diff --git a/api/src/Db/Backup.php b/api/src/Db/Backup.php
index 7527e5637e..150b286f42 100644
--- a/api/src/Db/Backup.php
+++ b/api/src/Db/Backup.php
@@ -505,9 +505,10 @@ class Backup
 	 *
 	 * @param resource $f file opened with fopen for reading
 	 * @param int|string $insert_n_rows =500 how many rows to insert in one sql statement, or string with column-name used as unique key for insert
+	 * @param bool $only_egw=false true: only restore egw_* tables, setting this to true often helps to import/update ancient EGroupware dumps
 	 * @returns int number of rows read from csv file
 	 */
-	function db_restore($f, $insert_n_rows=500)
+	function db_restore($f, $insert_n_rows=500, bool $only_egw=false)
 	{
 		$convert_to_system_charset = true;
 		$table = null;
@@ -560,7 +561,10 @@ class Backup
 					}
 					unset($def);
 					//echo "<pre>$table_name => ".self::write_array($schema,1)."</pre>\n";
-					$this->schema_proc->CreateTable($table_name, $schema);
+					if (!$only_egw || preg_match('/^egw_/', $table_name))
+					{
+						$this->schema_proc->CreateTable($table_name, $schema);
+					}
 				}
 				continue;
 			}
@@ -594,7 +598,7 @@ class Backup
 			}
 			if ($table)	// do we already reached the data part
 			{
-				$import = true;
+				$import = !$only_egw || (bool)preg_match('/^egw_/', $table_name);
 				$data = self::csv_split($line, $cols, $blobs, $bools);
 
 				if ($table == 'egw_async' && in_array('##last-check-run##',$data))
@@ -882,7 +886,7 @@ class Backup
 		//echo "function backup($f)<br>";	// !
 		@set_time_limit(0);
 		$dir = $this->files_dir; // $GLOBALS['egw_info']['server']['files_dir'];
-		// we may have to clean up old backup - left overs
+		// we may have to clean up old backup - leftovers
 		if (is_dir($dir.'/database_backup'))
 		{
 			self::remove_dir_content($dir.'/database_backup/');
diff --git a/api/src/Db/Schema.php b/api/src/Db/Schema.php
index 356ebbdb90..2774319a66 100644
--- a/api/src/Db/Schema.php
+++ b/api/src/Db/Schema.php
@@ -1330,7 +1330,7 @@ class Schema
 							{
 								$definition['fd'][$name]['precision'] = 8;
 							}
-							elseif ($column->max_length > 6 || !$column->max_length)
+							elseif ($column->max_length > 6 || $column->max_length <= 0)
 							{
 								$definition['fd'][$name]['precision'] = 4;
 							}
diff --git a/composer.lock b/composer.lock
index 658989bb9b..cfea48ae79 100644
--- a/composer.lock
+++ b/composer.lock
@@ -799,16 +799,16 @@
         },
         {
             "name": "egroupware/adodb-php",
-            "version": "5.20.6",
+            "version": "5.20.7",
             "source": {
                 "type": "git",
                 "url": "https://github.com/EGroupware/ADOdb.git",
-                "reference": "c9a0b97038104af27336c2f752dc4216cbccf7bf"
+                "reference": "2bc7b262d9739c2869d53a120822fc6efeb63a44"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/EGroupware/ADOdb/zipball/c9a0b97038104af27336c2f752dc4216cbccf7bf",
-                "reference": "c9a0b97038104af27336c2f752dc4216cbccf7bf",
+                "url": "https://api.github.com/repos/EGroupware/ADOdb/zipball/2bc7b262d9739c2869d53a120822fc6efeb63a44",
+                "reference": "2bc7b262d9739c2869d53a120822fc6efeb63a44",
                 "shasum": ""
             },
             "require": {
@@ -853,7 +853,7 @@
                 "issues": "https://github.com/ADOdb/ADOdb/issues",
                 "source": "https://github.com/ADOdb/ADOdb"
             },
-            "time": "2022-04-26T06:46:16+00:00"
+            "time": "2022-11-01T17:36:51+00:00"
         },
         {
             "name": "egroupware/bookmarks",
@@ -12332,5 +12332,5 @@
     "platform-overrides": {
         "php": "7.4"
     },
-    "plugin-api-version": "2.3.0"
+    "plugin-api-version": "2.2.0"
 }