Abstract: A metadata catalog may store metadata about data sources. The metadata may define table, column, partition and/or data formats, as well as title information, textual descriptions, modification information, data schemas and access information, such as location and connection information. A metadata catalog service may provide a shared, persistent, central repository for the metadata. The metadata of the catalog may be published via multiple access mechanisms and programmatically obtained and processed by other programs via the metadata catalog service. Metadata consumers may utilize the metadata catalog service to perform various metadata tasks, such as metadata retrieval, creation, addition, modification and/or deletion. The metadata catalog service may be directly integrated into existing data analytic tools as a persistent and durable metadata store allowing users to utilize the broad set of data processing tools.

Abstract: A journaled database system may comprise data nodes that maintain a collection of data and provide read access to the data to a client in accordance with a read schema and write access to the client in accordance with a write schema. A change to the schemas may be proposed. A materialization schema may be identified based on correlated determinations that both of the read schema and the write schema are satisfiable based on the materialization schema. The proposed changes may be accepted when the read schema and write schema are simultaneously satisfiable.

Abstract: A journaled database system may comprise data nodes that collectively maintain a collection of data and provide clients with read and write access to the collection. Correlated classification functions may be associated with read and write operations, such that items affected by a write operation are classified similarly to items accessed during a read operation. Read and write signatures may be formed based on the classification. Conflicts may be detected by comparing the read and write signatures for equivalent or overlapping classifications.

Abstract: A metadata catalog may store metadata about data sources. The metadata may define table, column, partition and/or data formats, as well as title information, textual descriptions, modification information, data schemas and access information, such as location and connection information. A metadata catalog service may provide a shared, persistent, central repository for the metadata. The metadata of the catalog may be published via multiple access mechanisms and programmatically obtained and processed by other programs via the metadata catalog service. Metadata consumers may utilize the metadata catalog service to perform various metadata tasks, such as metadata retrieval, creation, addition, modification and/or deletion. The metadata catalog service may be directly integrated into existing data analytic tools as a persistent and durable metadata store allowing users to utilize the broad set of data processing tools.

Abstract: A metadata catalog may store metadata about data sources. The metadata may define table, column, partition and/or data formats, as well as title information, textual descriptions, modification information, data schemas and access information, such as location and connection information. A metadata catalog service may provide a shared, persistent, central repository for the metadata. The metadata of the catalog may be published via multiple access mechanisms and programmatically obtained and processed by other programs via the metadata catalog service. Metadata consumers may utilize the metadata catalog service to perform various metadata tasks, such as metadata retrieval, creation, addition, modification and/or deletion. The metadata catalog service may be directly integrated into existing data analytic tools as a persistent and durable metadata store allowing users to utilize the broad set of data processing tools.

Abstract: A client-side component of a journal-based multi-data-store database identifies an application schema corresponding to a first application whose data is stored at the database. The application schema includes a writes section indicating a data object to which writes are to be issued from the first application. A journal schema defining one or more data objects for which a concurrency-control protocol is implemented by a journal manager of the database is obtained. Before a transaction request of the application is submitted to the journal manager, the client-side component verifies that the application schema is compatible with the journal schema.

Abstract: A journaled database system may comprise data nodes that maintain a collection of data structured in accordance with a schema. A change to the schema may be applied by a journal module while a journal consumer continues to operate using a prior version of the schema. A buffer may be formed and have stored therein records describing state change instructions according to the prior view of the schema. An index of correspondence between the records in the buffer and in the source journal may be maintained.

Abstract: A journaled database system may comprise data nodes that maintain a collection of data structured in accordance with a schema. A change to the schema may be applied by a journal module while a journal consumer continues to operate using a prior version of the schema. A buffer may be formed and have stored therein records describing state change instructions according to the prior view of the schema. An index of correspondence between the records in the buffer and in the source journal may be maintained.