FAQs

Q1: What is NCR's 64-bit MPP Server Update?

A1: As you know, Teradata's roadmap is dependent on Intel's roadmap for server-class nodes. We planned to announce 64-bit MPP servers as early as the end of this year. However, the current 64-bit server nodes from Intel haven't achieved performance parity with the 32-bit nodes. Based on market predictions from industry analysts, including Gartner and IDC, we expect the performance difference to continue through 2006. The Teradata Database software is ready and is currently available on non-NCR Intel 64-bit SMP systems. Teradata Database is positioned to deliver on 64-bit MPP servers when they reach comparable performance levels to the 32-bit Intel servers. When that happens, Teradata will provide 32-bit customers with investment protection options for their current systems.

Q2: What is difference between perm space and spool space?

A2: The difference between perm space and spool space is that perm space is allocated to the database and will not share with other databases, while spool space is a reserved space that is shared by different users and, within the users' queries, is used to format the result sets.

Q3: I am using the Teradata JDBC type 4 driver. What port number does the driver use to talk to the database?

A3: With the type 4 driver it is not necessary to specify a port in the connection string since a gateway is not used. The type 4 driver communicates directly with Teradata, which uses port 1025.

Example: "server" is the name of the system where Teradata is running
String url4 = "jdbc:teradata://server";
con=DriverManager.getConnection (url4,"uid","password");

Q4: We have a DDL for our database layout. Currently, we have a column definition as follows:

activity_dt DATE NOT NULL FORMAT 'mm/dd/yyyy' DEFAULT -18989899,
The programmer ensured us that the default date would be 01/01/0001. But it is not; the UNIX timestamp above gives a date in 1969.

What is the syntax to define 01/01/0001 as the default date?

A4: Your programmer is right. The date field in Teradata is not a UNIX timestamp, but a different scheme altogether. The default shown above is correct, but for the best solution, use an ANSI date literal, as shown below.

activity_dt DATE NOT NULL FORMAT 'mm/dd/yyyy' DEFAULT DATE '0001-01-01'

Q5: We are just starting to work on Teradata and we have a question about building views. Do you know of a tool that could help us build dimensional views over third normal form models? We want these to be linked to the physical but still be independent, to inherit definitions but be modifiable, and to be documented (i.e. catalogued).

A5: If I read this correctly, you're saying that you have a normalized model and want to generate dimensional views to sit on top of it. You can do that by following the guidelines on how to develop views in the documentation.

Q6: Currently, there is no way to cancel a rollback. The rollback will survive a TPARESET. However, the GSC can stop it with a utility (I believe a chargeable event). They will perform a TPARESET to cap the new entries to the TJ, then stop the journaling by using the utility. You will lose all data in the transient journal, not just your particular rollback. All tables involved in the transient journaling will be in an invalid state and will either need to be dropped/recreated or restored. Is there a fix for this?

A6: There will be a new command in V2R5.1 Recovery Manager that will take care of this. It is: CANCEL ROLLBACK ON TABLE.

Q7: Suppose that incoming data targeted for an enterprise data warehouse is in various "character sets," i.e. kanji, Latin, etc. We would like to store the data in a consistent character set, but when the info is presented back to the client, we want to place it in the appropriate character set for that client.

Is there a "super type" character set that would allow for conversion to/from any character set? UNICODE seems close but still has exceptions. Is there a method to dynamically '.set session charset' if we were to present data from a method other than BTEQ?

A7: UNICODE is the "super type" server character set that Teradata offers. If it doesn't meet your specific need, then you would need to submit a request for change. We do offer some capability to customize conversions from client character sets to internal character sets, and this may address the exceptions that you mention. However, without specifics on the exceptions, it is unclear if there are solutions to this issue using current capabilities.

KANJISJIS might be another possibility to use as the server character set, but I suspect that would be less suitable than UNICODE. You can define the character column to be UNICODE or LATIN (you can also choose GRAPHIC, KANJI1 and KANJISJIS, but we encourage users to choose either UNICODE or LATIN).

e.g., create table test (col1 char(5) character set latin,
col2 char(5) character set unicode);

Incoming data will be translated internally to the form specified in the column definition. Outgoing data will be translated to the character-encoding scheme specified by the user (session character set). Users can change their character set without logging off, i.e. the session character set can be changed during a session.

I think most Teradata interfaces, including BTEQ and CLIv2, support a way to set the session's client character set. However, this must be done before logon (of course, one could log off, change setting and log back on when a change is necessary). I am not an ODBC/JDBC expert, but I assume they would have this capability also. The client character set cannot be changed during a session. The default server character set can be changed using the MODIFY USER statement; it can also be overridden for a column by explicitly specifying the CHARACTER SET after the character type.

Archived FAQs