Abstract: An example operation may include one or more of hosting a first virtual node in a blockchain-as-a-service (Baas) provider, hosting a second virtual node in the Baas provider, and controlling transmission of information between the first virtual node and the second virtual node along an internal signal path of the Baas provider, wherein the information corresponds to a block in a blockchain that includes an entry for the first and second virtual nodes.

Abstract: Sorting and storing a dataset, the dataset comprising at least one attribute. The method includes defining a set of data blocks and assigning to each data block a predefined maximum number of entries or a predefined maximum amount of storage, dividing the dataset into a sequence of multiple sub-datasets each having one value or a range of values of the attribute, wherein each pair of successive sub-datasets of the sequence are non-overlapping or overlapping at their respective extremum value of the attribute, for each sub-dataset of the multiple sub-datasets: in case the sub-dataset fully or partially fits into a data block of the defined data blocks storing the sub-dataset into at least the data block, the sub-dataset that partially fits into the data block comprising a number of entries that is smaller than a predefined maximum threshold.

Abstract: Dispatching a database request. A database request is received. Latency times are determined for databases managed by the DBMS, the latency times being estimates of the times to complete replications from the other databases of all unreplicated data changes in the other databases. For each database, a capture velocity and an apply are determined, which are a number of data changes applied to the database that can be identified or applied in a predefined time interval. For each database, an estimated time to complete the database request is determined. The database request is dispatched to the database having an estimated minimum time of execution of the database request, wherein the time of execution is function of the estimated time for the database to complete the database request, the latency time of the database, and the capture and apply velocities of the database.

Abstract: A computer receives a database request to be executed on a source database or a target database. The source database is configured to efficiently process database queries of a first query type, the target database is configured to efficiently process database queries of a second query type, data changes in the source database are asynchronously replicated to the target database, and all changed data in the source database impacting a result of the database request are replicated to the target database before executing the database request. The computer determines a latency time to asynchronously complete a replication of unreplicated data changes and determines a velocity of replication. The computer predicts, using the latency time and velocity of replication, which of the databases will complete an execution of the database request first and dispatches the database request to the database predicted to complete the execution of the database request first.

Abstract: Aspects of the invention include processing queries in a database system having a first database engine and a second database engine. A first instance of a first table is stored in the first database engine in plaintext. At one predefined column of the first table is encrypted, resulting in a set of encrypted columns, using a cascade encryption scheme that includes a set of ordered encryption methods. A subset of the set of columns is stored in a second instance of the first table in the second database engine. An encryption method of the cascade encryption scheme that allows a query operation of a received query on data encrypted with the identified encryption method is identified. The identified encryption method is used to rewrite the query, and the rewritten query is executed using the second instance of the first table.

Abstract: Aspects of the invention include processing queries in a database system having a first database engine and a second database engine. A first instance of a first table is stored in the first database engine in plaintext. At one predefined column of the first table is encrypted, resulting in a set of encrypted columns, using a cascade encryption scheme that includes a set of ordered encryption methods. A subset of the set of columns is stored in a second instance of the first table in the second database engine. An encryption method of the cascade encryption scheme that allows a query operation of a received query on data encrypted with the identified encryption method is identified. The identified encryption method is used to rewrite the query, and the rewritten query is executed using the second instance of the first table.

Abstract: The present disclosure relates to a method for processing data in a database engine. The method includes storing a first instance of a first table in the database engine in plaintext. Encryption information about encryption methods and encryption keys of at least one predefined column of the first table may be maintained. In response to data changes in the column, first log entries for the data changes may be written in plaintext. The data changes may be encrypted by an encryption component using the encryption information. This results in encrypted data changes. Second log entries for the encrypted data changes may be written and applied to a second instance of the first table. The second instance of the first table is stored at a further database engine.

Abstract: The present disclosure relates to a method for processing data in a database engine. The method includes storing a first instance of a first table in the database engine in plaintext. Encryption information about encryption methods and encryption keys of at least one predefined column of the first table may be maintained. In response to data changes in the column, first log entries for the data changes may be written in plaintext. The data changes may be encrypted by an encryption component using the encryption information. This results in encrypted data changes. Second log entries for the encrypted data changes may be written and applied to a second instance of the first table. The second instance of the first table is stored at a further database engine.

