+        concurrently: bool,
+    ) -> Vec<String> {
         let mut indexing_queries = vec![];
         let columns = self.columns_to_index();
 
@@ -281,8 +285,9 @@ impl Table {
                 && column.name.as_str() != "id"
                 && !skip_colums.contains(&column.name.to_string())
             {
+                let conc = if concurrently { "concurrently " } else { "" };
                 let sql = format!(
-                    "create index concurrently if not exists attr_{table_index}_{column_index}_{table_name}_{column_name}\n    on {qname} using {method}({index_expr});\n",
+                    "create index {conc}if not exists attr_{table_index}_{column_index}_{table_name}_{column_name}\n    on {qname} using {method}({index_expr});\n",
                     table_index = self.position,
                     table_name = self.name,
                     column_name = column.name,

store/postgres/src/relational/ddl_tests.rs

@@ -158,7 +158,7 @@ fn generate_postponed_indexes() {
     let layout = test_layout(THING_GQL);
     let table = layout.table(&SqlName::from("Scalar")).unwrap();
     let skip_colums = vec!["id".to_string()];
-    let query_vec = table.create_postponed_indexes(skip_colums);
+    let query_vec = table.create_postponed_indexes(skip_colums, true);
     assert!(query_vec.len() == 7);
     let queries = query_vec.join(" ");
     check_eqv(THING_POSTPONED_INDEXES, &queries)