Use JDBC metadata fn to fetch MATERIALIZED VIEWS (credit: @lindsay-stevens)

src/metabase/driver/generic_sql.clj

@@ -15,7 +15,7 @@
             [metabase.sync-database.analyze :as analyze]
             [metabase.util :as u]
             [metabase.util.honeysql-extensions :as hx])
-  (:import java.sql.DatabaseMetaData
+  (:import (java.sql DatabaseMetaData ResultSet)
            java.util.Map
            (clojure.lang Keyword PersistentVector)
            com.mchange.v2.c3p0.ComboPooledDataSource
@@ -327,7 +327,6 @@
 
 ;;; ## Database introspection methods used by sync process
 
-;; TODO - clojure.java.jdbc now ships with a `metadata-query` function we could use here. See #2918
 (defmacro with-metadata
   "Execute BODY with `java.sql.DatabaseMetaData` for DATABASE."
   [[binding _ database] & body]
@@ -335,6 +334,12 @@
      (let [~binding (.getMetaData conn#)]
        ~@body)))
 
+(defn- get-tables
+  "Fetch a JDBC Metadata ResultSet of tables in the DB, optionally limited to ones belonging to a given schema."
+  ^ResultSet [^DatabaseMetaData metadata, ^String schema-or-nil]
+  (jdbc/result-set-seq (.getTables metadata nil schema-or-nil "%" ; tablePattern "%" = match all tables
+                                   (into-array String ["TABLE", "VIEW", "FOREIGN TABLE", "MATERIALIZED VIEW"]))))
+
 (defn fast-active-tables
   "Default, fast implementation of `ISQLDriver/active-tables` best suited for DBs with lots of system tables (like Oracle).
    Fetch list of schemas, then for each one not in `excluded-schemas`, fetch its Tables, and combine the results.
@@ -344,7 +349,7 @@
   (let [all-schemas (set (map :table_schem (jdbc/result-set-seq (.getSchemas metadata))))
         schemas     (set/difference all-schemas (excluded-schemas driver))]
     (set (for [schema     schemas
-               table-name (mapv :table_name (jdbc/result-set-seq (.getTables metadata nil schema "%" (into-array String ["TABLE", "VIEW", "FOREIGN TABLE"]))))] ; tablePattern "%" = match all tables
+               table-name (mapv :table_name (get-tables metadata schema))]
            {:name   table-name
             :schema schema}))))
 
@@ -353,7 +358,7 @@
    Fetch *all* Tables, then filter out ones whose schema is in `excluded-schemas` Clojure-side."
   [driver, ^DatabaseMetaData metadata]
   (set (for [table (filter #(not (contains? (excluded-schemas driver) (:table_schem %)))
-                           (jdbc/result-set-seq (.getTables metadata nil nil "%" (into-array String ["TABLE", "VIEW", "FOREIGN TABLE"]))))] ; tablePattern "%" = match all tables
+                           (get-tables metadata nil))]
          {:name   (:table_name table)
           :schema (:table_schem table)})))
 

src/metabase/driver/postgres.clj

@@ -180,23 +180,6 @@
       (isa? base-type :type/IPAddress) (hx/cast :inet value)
       :else                            value)))
 
-
-(defn- materialized-views
-  "Fetch the Materialized Views for a Postgres DATABASE.
-   These are returned as a set of maps, the same format as `:tables` returned by `describe-database`."
-  [database]
-  (try (set (jdbc/query (sql/db->jdbc-connection-spec database)
-                        ["SELECT schemaname AS \"schema\", matviewname AS \"name\" FROM pg_matviews;"]))
-       (catch Throwable e
-         (log/error "Failed to fetch materialized views for this database:" (.getMessage e)))))
-
-(defn- describe-database
-  "Custom implementation of `describe-database` for Postgres.
-   Postgres Materialized Views are not returned by normal JDBC methods: see [issue #2355](https://github.com/metabase/metabase/issues/2355); we have to manually fetch them.
-   This implementation combines the results from the generic SQL default implementation with materialized views fetched from `materialized-views`."
-  [driver database]
-  (update (sql/describe-database driver database) :tables (u/rpartial set/union (materialized-views database))))
-
 (defn- string-length-fn [field-key]
   (hsql/call :char_length (hx/cast :VARCHAR field-key)))
 
@@ -221,7 +204,6 @@
   driver/IDriver
   (merge (sql/IDriverSQLDefaultsMixin)
          {:date-interval                     (u/drop-first-arg date-interval)
-          :describe-database                 describe-database
           :details-fields                    (constantly [{:name         "host"
                                                            :display-name "Host"
                                                            :default      "localhost"}