db-ojb-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Oleg Nitz ...@ukr.net>
Subject default isolation level
Date Sun, 22 Dec 2002 17:03:33 GMT
Hi All,

I've noticed that OJB seems to use READ_UNCOMMITTED isolation level by 
default. But
1) AFAIK with READ_COMMITTED isolation level database server works much 
faster, at least this is true for Sybase ASE. I suppose that for 
READ_UNCOMMITTED level table indices can't be used at all because they are 
updated on commit, so any query on uncommitted data requires full table 
scans, for queries with joins on big tables the difference of execution time 
with READ_COMMITTED and with READ_UNCOMMITTED is amazing.
2) I haven't found any setTransactionIsolation() calls in OJB code, so I 
suppose that isolation-level attribute in repository.xml is simply ignored 
now, OJB works always in READ_COMMITTED mode, which is good for performance 

So I propose to fix 2) and to set level to READ_COMMITTED by default.
I could do this.


View raw message