Abstract: The subject technology receives first metadata corresponding to a set of micro-partitions. The subject technology stores a first data structure and a second data structure in storage as a first file and a second file, first data structure including the first metadata and a second data structure including second metadata, the first metadata corresponding to a set of micro-partitions, the second metadata for a grouping of the first metadata, the second data structure including information associating the second metadata to the first metadata. The subject technology stores third metadata for a table, the third metadata comprising information about data stored in a micro-partition of the table.

Abstract: The subject technology caches, in connection with processing a first query, one or more table-metadata files in at least one of a current version set of one or more table-metadata files and a new version set of one or more table-metadata files, the new version set of one or more table-metadata files comprising table metadata for a new version of a database table. The subject technology receives a subsequent query directed to the database table. The subject technology downloads, in connection with processing the subsequent query, at least one uncached table-metadata file in a scan set of table-metadata files for the subsequent query. The subject technology processes the subsequent query using the at least one uncached table-metadata file.

Abstract: The subject technology generates and stores a new version set of one or more table-metadata files, the new version set of one or more table-metadata files comprising table metadata for a new version of a database table. The subject technology determines that a plurality of table-metadata files are not included in a cache. The subject technology downloads, in parallel, the plurality of table-metadata files from immutable storage. The subject technology stores, in the cache, the plurality of table-metadata files. The subject technology reads, among the plurality of table-metadata files, a first table-metadata file before a second table-metadata file has been fully downloaded, the plurality of table-metadata files comprising at least the first table-metadata file and the second table-metadata file.

Abstract: The subject technology receives first metadata corresponding to a set of micro-partitions. The subject technology stores a first data structure and a second data structure in storage as a first file and a second file, first data structure including the first metadata and a second data structure including second metadata, the first metadata corresponding to a set of micro-partitions, the second metadata for a grouping of the first metadata, the second data structure including information associating the second metadata to the first metadata. The subject technology stores third metadata for a table, the third metadata comprising: cumulative table metadata comprising global information about a plurality of micro-partitions of the table, the cumulative table metadata being stored in a metadata micro-partition associated with the table.

Abstract: The subject technology generates a first data structure including first metadata and a second data structure including second metadata, the first metadata corresponding to a set of micro-partitions, the second metadata for a grouping of the first metadata, the second data structure including information associating the second metadata to the first metadata. The subject technology stores the first data structure and the second data structure in storage as a first file and a second file. The subject technology stores third metadata for a table, the third metadata comprising: cumulative table metadata comprising global information about a plurality of micro-partitions of the table, the cumulative table metadata being stored in a metadata micro-partition associated with the table.

Abstract: The subject technology receives first metadata corresponding to a set of micro-partitions. The subject technology generates second metadata for a grouping of the first metadata. The subject technology generates a first data structure including the first metadata and a second data structure including the second metadata, the second data structure including information associating the second metadata to the first metadata. The subject technology stores the first data structure and the second data structure in persistent storage as a first file and a second file. The subject technology receives a query on a table. Further, the subject technology analyzes the query against cumulative table metadata to determine whether data stored in the table matches the query.

Abstract: Aspects of the technology described herein detect experts in social networks. Experts may be identified within social networks using social network data. A collection of topics may be compiled based on search engine behavioral data. A combination of the social network data and search engine behavioral data is utilized to score each topic within potential topics for a user. When a topic score is over a predetermined threshold, a user may be classified as an expert for that topic. Expert search interfaces may be generated for use in browsing or searching for experts within a topic.

Abstract: The subject technology stores database data in a table, the table comprising a plurality of micro-partitions each having rows and columns. The subject technology stores metadata for the table in a data structure, the metadata comprising a first level of the data structure comprising a column expression property comprising information about data stored in a column of a micro-partition of the table, a micro-partition expression property comprising information about data stored in the micro-partition of the table, and a second level of the data structure comprising a grouping expression property comprising information about data stored in the micro-partition and one or more additional micro-partitions of the table.

Abstract: A method for sharing data in a multi-tenant database includes generating a share object in a first account comprising a share role. The method includes associating one or more access rights with the share role, wherein the one or more access rights indicate which objects in the first account are accessible based on the share object. The method includes granting, to a second account, cross-account access rights to the share role or share object in the first account. The method includes receiving a request from the second account to access data or services of the first account. The method further includes providing a response to the second account based on the data or services of the first account.

