Function to take a large object size:
<?php
function pg_lo_size ($lo) {
  $pos = pg_lo_tell ($lo);
  pg_lo_seek ($lo, 0, PGSQL_SEEK_END);
  $size = pg_lo_tell ($lo);
  pg_lo_seek ($lo, $pos, PGSQL_SEEK_SET);
  return $size;
}
?>(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
pg_lo_tell — 返回当前大型对象的指针位置
当前查找距离大对象开头的偏移量(字节数)。如果有错误,返回值为负。
示例 #1 pg_lo_tell() 示例
<?php
   $doc_oid = 189762345;
   $database = pg_connect("dbname=jacarta");
   pg_query($database, "begin");
   $handle = pg_lo_open($database, $doc_oid, "r");
   // 忽略开始的 50000 字节
   pg_lo_seek($handle, 50000, PGSQL_SEEK_SET);
   // 查看忽略了多少
   $offset = pg_lo_tell($handle);
   echo "Seek position is: $offset";
   pg_query($database, "commit");
?>以上示例会输出:
Seek position is: 50000
