Known issues

APPLY_SVD and APPLY_PCA functions are implemented as User-Defined Transform Functions (UDTFs). A query containing a UDTF that takes many input columns (e.g. more than 1000) and also outputs many columns may fail with error "Request size too big" due to additional memory requirement in parsing.

Workaround: Increase configuration parameter MaxParsedQuerySizeMB or reduce the number of output columns. For the cases of APPLY_SVD and APPLY_PCA, you can limit the number of output columns either by setting the parameter num_components or by setting the parameter cutoff. In practice, cutoff=0.9 is usually enough.

Please note that If you increase MaxParsedQuerySizeMB to a larger value, for example 4096, each query you run may use 4 GB of memory during parsing. This means running multiple queries at the same time could cause out-of-memory (OOM) if your total memory is limited. Please refer to Vertica documentation for more information about MaxParsedQuerySizeMB.

In very rare circumstances, if a Vertica process crashes during shutdown, the remaining processes might hang indefinitely.

Workaround: Halt the remaining processes using admin tools.

Under special circumstances, a sequence of statements to create and drop Python libraries fails. For example, the following session statements attempt to create Python libraries lib1 and lib2:

CREATE LIBRARY lib1 AS :lib1_path DEPENDS :numpy_path LANGUAGE 'Python'; DROP LIBRARY lib1; CREATE LIBRARY lib2 AS :lib2_path DEPENDS :sklearn_path LANGUAGE 'Python';

Here, lib1 is a Python library that imports module numpy, while lib2 imports module sklearn, which relies on numpy. After lib1 is dropped, the CREATE LIBRARY statement for lib2 fails. Workaround: One of the following:

• In the same session, repeat the CREATE LIBRARY statement for the second library.
• Start another session and create the second library.
• Add the following lines of code to the second library's Python script before importing its module:

  import importlib
  importlib.reload(<library-1-module>)
  # e.g. importlib.reload(numpy)
  

A vbr restore operation can fail if your database is configured for SSL and has a server.key and a server.crt file present in the catalog directory.

Workaround: Move your SSL authentication related files (server.crt, server.csr and server.key) from the catalog directory before performing the restore.

Creating a load balance group for a subcluster with a ROUNDROBIN load balance policy only has an effect if you set the global load balancing policy to ROUNDROBIN as well. This is the case, even though the LOAD_BALANCE_GROUPS system table shows the group's policy as ROUNDROBIN.

Workaround: Set the global load balancing policy using the SET_LOAD_BALANCE_POLICY function: SELECT set_load_balance_policy('roundrobin');

When quickly stopping and then starting a different database, the new database may fail to start after attempting to connect to Spread processes associated with the stopped database.

Workaround: After stopping a database, ensure that all old Spread processes have stopped on the affected nodes before starting a different database. This typically takes no more than one minute, but may vary under certain circumstances.

Under special circumstances, a sequence of statements to create and drop Python libraries fails. For example, the following session statements attempt to create Python libraries lib1 and lib2:

CREATE LIBRARY lib1 AS :lib1_path DEPENDS :numpy_path LANGUAGE 'Python';
DROP LIBRARY lib1;
CREATE LIBRARY lib2 AS :lib2_path DEPENDS :sklearn_path LANGUAGE 'Python';

Here, lib1 is a Python library that imports module numpy, while lib2 imports module sklearn, which relies on numpy. After lib1 is dropped, the CREATE LIBRARY statement for lib2 fails.