Abstract: Disclosed herein are systems and methods for efficiently querying external tables. In an embodiment, a database platform receives a query that is directed at least in part to external data in an external table stored on a data storage platform that is external to the database platform. The external table includes a plurality of partitions. The database platform identifies, from external-table metadata, a subset of the plurality of partitions of the external table as including data that potentially satisfies the query. The external-table metadata is stored by the database platform. The database platform identifies data that satisfies the query by scanning the identified subset of the partitions, and responds to the query at least in part with the identified data that satisfies the query.

Abstract: A method includes detecting, by at least one hardware processor, a change request for a table of a database, the table comprising a plurality of micro-partitions. A transaction associated with the change request is executed at a first timestamp. The transaction causes replacement of a first micro-partition of the plurality of micro-partitions with a second micro-partition. A change tracking column is generated in the second micro-partition. The change tracking column comprises metadata for the transaction. A delta for the table between the first timestamp and a second timestamp is generated using the metadata in the change tracking column. The delta indicates changes made to one or more rows of the table between the first time stamp and the second timestamp.

Abstract: A system includes one or more processors and data storage containing instructions executable by the one or more processors to perform operations. The operations include detecting a first executed transaction causing a first modification to table data stored in a table. The table data is associated with a corresponding metadata file with metadata information of the table. A new metadata file is generated responsive to the first executed transaction. The new metadata file includes the metadata information and additional metadata associated with the first modification. A second executed transaction causing a second modification to the table data is detected. The table data is updated with a change tracking column. The change tracking column includes lineage of executed transactions on the table data. The lineage indicates at least the first transaction and the second transaction.

Abstract: A method includes partitioning a database table into a first plurality of partitions. A plurality of changes are executed on the database table in response to a transaction. The changes occur at a corresponding plurality of timestamps and result in a second plurality of partitions. The database table is updated to include a log with the plurality of changes. For each change of the plurality of changes, the log includes and an identification of a portion of the database table the change is applied to. A selection of a first timestamp and a second timestamp of the plurality of timestamps is detected. A delta is generated in response to the selection. The delta indicates a total change occurring to the database table between a first change of the plurality of changes corresponding to the first timestamp and a second change of the plurality of changes corresponding to the second timestamp.

Abstract: In an embodiment, a database platform receives a query that is directed at least in part to external data in an external table stored on a data storage platform that is external to the database platform. The external table includes a plurality of partitions. The database platform identifies, from external-table metadata, a subset of the plurality of partitions of the external table as including data that potentially satisfies the query. The external-table metadata is stored by the database platform. The database platform identifies data that satisfies the query by scanning the identified subset of the partitions, and responds to the query at least in part with the identified data that satisfies the query.

Abstract: A method for table data processing includes retrieving, by at least one hardware processor, first table data associated with a first table version from a plurality of partitions of a storage device. The method further includes detecting, by the at least one hardware processor, an executed transaction causing a modification to the first table data resulting in a second table data associated with a second table version. The second table data is modified to include partition metadata. The partition metadata includes table version information with a mapping of the first table version and the second table version to a plurality of transactions associated with generating the first table data and the second table data.

Abstract: Systems, methods, and devices for tracking a series of changes to database data are disclosed. A method includes executing a transaction to modify data in a micro-partition of a table of a database by generating a new micro-partition that embodies the transaction. The method includes associating transaction data with the new micro-partition, wherein the transaction data comprises a timestamp when the transaction was fully executed, and further includes associating modification data with the new micro-partition that comprises an indication of one or more rows of the table that were modified by the transaction. The method includes joining the transaction data with the modification data to generate joined data and querying the joined data to determine a listing of intermediate modifications made to the table between a first timestamp and a second timestamp.

Abstract: Disclosed herein are embodiments of systems and methods for partition-based scanning of external tables for query processing. In an example embodiment, a database platform receives a query that includes one or more predicates, where the query is directed at least to data in an external table that is stored in an external storage platform that is external to the database platform. The database platform identifies, based on metadata that summarizes the data in the external table, one or more partitions of the external table that potentially include data that satisfies the one or more predicates. The database platform also identifies, from the one or more identified partitions, data that satisfies the one or more predicates. The database platform sends a response to the query to the client, the response comprising the data satisfying the one or more predicates.

Abstract: A method for table data processing includes retrieving, by at least one hardware processor, first table data associated with a first table version from a plurality of partitions of a storage device. The method further includes detecting, by the at least one hardware processor, an executed transaction causing a modification to the first table data resulting in a second table data associated with a second table version. The second table data is modified to include partition metadata. The partition metadata includes table version information with a mapping of the first table version and the second table version to a plurality of transactions associated with generating the first table data and the second table data.

Abstract: The subject technology executes a change on an existing micro-partition of a table of a database, the executing of the change comprising generating a new micro-partition that embodies the change. The subject technology receives a request for a delta for the table between a first timestamp and a second timestamp. The subject technology queries at least one change tracking column to determine the delta between the first timestamp and the second timestamp, the delta including information indicating at least one database operation that was performed to at least one row of a set of rows of the table, without including information as to intermediate changes made to at least one row of the set of rows of the table between the first timestamp and the second timestamp, that facilitates a reduction in storage of historical versions of the set of rows of the table.

