How can I measure the amount of space taken by blobs on a Firebird 2.1 database?

Question

I have a production database, using Firebird 2.1, where I need to find out how much space is used by each table, including the blobs. The blob-part is the tricky one, because it is not covered using the standard statistical report.

I do not have easy access to the server's desktop, so installing UDFs etc. is not a good solution.

How can I do this easily?

Answer 1

You can count total size of all BLOB fields in a database with following statement:

EXECUTE BLOCK RETURNS (BLOB_SIZE BIGINT)
AS
  DECLARE VARIABLE RN CHAR(31) CHARACTER SET UNICODE_FSS;
  DECLARE VARIABLE FN CHAR(31) CHARACTER SET UNICODE_FSS;
  DECLARE VARIABLE S BIGINT;
BEGIN
  BLOB_SIZE = 0;
  FOR
    SELECT r.rdb$relation_name, r.rdb$field_name 
      FROM rdb$relation_fields r JOIN rdb$fields f 
        ON r.rdb$field_source = f.rdb$field_name
    WHERE f.rdb$field_type = 261
    INTO :RN, :FN
  DO BEGIN
    EXECUTE STATEMENT
      'SELECT SUM(OCTET_LENGTH(' || :FN || ')) FROM ' || :RN ||
      ' WHERE NOT ' || :FN || ' IS NULL'
    INTO :S;
    BLOB_SIZE = :BLOB_SIZE + COALESCE(:S, 0);
  END
  SUSPEND;
END