Most Recent TeraData TDVAN5 Exam Dumps

In the given CREATE USER statement, the SKEW = 10 PERCENT parameter applies to Perm space and allows some AMPs (Access Module Processors) to use up to 10% more space than the average allocation across the AMPs.

The user is allocated 100 GB of Perm space across a 10-AMP system, meaning the average space per AMP is 10 GB.

With a 10% skew allowed, this means that an AMP can use up to 10% more than the average allocation, which is 10 GB + 1 GB = 11 GB.

IO SKEW refers to an uneven distribution of I/O operations across AMPs, which can occur during large redistributions or full table scans, as data needs to be read from or written to the entire table. High IO skew indicates that some AMPs are handling significantly more I/O than others, which is often a sign of inefficient data distribution or full table scanning.

QRY_B has an IO SKEW value of 2.76, which is much higher than the other queries, suggesting that it is likely performing a full table scan or large redistribution, as this would result in uneven I/O across AMPs.

CPU SKEW (as seen in QRY_D) could indicate an issue with CPU load balancing, but it doesn't necessarily suggest a full table scan or redistribution.

UII (Utility Impact Index) and PJI (Product Join Index) are also metrics that might indicate query inefficiencies, but the high IO SKEW in QRY_B is the most direct indicator of a full table scan or large redistribution.

QRY_B is the query suspected of causing the full table scan or large redistribution due to its high IO SKEW value.

The Lock Display portlet in Teradata Viewpoint provides detailed information about database locks. It allows the Administrator to monitor if any queries or jobs are causing lock contention that could block the critical job. Using this portlet, the Administrator can see if the development jobs are creating locks that delay or block the critical job. If such blocking is detected, the Administrator can take action, such as aborting the development jobs.

Option A (Query Session) shows information about active sessions but is not focused on lock contention and blocking.

Option B (Query Monitor) allows the monitoring of query performance and workloads but doesn't specifically focus on lock contention.

Option C (Show Locks) can display current lock information, but Lock Display provides a more comprehensive tool for monitoring and managing lock-related issues.

Merge step issues often occur when a large amount of data is being processed during the table creation, especially if the system is trying to simultaneously create the table and insert data.

By using 'WITH NO DATA', the table structure is created first, without the actual data being inserted during the table creation process. The *'INSERT ... SELECT ' command can then be used afterwards to populate the table in a more controlled way, reducing the load on the system during the creation phase and potentially improving the efficiency of the merge step.

Specifying a good distribution for the primary index can help overall performance, but it doesn't directly address the issue with the merge step in this scenario.

Specifying the MERGEBLOCKRATIO isn't typically a solution for this specific problem; the merge block ratio is more about the optimization of data block merges rather than the creation of tables.

Moving the creation to off-peak hours may help if the environment is busy, but it doesn't directly address the core issue of the merge step getting stuck.

The OBJECTS option in DBQL (Database Query Logging) records the tables and other objects that are accessed by queries, including information on how many rows are added, updated, or deleted. This allows the capacity planner to track changes to specific tables without modifying the application itself.

The other options are less relevant to tracking row changes:

USECOUNT records how often specific queries are executed, but not the number of rows affected.

EXPLAIN captures the query execution plan, which doesn't provide details on rows added or deleted.

VERBOSE XMLPLAN gives detailed execution plans in XML format, but it is more focused on query execution and optimization, not tracking row modifications.