Submitted by: @aafemt

Consider this code in after insert or update trigger on permanent table:
BEGIN
INSERT INTO temp_table (blob_field) VALUES (new.blob_filed);
END
Currently copy of BLOB's content is created in permanent storage, decreasing effectiveness of the operation and blowing DB file. Besides, on commit or disconnect this new copy of the BLOB is cleaned out, slowing down the process even more.
With BLOB content in the same temp space as the temp table, there is no need to run ordinary garbage collection process with records analysing and BLOBs erasing, it is enough to drop whole temp file.