diff -r 0f46b645aea4 -r 7c31bcd5b4be src/server/plugins/postgresql/vfs.c
--- a/src/server/plugins/postgresql/vfs.c	Sun Apr 17 11:22:34 2022 +0200
+++ b/src/server/plugins/postgresql/vfs.c	Sun Apr 17 11:51:37 2022 +0200
@@ -128,6 +128,11 @@
         ($1, $2, true, now(), now(), 0)\n\
         returning resource_id, lastmodified, creationdate;";
 
+// Update resource metadata
+// params: $1: resource_id
+//         $2: contentlength
+static const char *sql_update_resource = "update Resource set contentlength = $2, lastmodified = now() where resource_id = $1;";
+
 VFS* pg_vfs_create(Session *sn, Request *rq, pblock *pb) {
     // resourcepool is required
     char *resource_pool = pblock_findval("resourcepool", pb);
@@ -455,6 +460,28 @@
     return ret;
 }
 
+int pg_update_resource(PgVFS *pg, int64_t resource_id, int64_t contentlength) {
+    char resid_str[32];
+    char ctlen_str[32];
+    snprintf(resid_str, 32, "%" PRId64, resource_id);
+    snprintf(ctlen_str, 32, "%" PRId64, contentlength);
+    
+    const char* params[2] = { resid_str, ctlen_str };
+    PGresult *result = PQexecParams(
+            pg->connection,
+            sql_update_resource,
+            2,     // number of parameters
+            NULL,
+            params, // parameter value
+            NULL,
+            NULL,
+            0);    // 0: result in text format
+    
+    int ret = PQresultStatus(result) == PGRES_COMMAND_OK ? 0 : 1;
+    PQclear(result);
+    return ret;
+}
+
 /* -------------------------- VFS functions -------------------------- */
 
 SYS_FILE pg_vfs_open(VFSContext *ctx, const char *path, int oflags) {
@@ -509,6 +536,7 @@
     pgfile->parent_id = parent_id;
     pgfile->oid = oid;
     pgfile->fd = fd;
+    pgfile->oflags = oflags;
     pgfile->s = s;
     
     file->ctx = ctx;
@@ -648,9 +676,18 @@
 
 void pg_vfs_io_close(SYS_FILE fd) {
     pool_handle_t *pool = fd->ctx->pool;
+    PgVFS *pgvfs = fd->ctx->vfs->instance;
     PgFile *pg = fd->data;
     
     if(pg->fd >= 0) {
+        if((pg->oflags & (O_WRONLY|O_RDWR)) > 0) {
+            // file modified, update length and lastmodified
+            off_t len = pg_vfs_io_seek(fd, 0, SEEK_END);
+            if(len < 0) len = 0;
+            
+            pg_update_resource(pgvfs, pg->resource_id, len);
+        }
+        
         PgVFS *pgvfs = fd->ctx->vfs->instance;
         lo_close(pgvfs->connection, pg->fd);
     }