Limitations

Kinetica has some limitations for any columns marked as store-only and string columns lacking a charN attribute.


Unlimited-Width Strings

String columns with no charN attribute are stored in whole on disk and in hashed form in memory. Because the strings are only available for processing as hashes, only equality-based operations can be applied to them.

Partially Applicable Operations

  • Scalar Column Functions
    • Null Functions (except ZEROIFNULL )
    • Conditional Functions (equality-based)
  • Aggregate Column Functions
    • COUNT
    • COUNT DISTINCT
  • WHERE (predicate condition must be equality-based)
  • JOIN (join condition must be equality-based)

Inapplicable Operations

  • Subqueries requiring a temporary view to be created
  • GROUP BY
  • UNION
  • INTERSECT
  • EXCEPT
  • CREATE TABLE ... AS

Store-Only Columns

Columns marked store-only are only stored on disk, not in memory. Because they are not available for processing, only data extraction operations can be applied to them.

Inapplicable Operations

  • Scalar or Aggregate Column Functions
  • Subqueries requiring a temporary view to be created
  • WHERE
  • GROUP BY
  • JOIN
  • UNION
  • INTERSECT
  • EXCEPT
  • CREATE TABLE ... AS

Correlated Subqueries

Correlated subqueries have the following limitations:

  • They cannot reference grouping columns in the parent query
  • They cannot reference tables beyond the immediate outer query; i.e., a table cannot be referenced in a correlated subquery that is two or more levels of nesting deeper than it is
  • They cannot contain disjunctive conditions
  • They cannot be part of an OUTER JOIN ON clause condition

Not Yet Supported SQL

  • Windowing Features
    • Frame Exclusion (EXCLUDE)
  • Ranking Functions
    • PERCENTILE_DISC
    • PERCENTILE_CONT
  • Writing CSV files