Unexpected SQL crash when using timestamp function on empty table

[Jyotigarg1407]

To reproduce

1. Go to QuestDB Web Console or connect via REST API
2. Create an empty table:
   CREATE TABLE test_empty (ts TIMESTAMP);
3. Run the following SQL query:
   SELECT timestamp(ts) FROM test_empty;
4. Observe the crash or error message

QuestDB version:

7.3.5

OS, in case of Docker specify Docker and the Host OS:

Docker on Ubuntu 22.04

File System, in case of Docker specify Host File System:

ext4

Full Name:

Jyoti Agrawal

Affiliation:

Oracle

Have you followed Linux, MacOs kernel configuration steps to increase Maximum open files and Maximum virtual memory areas limit?

• Yes, I have

Additional context

Crash only occurs on empty tables when calling timestamp()

This may be related to internal null handling

Example log output:
[questdb] [ERROR] java.lang.NullPointerException at ...

[kafka1991]

Hi @Jyotigarg1407

• timestamp(ts) is not a function and should not appear in the projection (select list); it is actually used to specify the timestamp column for a table or subquery
• The NPE exception has been resolved in the latest version, You could consider upgrading.