Abstract: Systems, methods, and devices for tracking a series of changes to database data are disclosed. A method includes executing a transaction to modify data in a micro-partition of a table of a database by generating a new micro-partition that embodies the transaction. The method includes associating transaction data with the new micro-partition, wherein the transaction data comprises a timestamp when the transaction was fully executed, and further includes associating modification data with the new micro-partition that comprises an indication of one or more rows of the table that were modified by the transaction. The method includes joining the transaction data with the modification data to generate joined data and querying the joined data to determine a listing of intermediate modifications made to the table between a first timestamp and a second timestamp.

Abstract: Systems, methods, and devices for generating a transactional change tracking summary for a database. A method includes executing a transaction on a table of a database, wherein the table includes a micro-partition and the transaction is executed on the micro-partition. The method includes, in response to the transaction being fully executed, generating a change tracking entry comprising an indication of one or modifications made to the table by the transaction. The method includes storing the change tracking entry in a change tracking stream, wherein the change tracking stream includes one or more sequential change tracking entries that each correspond to a different transaction that is fully executed on the table.

Abstract: Systems, methods, and devices for scheduling of data processing tasks are disclosed. A method includes performing a modification on a first set of immutable partitions storing database data to generate a second set of immutable partitions. The second set is associated with a modified version of the database data. A change tracking entry is entered in a stream of tracking entries based on committing the modification. The change tracking entry includes an indication of the modification on the first set of immutable partitions. A stream offset of the stream of tracking entries is advanced based on the entering of the change tracking entry in the stream of tracking entries. The stream offset indicates a timestamp associated with a latest committed modification to the database data. A data processing task is scheduled for execution on the modified version of the database data based on the advancing of the stream offset.

Abstract: Systems, methods, and devices for generating a materialized view over an external table. A method includes connecting a database platform to an external table such that the database platform has read access for the external table and does not have write access for the external table. The method includes generating, by the database platform, a materialized view over the external table. The method includes receiving a notification that a modification has been made to the external table, the modification comprising one or more of an addition of a file, a deletion of a file, or an update to a file in a source location for the external table. The method includes, in response to the external table being modified, refreshing the materialized view such that the materialized view comprises an accurate representation of the external table.

Abstract: Disclosed herein are systems and methods for efficiently querying external tables. In an embodiment, a database platform receives a query that is directed at least in part to external data in an external table stored on a data storage platform that is external to the database platform. The external table includes a plurality of partitions. The database platform identifies, from external-table metadata, a subset of the plurality of partitions of the external table as including data that potentially satisfies the query. The external-table metadata is stored by the database platform. The database platform identifies data that satisfies the query by scanning the identified subset of the partitions, and responds to the query at least in part with the identified data that satisfies the query.

Abstract: A system includes one or more processors and data storage containing instructions executable by the one or more processors to perform operations. The operations include detecting a first executed transaction causing a first modification to table data stored in a table. The table data is associated with a corresponding metadata file with metadata information of the table. A new metadata file is generated responsive to the first executed transaction. The new metadata file includes the metadata information and additional metadata associated with the first modification. A second executed transaction causing a second modification to the table data is detected. The table data is updated with a change tracking column. The change tracking column includes lineage of executed transactions on the table data. The lineage indicates at least the first transaction and the second transaction.

Abstract: Disclosed herein are embodiments of systems and methods for partition-based scanning of external tables for query processing. In an example embodiment, a database platform receives a query that includes one or more predicates, where the query is directed at least to data in an external table that is stored in an external storage platform that is external to the database platform. The database platform identifies, based on metadata that summarizes the data in the external table, one or more partitions of the external table that potentially include data that satisfies the one or more predicates. The database platform also identifies, from the one or more identified partitions, data that satisfies the one or more predicates. The database platform sends a response to the query to the client, the response comprising the data satisfying the one or more predicates.

Abstract: A method includes partitioning a database table into a first plurality of partitions. A plurality of changes are executed on the database table in response to a transaction. The changes occur at a corresponding plurality of timestamps and result in a second plurality of partitions. The database table is updated to include a log with the plurality of changes. For each change of the plurality of changes, the log includes and an identification of a portion of the database table the change is applied to. A selection of a first timestamp and a second timestamp of the plurality of timestamps is detected. A delta is generated in response to the selection. The delta indicates a total change occurring to the database table between a first change of the plurality of changes corresponding to the first timestamp and a second change of the plurality of changes corresponding to the second timestamp.

Abstract: A system includes one or more processors and data storage containing instructions executable by the one or more processors to perform operations. The operations include storing table data in a plurality of partitions of a storage device. Metadata is retrieved from a first partition of the plurality of partitions. The metadata includes a plurality of change tracking entries stored as a change tracking stream. A lineage of modifications made to the table data is determined using the plurality of change tracking entries. A report of one or more transactions performed on the table data is generated. The one or more transactions are included in the lineage of modifications.

Abstract: Disclosed herein are systems and methods for pruning external data. In an embodiment, a database platform receives a query directed at least in part to external data in an external table on an external data storage platform. The external table includes partitions that correspond to storage locations in a source directory of the external data storage platform. The storage locations contain files that contain the external data. The database platform identifies, from external-table metadata that is stored by the database platform and that maps the partitions of the external table to the storage locations in the source directory, a subset of the partitions as including data that potentially satisfies the query. The database platform identifies data that satisfies the query by scanning the identified subset of the partitions, and responds to the query at least in part with the identified data that satisfies the query.