Exalytics - Timesten Configuration

at the Kernel Level

You can configure and activate the number of large pages by setting the nr_hugepages parameter in the /etc/sysctl.conf file. For an 800GB TimesTen database, you must specify greater than 410122 pages to create an 800GB store based on the following calculation (All in Byte):

(400*1024*1024*1024) + (400*1024*1024*1024) + (1024*1024*1024) + (20*1024*1024) = 860088172544

860088172544 / (2 * 1024 * 1024) = 410122

For example, to allow for spare capacity, modify the following setting in the /etc/sysctl.conf file:

vm.nr_hugepages = 410200

then either restart the machine or run the following command as the root user:

/sbin/sysctl –p

for TimesTen Databases

You can configure large pages for the TimesTen database by editing the following file:

/home/oracle/TimesTen/tt1122/info/ttendaemon.options

and adding the following line:

-linuxLargePageAlignment 2

Configuration

The TimesTen In-Memory Databases are defined using a DSN that is contained in the sys.odbc.ini file in the following directory:

/home/oracle/TimesTen/tt1122/info

Sample file on an Exalytics Machine of a TimesTen instance that is used for aggregate storage:

[ODBC Data Sources]
TT_AGGR_STORE=TimesTen 11.2.2 Driver
 
[TT_AGGR_STORE]
Driver=/home/oracle/TimesTen/tt1122/lib/libtten.so
DataStore=/home/oracle/aggregate_store/tt_aggr_store
LogDir=/home/oracle/aggregate_store/logs
DatabaseCharacterSet=AL32UTF8
ConnectionCharacterSet=AL32UTF8
LogFileSize=1024 
LogBufMB=1024 
LogBufParallelism=16
Preallocate=0 
PermSize=25000 
TempSize=25000 
MemoryLock=4 
CkptFrequency=30 
CkptLogVolume=0 
CkptRate=20 
PrivateCommands=1 
RecoveryThreads=40

This DSN supports a TimesTen In-Memory Database of 25GB with overall memory consumption of approximately 50GB.

To support larger in-memory data stores, increase the settings of the PermSize and TempSize parameters.

To support this DSN definition, the semi-automated installation process creates the following directories on the Exalytics Machine:

/home/oracle/aggregate_store
/home/oracle/aggregate_store/logs

Instantiation

The TimesTen In-Memory Database is instantiated when the first connection is made to the database.

cd /home/oracle/TimesTen/tt1122/bin
./ttIsql
connect dsn=TT_AGGR_STORE;
create user exalytics identified by welcome1;
grant create session to exalytics;
grant create table to exalytics;
grant select on SYS.OBJ$ to exalytics;

Use the following sample commands to test the connection to the TimesTen In-Memory Database. There are no tables of data yet configured to return.

connect "DSN=TT_AGGR_STORE;uid=exalytics";
tables;
exit

Physical Layer

When mapping a TimesTen source into the Physical layer of the Oracle BI repository, ensure that:

• the database type and version are set correctly in the Database field of the General tab of the Database dialog.
• the Call interface field in the General tab of the Connection Pool dialog is set correctly. For TimesTen version 11.2.2., use the ODBC 3.5 call interface.