Database Objects: Catalog, Views, Procedures & Functions

You declare a HANA column as FLOAT(n) expecting single-precision storage. At what value of n does HANA silently give you DOUBLE instead of REAL?

Why is VARCHAR the wrong choice for a column that may hold ABAP CHAR data or any non-English text in HANA?

A HANA TIMESTAMP advertises FF7 (7 fractional-second digits, 100 ns). Can you rely on that to distinguish two events microseconds apart?

For a large free-text column that may contain non-English (Unicode) content, which LOB type is correct, and what breaks if you pick CLOB?

A user complains they still can't read a table after you created a public synonym for it. Is the synonym broken?

You need to compute a value inline within a SELECT's column list. Why must that be a function and not a stored procedure?

A client reads a HANA BOOLEAN column and gets 1s and 0s — and some NULLs you didn't expect. What's going on?

You reflexively type DESCRIBE on a HANA table and it fails. What do you query instead to see the table and its columns in order?

Why does the column store cut I/O most dramatically for OLAP queries with selection criteria, rather than benefiting all workloads equally?

An ALPHANUM(8) column stores '95' as '00000095' but 'SAP' unchanged. What rule produces this split behavior?

You need to silence one trigger during a bulk load without losing its code. What statement do you use, and where do you read the code back afterward?

An auditor requires invoice numbers that are gap-free and strictly in chronological commit order. Why is a HANA sequence the wrong tool?

Why can you query a system view by its bare name without prefixing SYS, and how would you confirm the mechanism?

A view must run unchanged if the system is later moved off HANA to another database. ABAP CDS or SAP HANA CDS — and what tool maintains it?

You plan a TINYINT column to store small values including occasional negatives. What's the trap?

Column-store INSERTs are slower than row-store. Why is the column store still the default choice for SAP HANA tables?

Why does a query against "myTable" fail when the object seems to exist, and what does SAP's use of '/' have to do with it?

In the VIEWS catalog, which single column reliably separates an SQL view from a column view, and why isn't VIEW_TYPE enough on its own?

You need to inspect where a HANA sequence currently stands without advancing it. Why is NEXTVAL the wrong way, and what do you read instead?

A SQL view is slow. Before assuming the view itself is the problem, what should you suspect first?

A WHERE clause using = NULL returns zero rows even though NULLs clearly exist. Why, and what's the correct test?

You want an INSERT on a view to silently redirect to other logic instead of actually inserting. Which trigger timing do you need, and why not BEFORE/AFTER?

You're auditing constraint enforcement in HANA. Why might you find foreign-key logic showing up as triggers rather than as indexes?

In OBJECT_DEPENDENCIES you see dependency values of 1 and 2. What do they mean before you act on an impact analysis?

If HANA holds everything in memory, when is it still worth creating an index, and on what kind of access pattern?

When a referenced key is updated and matching child rows exist, what does HANA do by DEFAULT — and what are the alternatives if you want updates to flow through?

Two objects with the same name exist in your current schema and in PUBLIC. Which one does an unqualified reference hit?

The VIEWS catalog shows IS_VALID='FALSE' for a view. What does that actually tell you about the cause and the fix?

To avoid a sequence ever exhausting, a colleague sets CYCLE. Why is that dangerous, and what's the default limit anyway?

Why does RESET BY on a sequence matter specifically after a restore or restart, and when does its query actually run?

What do you give up, and what do you gain, by declaring a procedure READS SQL DATA?

Why shouldn't you create column views by hand with CREATE COLUMN VIEW, and where do the proper ones end up?

Right after you CREATE a HANA user, where do objects they create land — and what makes them the owner?

In which kinds of SQL statements can a HANA user-defined function (UDF) actually be used — beyond plain SELECT?

Another session asks you for the 'current' sequence value via CURRVAL and gets a 'can't find currval location' error. Why?

You drop a table that several views reference. Are those views gone, and what happens when you recreate the table?

On a multinode HANA system, sequence numbers show gaps even with no failed transactions. Bug or expected?

When does a plain CREATE SYNONYM fall short, so you need CREATE PUBLIC SYNONYM instead?

Besides SQLScript, which two languages can a HANA stored procedure be written in, and how is the language selected?

You name an object with a hyphen or dot and references start failing unless quoted. What rule did you hit?

When is SECONDDATE the better choice than TIMESTAMP for a date-time column?

What is the SAP HANA database catalog, and how do applications read its metadata?

Why is a HANA ARRAY a poor fit for a value list you'll append to, or for storing a few documents?

A migration team wants to drop 'unnecessary' indexes in HANA because it's in-memory. Which index role can they NOT safely drop?

A procedure must read tables the calling user has no direct grant on. Should SQL SECURITY be DEFINER or INVOKER, and what's the risk of the other choice?