Ticket #431 (closed defect: fixed)
Read-only tx per query on cluster defeats cache
|Reported by:||thompsonbry||Owned by:||thompsonbry|
As documented at , there is a major performance hit associated with the use of a read-only tx per query on the cluster. The problem is not the overhead of the interaction with the transaction manager. It is that the distinct transaction identifiers defeat the cache mechanisms in the data service, all of which are based on the long time stamp associated with the request. The problem is that the various tx ids assigned for queries all read from the same commit point, but they are never the less distinct values and hence the cache entries are not reused.
This issue exists to document the problem as it pertains to query and its resolution via the proposed workaround. See  for the long term fix for this and related cache problems. A workaround for this issue is also described at .
 https://sourceforge.net/apps/trac/bigdata/ticket/266 (Refactor native long tx id to thin object.)