Hi All,

I have a log table that records all updates/inserts/deletes
from several tables. (using triggers)

It does so by registering :
SEQ_NR Integer,
TABLE_NAME Varchar(100),
TRANTYPE Varchar(1),
UPDDATE Timestamp,
OBJECT_SEQ_NR Varchar(100),
REPL_STATUS Varchar(1),
ERROR_CODE Varchar(100),
ERROR_MSG Varchar(255),

normally this works fine (up to ~ 70 million records) when suddenly it started to take a lot of time (from 20 ms to 900ms maybe higher)

My theory ,the main reason why this got slow has to do with the total index size of this table that must be maintained in RAM.

There are indexes on seq_nr ,table_name, object_seq_nr this give me at least 260 index bytes per record (according to index calc. Ivan Prenosil ).

This totals up to (260*70.000.000)/1024/1000= 17773 MB of RAM required (could be less because TABLE_NAME is not unique).

Question: Since the machine has only 16000 MB RAM. Could this be the bottleneck i hit on ?
(after a backup/restore it seems this problem disappears but i fear it will return again after being in production for a while)

(this is FB2.5/classic running on linux 64 bits)


Regards,
Derryck