[ci skip] Fix 5423
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 7fb258a..5779c87 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -224,8 +224,8 @@
 		 * and so we'll have to fall back to running a query in
 		 * order to get it.
 		 */
-		return isset($pg_version['server'])
-			? $this->data_cache['version'] = $pg_version['server']
+		return (isset($pg_version['server']) && preg_match('#^(\d+\.\d+)#', $pg_version['server'], $match))
+			? $this->data_cache['version'] = $match[1]
 			: parent::version();
 	}
 
@@ -354,8 +354,7 @@
 	 */
 	public function insert_id()
 	{
-		$v = pg_version($this->conn_id);
-		$v = isset($v['server']) ? $v['server'] : 0; // 'server' key is only available since PosgreSQL 7.4
+		$v = $this->version();
 
 		$table	= (func_num_args() > 0) ? func_get_arg(0) : NULL;
 		$column	= (func_num_args() > 1) ? func_get_arg(1) : NULL;
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 2b82d7b..37291e1 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -14,12 +14,14 @@
 -  General Changes
 
    -  Updated :doc:`Email Library <libraries/email>` to always negotiate between TLS 1.0, 1.1, 1.2 when possible (PHP 5.6+) for SMTP connections.
+   -  Updated :doc:`Database Library <database/index>` method ``version()`` to exclude suffixes to the main version numbers with the 'postgre' driver.
 
 Bug fixes for 3.1.8
 -------------------
 
 -  Fixed a bug where :doc:`Form Validation Library <libraries/form_validation>`, :doc:`Email Library <libraries/email>` tried to use ``INTL_IDNA_VARIANT_UTS46`` when it was undeclared.
 -  Fixed a bug where :doc:`Query Builder <database/query_builder>` methods ``where()``, ``having()`` treated values passed to them as arbitrary SQL.
+-  Fixed a bug (#5423) - :doc:`Database Library <database/index>` method ``insert_id()`` failed due to incorrect server version parsing with the 'postgre' driver.
 
 Version 3.1.7
 =============