MDL-79926 dml: Add explain to log_queries info field

SysBind · Oct 31, 2023 · b2592a8 · b2592a8
1 parent 859df15
commit b2592a8
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Showing 6 changed files with 341 additions and 143 deletions.
diff --git a/lib/dml/moodle_database.php b/lib/dml/moodle_database.php
@@ -539,7 +539,7 @@ public function query_log($error=false) {
                 $log->sqltext    = $this->last_sql;
                 $log->sqlparams  = var_export((array)$this->last_params, true);
                 $log->error      = (int)$iserror;
-                $log->info       = $iserror ? $error : null;
+                $log->info       = $iserror ? $error : var_export($this->query_log_explain(), true);
                 $log->backtrace  = format_backtrace($backtrace, true);
                 $log->exectime   = $time;
                 $log->timelogged = time();
@@ -550,6 +550,13 @@ public function query_log($error=false) {
         }
     }
 
+    /**
+     * Get Last query explain.
+     *
+     * @return array
+     */
+    abstract protected function query_log_explain(): array;
+
     /**
      * Disable logging temporarily.
      */

diff --git a/lib/dml/mysqli_native_moodle_database.php b/lib/dml/mysqli_native_moodle_database.php
@@ -416,6 +416,32 @@ public function is_compressed_row_format_supported($cached = true) {
         return $this->compressedrowformatsupported;
     }
 
+    /**
+     * Get Last query explain.
+     *
+     * @return array
+     */
+    protected function query_log_explain(): array {
+        list($sql, $params, $type) = $this->fix_sql_params($this->last_sql, $this->last_params);
+
+        if (strpos($sql, ';') !== false) {
+            throw new coding_exception('moodle_database::execute() Multiple sql statements found or
+                bound parameters not used properly in query!');
+        }
+
+        $rawsql = $this->emulate_bound_params($sql, $params);
+        $explain = [];
+        $result = $this->mysqli->query('EXPLAIN ' . $rawsql);
+        foreach ($result as $rs) {
+            $explain[] = $rs;
+        }
+        if ($result !== true) {
+            $result->close();
+        }
+
+        return $explain;
+    }
+
     /**
      * Check the database to see if innodb_file_per_table is on.
      *

diff --git a/lib/dml/oci_native_moodle_database.php b/lib/dml/oci_native_moodle_database.php
@@ -1102,6 +1102,29 @@ protected function create_recordset($stmt) {
         return new oci_native_moodle_recordset($stmt);
     }
 
+    /**
+     * Get Last query explain.
+     *
+     * @return array
+     */
+    protected function query_log_explain(): array {
+        list($rawsql, $params, $type) = $this->fix_sql_params($this->last_sql, $this->last_params);
+
+        list($rawsql, $params) = $this->tweak_param_names($rawsql, $params);
+
+        $explain = [];
+        $stmt = $this->parse_query('EXPLAIN ' . $rawsql);
+        $descriptors = [];
+        $this->bind_params($stmt, $params, null, $descriptors);
+        $result = oci_execute($stmt, $this->commit_status);
+        $this->free_descriptors($descriptors);
+        foreach ($this->create_recordset($stmt) as $rs) {
+            $explain[] = $rs;
+        }
+
+        return $explain;
+    }
+
     /**
      * Get a number of records as an array of objects using a SQL statement.
      *

diff --git a/lib/dml/pdo_moodle_database.php b/lib/dml/pdo_moodle_database.php
@@ -285,6 +285,35 @@ public function get_recordset_sql($sql, array $params=null, $limitfrom=0, $limit
         return $result;
     }
 
+    /**
+     * Get Last query explain.
+     *
+     * @return array
+     * @throws coding_exception
+     * @throws ddl_change_structure_exception
+     * @throws dml_exception
+     * @throws dml_read_exception
+     * @throws dml_write_exception
+     */
+    protected function query_log_explain(): array {
+        list($sql, $params, $type) = $this->fix_sql_params($this->last_sql, $this->last_params);
+        $sql = 'EXPLAIN ' . $sql;
+        try {
+            $sth = $this->pdb->prepare($sql);
+            $sth->execute($params);
+            $result = $this->create_recordset($sth);
+        } catch (PDOException $ex) {
+            $this->lastError = $ex->getMessage();
+            $result = false;
+        }
+        $explain = [];
+        foreach ($result as $rs) {
+            $explain[] = $rs;
+        }
+
+        return $explain;
+    }
+
     /**
      * Selects rows and return values of first column as array.
      *