5.1.6. Oracle Redo Reader Tuning
The VMware Redo Reader extracts information from the Oracle Redo logs and
places that information into an internal PLOG format. This contains the
raw transactional data. Unlike the Transaction History Log (THL) used by
Tungsten Replicator, the format of this information is not fully serialized.
The serialization process is performed by the Tungsten Replicator while the
data is being translated into the THL format.
The PLOG information is stored within the Tungsten Replicator installation
directory, within a directory named after the corresponding service. For
example, for the service alpha, the data is located in the
plog/alpha/mine/ directory. The
log information in these files is automatically rotated and managed in the
same manner as the THL files.
When processing very large transactions, for example when doing a bulk
load or extraction, the information is temporarily serialized to disk.
This can introduce additional disk space requirements when incorporating
these large transactions into the THL.