keyedTable

swordfish.function.keyedTable()

Create an keyed table, which is a special type of in-memory table with primary key. The primary key can be one column or multiple columns. The keyed table is implemented based on a hash table, storing the combined value of the primary key fields as a key entry, with each key entry corresponding to a record in the table. During queries, by specifying all fields of the primary key, data can be located through the index without performing a full table scan. It is recommended to use sliceByKey to improve query performance.

When adding new records to the table, if the primary key of the new record duplicates an existing record, the system updates the record in the table; otherwise, the new record is added to the table.

Keyed tables exhibit better performance for single-record updates and queries, making them an ideal choice for data caching. Keyed tables can also serve as output tables for time series engines for real time updates.

Note

This function does not support creating a keyed table containing array vector columns.