What is Savepoint in SAP HANA?

What are some of the benefits of the SAP HANA data anonymization feature

Data anonymization

• Enables customers to utilize personal data without inferring the privacy of individuals.
• Makes analytics and machine learning scenarios of anonymized personal data possible.
• Enhances customer's ROI by leveraging the value of enterprise data that was previously inaccessible.

How do I change the log mode in Hana studio

We recommend that you use the SAP HANA Studio to perform the configuration changes.

1. Open the Administration Editor of the system and navigate to the "Configuration" tab.
2. Change the paths in which data backups and log backups are to be saved so that sufficient disk space is available.
3. Set the log mode to "normal".

How is Delta merge triggered in SAP HANA

Once the DataStore object (advanced) has been activated, an automatic check is run to see whether a delta merge can be performed. The data transfer process (DTP) has an Update tab that contains the Trigger Database Merge checkbox. This controls the delta merge, once the DTP request has been successfully processed.

How do I merge Delta in Hana studio

You can trigger the delta merge operation for a column table manually in the SAP HANA studio by menu command or SQL statement. A manually-executed delta merge operation corresponds to a hard merge. However, if you use SQL, you can also pass additional parameters that trigger forced merges and memory-only merges.

How do you do a Delta merge

Open the SQL console and execute the required statement: MERGE DELTA OF ' <table_name> ' (hard merge) MERGE DELTA OF ' <table_name> ' WITH PARAMETERS ('FORCED_MERGE' = 'ON') (forced merge)
Procedure

1. In the Systems view, navigate to the table.
2. In the context menu of the table, choose Perform Delta Merge.
3. Choose OK.

How is Delta merge triggered automatically

When a read access is executed, the data is read from the main storage and the delta storage and the results are merged together. The check and the delta merge – if data has been changed during Data Warehouse load processes – are either performed automatically by the system or must be triggered manually.

How do I find the last Delta merge in SAP HANA

You can access a predefined view of these merge statistics in the statement library of the SAP HANA database explorer.
The following values are possible:

1. MERGE for an actual delta merge operation.
2. HINT for a merge hint sent to SAP HANA by an application.
3. SPARSE for the post-merge optimization of main storage compression.

What is a savepoint in Hana

A savepoint ensures that all changed persistent data since the last savepoint gets written to disk. The SAP HANA database triggers savepoints in 5 minutes intervals by default. Data is automatically saved from memory to the data volume located on disk. Savepoints run asynchronously to SAP HANA update operations.

What are different compression techniques in Hana

Compression Techniques in SAP HANA

• Dictionary Compression. Dictionary compression is a standard compression method to reduce data volume in the main memory.
• Prefix Encoding Compression.
• Run-length Encoding Compression.
• Cluster Encoding Compression.
• Indirect Encoding Compression.
• Sparse Encoding Compression.

What is global allocation limit Hana

The global allocation limit is calculated by default as follows: > 64 Gb: 90% of the first 64 GB of available physical memory on the host plus 97% of each further GB . < 64 Gb: Physical memory minus 1 GB .

What is a characteristic of the synchronous in memory system replication mode in SAP HANA

In the synchronous mode of system replication, the primary node waits and halts its transactions till the time the secondary node sends an acknowledgment. The acknowledgment indicates the acceptance of the data log and persistence of the log volumes on its disk.

How does Delta merge work in SAP HANA

You can trigger the delta merge operation for a column table manually in the SAP HANA studio by menu command or SQL statement. A manually-executed delta merge operation corresponds to a hard merge. However, if you use SQL, you can also pass additional parameters that trigger forced merges and memory-only merges.

What is the difference between row store and column store

A row store stores a sequence of records that contains the fields of one row in the table. In a column store, the entries of a column are stored in contiguous memory locations.

What is column Store in Hana

In a column store, the entries of a column are stored in contiguous memory locations. Principle of Row- and Column-Based Storage for a Table. In the SAP HANA database, tables that are organized in columns are optimized for high-performing read operations while still providing good performance for write operations.

What is auto merge in SAP HANA

Auto merge is active if the active parameter in the mergedog section of the indexserver. ini file is set to yes. Note Auto merge can be activated and deactivated for an individual table in the system view TABLES (SYS). The value in the column AUTO_MERGE_ON can be changed to TRUE or FALSE.

How do I DECLARE variables in Hana

Sap hana local variables are declared either in the procedure header or in the procedure body. A variable is initially created using the DECLARE keyword followed with the variable name and data type. Values can either be initialized as part as the variable declaration or in the procedure body.

What is calculated column in SAP HANA

What is Calculated Column? Calculated columns in a SAP HANA database table can be considered as fields whose values are expressed as an output of a SQL expression which can use other column values and some other data as input parameters.

What are calculation views in SAP HANA

A calculation view is a flexible information view that you can use to define more advanced slices on the data available in the SAP HANA database. Calculation views are simple and yet powerful because they mirror the functionality found in both attribute views and analytic views, and also other analytic capabilities.