Adaptive scan for hybrid tables

A method comprising:

• receiving a query, the query including at least one predicate for applying on a column of a table;
• performing a secondary index scan operation of a secondary index based on the query;
• adaptively determining, during execution of the secondary index scan operation, that a number of rows returned, from the secondary index scan operation, meets a threshold value, the threshold value comprising a cardinality of a particular set of values of a column of a table, and wherein the threshold value is determined by monitoring a count of rows returned during execution of the secondary index scan operation;
• in response to the number of rows meeting the threshold value, sending a signal to a primary index probe operation to initiate a blob storage scan using at least one range scan operation, wherein the signal triggers a runtime mode switch from index probe operations to range scan operations on blob storage;
• extracting a primary key of each row from the rows returned from the secondary index scan operation;
• identifying a corresponding range of each extracted primary key in the blob storage;
• scanning each corresponding range of the blob storage to identify a set of rows that satisfy a set of predicates on an index column;
• and
• providing a set of rows as a result of the query.

A non-transitory computer-storage medium comprising instructions that, when executed by one or more processors of a machine, configure the machine to perform operations comprising:

• receiving a query, the query including at least one predicate for applying on a column of a table;
• performing a secondary index scan operation of a secondary index based on the query;
• adaptively determining, during execution of the secondary index scan operation, that a number of rows returned, from the secondary index scan operation, meets a threshold value, the threshold value comprising a cardinality of a particular set of values of a column of a table, and wherein the threshold value is determined by monitoring a count of rows returned during execution of the secondary index scan operation;
• in response to the number of rows meeting the threshold value, sending a signal to a primary index probe operation to initiate a blob storage scan using at least one range scan operation, wherein the signal triggers a runtime mode switch from index probe operations to range scan operations on blob storage;
• extracting a primary key of each row from the rows returned from the secondary index scan operation;
• identifying a corresponding range of each extracted primary key in the blob storage;
• scanning each corresponding range of the blob storage to identify a set of rows that satisfy a set of predicates on an index column;
• and
• providing a set of rows as a result of the query.