HANA Flashcards
(51 cards)
Where can you check if hardware on a customer’s HANA system is supported?
Check the HANA hardware directory
If I upgraded my HANA database from revision 125.10 to 125.35, what kind of release would I call 125.35?
Maintenance Revision
What happens if a customer uses more memory than their license allows?
Depends on type of license (temp/perm, enforced/unenforced)
What does the sapstartsrv service do?
1) Starts the Daemon.
2) Collects the log files and trace files if the database crashes.
If the global allocation limit for memory is nearly at capacity, and we then see a large memory request that would exceed the limit, what would happen
1) Out of memory dumps (OOM) would occur.
2) HANA will unload tables and columns from the main memory to make space.
What are savepoints and what are they used for?
1) Used to recover the database to a consistent state without needing redo logs.
2) A savepoint is overwritten when the next savepoint is successfully completed.
3) They can be used to speed up a restart of HANA DB.
If a transaction causes a commit statement that inserts millions of new records into a column store table and then an Auto-Merge occurs on this table, what does this sequence of events look like?
1) A savepoint occurs and HANA flushes all the changed data from memory to the data volume.
2) During the write operation, log entries are written to the log buffer in memory.
3) During the commit, log entries are flushed to disk synchronously.
If you update a record in a row store table using SQL in the SQL editor in HANA studio and the Auto Commit feature is turned ON, which component does this write operation occur in for MVCC?
Transactional Version Memory (Write operations create new versions in TVM, visible version then moved from TVM to persisted segment based on commit ID)
What is the best way to partition a table over 3 different worker nodes that breaks the table into 3 ranges. For example year 2019 - 2020, 2021 - 2022, 2022 - 2023?
Partition the table with multi-level partitioning using HASH at the end of the 1st level for load balancing and RANGE at the 2nd level for time based partitioning
In a scale out system with 1 master node and 2 worker nodes and 1 standby node, how many index servers are there?
1 master and the 2 workers index servers are active.
If a customer wants to migrate their BW system to an on-premise HANA solution, but have a low budget, what should they do to reduce costs and use their existing software instead?
Tailored Datacenter Integration (TDI)
What types of compression are used in HANA?
Clustered
Prefixed
Indirect
The different services startup in specific sequences. What is the name of the process that decides this sequence?
Runlevel
When checking the table definition for a distributed table in a scale out system, and select the Runtime Information tab in HANA studio, what can we see?
1) Partition specification.
2) Number of partitions.
3) Delta size for column store tables.
How do you check if there are indexes on a table or for the data in the table?
1) In the table definition tab.
2) In the table content tab.
If you check the expensive statements list in HANA studio and find that there is no information, why might this be?
The expensive statements trace is not turned on.
What are the prerequisites to access HANA cockpit?
1) The web browser must support SAPUI5.
2) If your HANA database is on SPS10 or higher you can logon as the SYSTEM user.
3) The DB user needs to be assigned the sap.hana.admin.roles::monitoring or sap.hana.admin.roles::administrator roles
What can you see in the catalog folder in HANA studio?
Tables, Views and Stored Procedures.
A HANA DB is receiving many low priority alerts related to the number of records in column store tables. There are no obvious reasons for these alerts. What would be the next logical thing to do?
You increase the thresholds for the occurrence of this type of alert to more meaningful value
How do you collect runtime environment dumps on HANA DB?
Configure the collection of diagnostic information in the diagnostic files tab of HANA studio.
What is the best way to analyse a poorly performing SQL statement with 1000s of evictions per hour?
Check if bind values are used in the WHERE clause of the statement
If you want to capture all SQL statements that exceed a defined threshold, what kind of trace would you switch on for HANA?
Expensive statement trace.
If the global statement memory limit is 100 GB and the user statement memory limit is 200 GB, and a user wants to execute a report that will consume 150 GB, what will happen?
The report will run successfully as the user statement limit takes priority over global statement memory limit
If the statement memory limit on HANA DB is set to 100 GB, and you sometimes see queries are terminating even though there is low overall memory usage, how would you allow a statement to continue when overall memory usage is below a certain percentage?
Activate parameter statement_memory_limit_threshold
