TimesTen In-Memory Database
for Extreme Performance

Back to Basics - Multiple Connections in ttIsql

A user recently asked if ttIsql
can support multiple concurrent connections to a TimesTen database. We thought
the answer might be of interest to other users as well, and decided to include
it in this blog.

ttIsql is an interactive SQL command line utility for working
with TimesTen databases. In addition to supporting SQL command execution, ttIsql provides a rich set of
functionality to enable the users to connect to the databases, execute built-in
procedures and utilities, support flexible command editing, and the ability to
invoke host OS commands, all within the same ttIsql session.

One of the scenarios where it’s convenient to have multiple connections
within the same ttIsql session is
when you want to execute commands that require different user credentials.  For example, there are database operations
that require the Admin privilege, and other operations that only require table
owner or general database access privileges. 

If you plan to use multiple connections, it’s useful to name the
connections so that ttIsql can help you clearly identify which connection you
are executing. 

In the example below, we will create two connections to the sample
database, sampledb – first connection
as the application user (appuser) and
the second connection as the Admin user (adm). We will use the CONNECT command
and specify a connection name for each:

$ ttIsq

Command> CONNECT “DSN=sampledb;uid=appuser;pwd=appuser;ConnectionName=app_conn”;

Command> SELECT count (*) from mytable;

< 1000000 >
1 row found.

Command> CONNECT "DSN=sampledb; uid=adm;
pwd=adm; ConnectionName=adm_conn";

adm_conn: Command>

In ttIsql, the last
connection made is the current active connection, and the ttIsql prompt displays the connection name currently in use. As
shown above, adm_conn is the
connection currently in use.

adm_conn: Command> CALL ttRamPolicySet (‘manual’);

The ttRamPolicySet built-in procedure
requires the ADMIN privilege; instead of exiting the current ttIsql session or starting another
session, we conveniently use the multiple connection functionality here. As shown above, we executed a command to set
the RAM policy to MANUAL using the Admin connection.

To switch to a different connection, you simply execute the USE command:

adm_conn: Command> USE app_conn;

app_conn: Command> CALL ttVersion();

< 11, 2, 2, 8, 0 >
1 row found.

Notice that after the USE
command, the ttisql prompt changed to
the app_conn to indicate the current
connection context. ttVersion is a
built-in procedure that returns the current TimesTen version, and it can be
called by any user.

To disconnect a connection, use
the DISCONNECT command:

app_conn: Command> DISCONNECT

Another useful feature in ttIsql is the ability to execute host OS
commands. You can execute any OS commands that you are entitled to. As a simple
example below, we executed the MORE command to view the content in myconfig.ini file:

app_conn: Command> HOST more /home/appuser/myconfig.ini

This is myconfig.ini file
Line 1
Line 2
Line 3

app_conn: Command> exit


There are
many other features in ttIsql you can
use to help automate your day-to-day operations. Refer to the TimesTen
Database Reference
product documentation for more details.

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