Snowflake Inc.
Incremental clustering maintenance of a table

Abstract:

A method includes storing table data for a table in a plurality of partitions and for maintaining approximate or good enough clustering. The method includes creating one or more new partitions based on changes to the table, wherein at least one of the one or more new partitions overlap with each other or previous partitions resulting in a decrease in a degree of clustering of the table. The method includes determining that a degree of clustering of the table data is below a clustering threshold. The method further includes reclustering one or more partitions of the table to improve the degree of clustering of the table in response to one or more of: determining that the degree of clustering has fallen below the clustering threshold, an explicit user command from a user, and/or as part of a DML command. Reclustering may be performed in incremental steps to iteratively improve clustering.