Generating compressed column slabs for storage in a database system

A method comprising:

• determining a query having query predicates indicating a first column compressed as compressed column slabs in a set of segments;
• for each segment of the set of segments, determining row data for rows satisfying the query predicates by processing a corresponding compressed column slab of the each segment corresponding to the first column based on:
• determining a set of rows of the each segment for access;
• identifying ones of a set of variable-length compression frames of the compressed column slab written for the first column that include ones of the set of rows based on accessing a lookup structure corresponding to the corresponding compressed column slab;
• and
• generating the row data based on reading only the ones of the set of variable-length compression frames identified to include the ones of the set of rows, where the row data is generated based on a compression dictionary corresponding to the compressed column slab;
• and
• generating a query resultant for the query based on processing the row data for all segments of the set of segments.

A database system includes:

• at least one processor;
• and
• at least one memory that stores operational instructions that, when executed by the at least one processor, causes the database system to:
• determine a dataset for storage that includes, for each of a plurality of rows of the dataset, a plurality of column values corresponding to a plurality of columns of the dataset;
• generate a plurality of column slab data from the dataset, wherein each of the plurality of column slab data includes column values for one of the plurality of columns from a proper subset of rows of the plurality of rows assigned to one of a plurality of segments;
• train each of a plurality of compression dictionaries from a corresponding one of the plurality of column slab data;
• and
• generate each segment of the plurality of segments based on writing a set of compressed column slabs to the each segment based on compressing each of a corresponding set of the plurality of column slab data as a set of variable-length compression frames written to the each segment based on applying a corresponding one of the plurality of compression dictionaries.