Abstract: The present application relates to managing memory of a KLL sketch for a streaming set. A computer system allocates an initial amount of memory from a computer memory to a buffer of a KLL sketch data structure based on a sparse sketch size independent of a data type of the streaming set. The system allocates an incremental amount of memory greater than or equal to the initial amount of memory from the computer memory to the buffer in response to a size of the streaming set exceeding a supported stream size of the KLL sketch data structure. The system determines a number of levels of the KLL sketch data structure based on a total allocated amount of memory and a size of the data type of the streaming set. The system adds new elements from the streaming set to the KLL sketch data structure based on the number of levels.

Abstract: The present application relates to managing memory of a KLL sketch for a streaming set. A computer system allocates an initial amount of memory from a computer memory to a buffer of a KLL sketch data structure based on a sparse sketch size independent of a data type of the streaming set. The system allocates an incremental amount of memory greater than or equal to the initial amount of memory from the computer memory to the buffer in response to a size of the streaming set exceeding a supported stream size of the KLL sketch data structure. The system determines a number of levels of the KLL sketch data structure based on a total allocated amount of memory and a size of the data type of the streaming set. The system adds new elements from the streaming set to the KLL sketch data structure based on the number of levels.

Abstract: In one embodiment, a computer-implemented method of a distributed database system included the step of providing a query processor to receive a query request and to chart out a query execution plan based on the query request. The method includes the step of providing a data generator to generate a digest list based on the query request, wherein the list of digests comprises each stream or filter applied in servicing the query request. The method includes the step of providing a query engine to obtain a digest list from a multiple-data source as a result of the query request and to filter the digest list. The method includes the step of providing a query worker to obtain the query request and process the query request based on a type of the query request. The method includes the step of providing one or more query worker threads to perform an asynchronous I/O operation for the query request.

Abstract: In one exemplary embodiment, a method includes the step of executing, with at least one processor, a main database node server in a source-database node of a source-database cluster. The main database node server manages database server operations. The main database node server communicates a source-database cluster state and a specified server operation metadata to a data-shipping daemon. The specified server operation metadata, includes an information about server operation occurring on the source-database node. Another step includes executing a data-shipping daemon in the source-database node. The data-shipping daemon receives the specified server operation metadata and stores the specified server operation metadata in a digest log. The data log includes a file of the specified server operation metadata. The data-shipping daemon reads the digest log and communicate data referred to in the specified server operation metadata in the digest log to a destination database node in a destination database cluster.

Abstract: In one embodiment, a computer-implemented method of a distributed database system included the step of providing a query processor to receive a query request and to chart out a query execution plan based on the query request The method includes the step of providing a data generator to generate a digest list based on the query request, wherein the list of digests comprises each stream or filter applied in servicing the query request. The method includes the step of providing a query engine to obtain a digest list from a multiple-data source as a result of the query request and to filter the digest list. The method includes the step of providing a query worker to obtain the query request and process the query request based on a type of the query request. The method includes the step of providing one or more query worker threads to perform an asynchronous I/O operation for the query request.

Abstract: In one exemplary embodiment, a method includes the step of executing, with at least one processor, a main database node server in a source-database node of a source-database cluster. The main database node server manages database server operations. The main database node server communicates a source-database cluster state and a specified server operation metadata to a data-shipping daemon. The specified server operation metadata, includes an information about server operation occurring on the source-database node. Another step includes executing a data-shipping daemon in the source-database node. The data-shipping daemon receives the specified server operation metadata and stores the specified server operation metadata in a digest log. The data log includes a file of the specified server operation metadata. The data-shipping daemon reads the digest log and communicate data referred to in the specified server operation metadata in the digest log to a destination database node in a destination database cluster.