Abstract: A method for sharing data in a multi-tenant database includes granting, by one or more processors, a second role object in a target account access rights to an alias object, wherein the alias object references an object at a top of an object hierarchy. The method also includes granting the second role object in the target account access rights to a first role object included in a share object in a sharer account, wherein the share object includes a first role object having a set of grants to one or more resources of the sharer account, and wherein the target account accesses the one or more resources using the set of grants of the share object and using the alias object without copying the one or more resources.

Abstract: A method for sharing data in a multi-tenant database includes granting, by one or more processors, a second role object in a target account access rights to an alias object, wherein the alias object references an object at a top of an object hierarchy. The method also includes granting the second role object in the target account access rights to a first role object included in a share object in a sharer account, wherein the share object includes a first role object having a set of grants to one or more resources of the sharer account, and wherein the target account accesses the one or more resources using the set of grants of the share object and using the alias object without copying the one or more resources.

Abstract: A method for sharing data in a multi-tenant database includes receiving, by a target account of a multiple tenant database, access rights of a share object in a first account of the multiple tenant database, wherein the share object having access rights to a database object of the first account and wherein access to the database object of the first account by the target account is based on the access rights of the share object. The method also includes receiving, by one or more processors of the target account, access rights to an alias object, wherein the alias object references the database object of the first account.

Abstract: The subject technology receives first metadata corresponding to a set of micro-partitions. The subject technology generates second metadata for a grouping of the first metadata. The subject technology generates a first data structure including the first metadata and a second data structure including the second metadata, the second data structure including information associating the second metadata to the first metadata. Further, the subject technology stores the first data structure and the second data structure in persistent storage as a first file and a second file.

Abstract: A networked device communication system can configure network devices (e.g., a primary and secondary database) to send and receive sequences of messages, such as replicated data, using one or more keypairs and wrapping keys. The sequences of messages can include an initial set of messages that are encrypted by a wrapping key, and further include another set of messages that are encrypted by a replaced staggered key. The sequence of messages can be configured to be decrypted without exporting keys of hardware security modules.

Abstract: A networked device communication system can configure network devices (e.g., a primary and secondary database) to send and receive sequences of messages, such as replicated data, using one or more keypairs and wrapping keys. The sequences of messages can include an initial set of messages that are encrypted by a wrapping key, and further include another set of messages that are encrypted by a replaced staggered key. The sequence of messages can be configured to be decrypted without exporting keys of hardware security modules.

Abstract: A method for a database system includes storing table data for a database, the table data including information in rows and columns of one or more database tables. The method includes storing metadata on immutable storage, the metadata including information about the table data for the database. In one embodiment, mutable metadata may be periodically consolidated in the background to create new versions of metadata files and which allows for deletions of old metadata files and old data files.

Abstract: Systems, methods, and devices for implementing secure views for zero-copy data sharing in a multi-tenant database system are disclosed. A method includes generating a share object in a first account comprising a share role. The method includes associating view privileges for the share object such that an underlying detail of the share object comprises a secure view definition. The method includes granting, to a second account, cross-account access rights to the share role or share object in the first account. The method includes receiving a request from the second account to access data or services of the first account and providing a response to the second account based on the data or services of the first account. The method is such that the underlying detail of the share object that comprises the secure view definition is hidden from the second account and visible to the first account.

Abstract: The subject technology stores table metadata for a current version of a table in a current-version set of one or more table-metadata files. The subject technology detects a modification to the current version of the table, the modification resulting in a new version of the table, the new version of the table being stored in a new-version set of one or more table-data files, the new-version set of one or more table-data files being different than a current-version set of one or more table-data files.

Abstract: A method for sharing data in a multi-tenant database includes generating a share object in a first account comprising a share role. The method includes associating one or more access rights with the share role, wherein the one or more access rights indicate which objects in the first account are accessible based on the share object. The method includes granting, to a second account, cross-account access rights to the share role or share object in the first account. The method includes receiving a request from the second account to access data or services of the first account. The method further includes providing a response to the second account based on the data or services of the first account.

Abstract: Systems, methods, and devices for multiple level metadata organization in database systems. A system includes a plurality of shared storage devices collectively storing database data across a plurality of tables that each comprise one or more micro-partitions including immutable storage devices. The system includes a resource manager configured to manage the storage of database data stored in a table across one or more of the plurality of shared storage devices. The resource manager is configured to manage the storage of metadata for the table. The metadata includes a column expression property with information about data stored in a column, a micro-partition expression property with information about data stored in a micro-partition, a grouping expression property with information about data stored in two or more micro-partitions, and cumulative table metadata with global information about all micro-partitions of the table.