Memory-Only Tables

Memory-only tables are not persisted by default like a regular table. You can add, modify, or delete records in a memory-only table.

A memory-only table name must adhere to the standard naming criteria. Each memory-only table exists within a schema and follows the standard name resolution rules for persisted tables.

The following scenarios/endpoints will create a memory-only table (unless persistence is specified):


  • Ingestion speed is better than persisted tables, as there are no disk writes.
  • There's no reliance on lookups between connected join data sets or scanning mask on filtered data sets, resulting in faster queries.
  • All memory-only tables created by endpoints copy data from their source data sets, thus their memory footprint can be quite large compared to a join view or a filtered view.

Limitations and Cautions

  • Primary Key fields contained within memory-only tables cannot be updated.
  • Object ID cannot be used to update or delete records.
  • Memory-only tables cannot contain store-only or non-charN string column types.
  • A memory-only table is not persisted, by default, and will not survive a database restart, though each endpoint that creates a memory-only table has an option to persist the table instead.
  • Memory-only tables can be evicted to disk cache if RAM is limited, thus incurring disk writes
  • Individual memory-only table types have additional limitations and properties that may differ from the preceding limitations. More information can be found in Aggregation, Except, Intersect, Projections, and Union.