Knowledge quiz

It's time to put what you've learned to the test, get 8 right to pass this week.

How does the Optimize Join Columns setting relate to join pruning?

Choose the correct answer.

There is no relationship between Optimize Join Columns and join pruning.

The Optimize Join Columns setting is the prerequisite for join pruning.

Join pruning is the prerequisite for Optimize Join Columns to have an effect.

Optimize Join Columns is only related to the static cache and not to join pruning.

In which type of node can you set Optimize Join Columns?

Choose the correct answer.

Only in join nodes

Only in union nodes

In union and join nodes

In any type of node

What can happen if no join column is requested from a dynamic join by default?

Choose the correct answer.

This is the typical situation, and no problem will occur.

The join might fail if no preventive steps, such as setting a keep flag, have been taken.

Due to the nature of dynamic joins, the joins will be dissolved, and the node omitted.

The first join column will be taken as the only join column.

What does the hint RESULT_CACHE_BEFORE_ANALYTIC_PRIVILEGE do?

Choose the correct answer.

It tells SAP HANA to read from the static cache first, and then apply the analytic privilege.

It tells SAP HANA to add an analytic privilege to the static cache.

It tells SAP HANA to ignore the analytic privilege.

It tells SAP HANA to create a static cache entry for a specific analytic privilege.

How can you verify the impact of model changes based on recommendations from the model health check?

Choose the correct answer.

There are no options to verify the impact.

Check the execution plan of an individual query with SQL Analyzer from the SQL console.

The only option is to enable tracing and analyzing on the corresponding trace file.

If an individual query is executed from the SQL console, a warning will be raised if the applied changes have no impact.

What effect can the correct definition of the pruning criteria have on the results?

There are two correct answers.

The same data is always returned with and without column-based pruning.

The returned data can differ depending on whether column-based pruning is switched on or not.

The same data is always returned, independent of whether explicit or implicit pruning is defined.

Implicit pruning often delivers a subset of the data that is returned with explicit pruning because of its stricter criteria.

What is the relationship between explicit and implicit union pruning?

Choose the correct answer.

Explicit pruning is preferred over implicit pruning for performance reasons

Explicit union pruning offers a more flexible way to define the pruning criteria.

Explicit and implicit union pruning refer to the same mechanism and the query user decides which one to choose.

Explicit union pruning is the replacement in SAP HANA Cloud for implicit union pruning, which is used in on-premise systems.

In which situations does Optimize Join Columns reduce the number of processed columns?

Choose the correct answer.

In all joins, independent of whether join pruning occurs or not

If join pruning occurs and the join columns are requested by the query

If the join columns are not requested and join pruning takes place

If a union node above the join node projects fewer columns than the join node

What are some benefits of using a static cache?

There are three correct answers.

Results can be read from memory, increasing performance.

A subset of columns can be cached.

Filters can be pre-applied to cached results.

Cached and non-cached results can be mixed.

Static cache allows the use of hints.

10.

What is the minimum number of join conditions (columns) that need to be defined before you can set a Dynamic Join?”

Choose the correct answer.

There is no restriction and dynamic joins can be used with any number of join conditions.

To define a dynamic join, at least two join conditions need to be defined.

The only requirement is that the number of join conditions should be less than 10% of the number of columns.

The number of join conditions needs to be between 1 and 5.