Abstract: Methods for rowgroup consolidation with delta accumulation and versioning in distributed systems are performed. The systems provide performant methods of row storage that enable versioned modifications of data while keeping and allowing access to older versions of the data for point-in-time transactions. The accumulation of valid rows, deletes, and modifications is maintained in blobs for rowgroups until a size threshold is reached, at which point the rows are moved into a columnar compressed form. Changes to data and associated metadata are stored locally and globally via appends, maintaining logical consistency. Metadata is stored in footers of files allowing faster access to the metadata and its associated data for transactions and instant rollback via metadata version flipping for aborted transactions, as well as lock-free reads of data.

Abstract: Methods for rowgroup consolidation with delta accumulation and versioning in distributed systems are performed. The systems provide performant methods of row storage that enable versioned modifications of data while keeping and allowing access to older versions of the data for point-in-time transactions. The accumulation of valid rows, deletes, and modifications is maintained in blobs for rowgroups until a size threshold is reached, at which point the rows are moved into a columnar compressed form. Changes to data and associated metadata are stored locally and globally via appends, maintaining logical consistency. Metadata is stored in footers of files allowing faster access to the metadata and its associated data for transactions and instant rollback via metadata version flipping for aborted transactions, as well as lock-free reads of data.