Abstract: The present disclosure relates to a method for processing queries in a database system having a first database engine and a second database engine. The method includes: storing a first instance of a first table in the first database engine in plaintext; encrypting at least one predefined column of the first table, resulting in a second instance of the first table containing at least part of the data of the first table in encrypted format. The second instance of the first table in the second database engine is stored in the second database engine. It may be determined whether to execute a received query in the first database engine on the first table or in the second database engine on the second instance of the first table, where the determination involves a comparison of the query with encryption information.

Abstract: The present disclosure relates to a method for processing queries in a database system having a first database engine and a second database engine. The method includes: encrypting at least one predefined column of a first instance of a first table, resulting in a second instance of the first table containing at least part of the data of the first table in encrypted format. It may be determined whether to execute a received query in the first database engine on the first instance of the first table or in the second database engine on the second instance of the first table, where the determination involves a comparison of the query with encryption information.

Abstract: Sorting and storing a dataset, the dataset comprising at least one attribute. The method includes defining a set of data blocks and assigning to each data block a predefined maximum number of entries or a predefined maximum amount of storage, dividing the dataset into a sequence of multiple sub-datasets each having one value or a range of values of the attribute, wherein each pair of successive sub-datasets of the sequence are non-overlapping or overlapping at their respective extremum value of the attribute, for each sub-dataset of the multiple sub-datasets: in case the sub-dataset fully or partially fits into a data block of the defined data blocks storing the sub-dataset into at least the data block, the sub-dataset that partially fits into the data block comprising a number of entries that is smaller than a predefined maximum threshold.

Abstract: A method, system and computer program product for providing consolidated access to data of a plurality of source databases. Tables of each of the source databases are replicated to a shared accelerator. The source DBMSs are configured to dispatch queries to the accelerator for accelerating query execution. The accelerator is configured such that the replicated tables can only be accessed by the source DBMS having provided said tables for executing a dispatched query. A user can select one of the source DBMSs to act as a consolidated DBMS—C-DBMS. The C-DBMS provides the consolidated access. The user is enabled to select tables managed by another one of the DBMSs. In response to receiving the selection of the tables, the accelerator is re-configuring such that the C-DBMS is granted access also to the copies of the selected tables in the accelerator.

Abstract: The present disclosure relates to a method for processing queries in a database system having a first database engine and a second database engine. The method includes: storing a first instance of a first table in the first database engine in plaintext; encrypting at least one predefined column of the first table, resulting in a second instance of the first table containing at least part of the data of the first table in encrypted format. The second instance of the first table in the second database engine is stored in the second database engine. It may be determined whether to execute a received query in the first database engine on the first table or in the second database engine on the second instance of the first table, where the determination involves a comparison of the query with encryption information.

Abstract: A method, system and computer program product for providing consolidated access to data of a plurality of source databases. Tables of each of the source databases are replicated to a shared accelerator. The source DBMSs are configured to dispatch queries to the accelerator for accelerating query execution. The accelerator is configured such that the replicated tables can only be accessed by the source DBMS having provided said tables for executing a dispatched query. A user can select one of the source DBMSs to act as a consolidated DBMS—C-DBMS. The C-DBMS provides the consolidated access. The user is enabled to select tables managed by another one of the DBMSs. In response to receiving the selection of the tables, the accelerator is re-configuring such that the C-DBMS is granted access also to the copies of the selected tables in the accelerator.

Abstract: A method, system and computer program product for providing consolidated access to data of a plurality of source databases. Tables of each of the source databases are replicated to a shared accelerator. The source DBMSs are configured to dispatch queries to the accelerator for accelerating query execution. The accelerator is configured such that the replicated tables can only be accessed by the source DBMS having provided said tables for executing a dispatched query. A user can select one of the source DBMSs to act as a consolidated DBMS-C-DBMS. The C-DBMS provides the consolidated access. The user is enabled to select tables managed by another one of the DBMSs. In response to receiving the selection of the tables, the accelerator is re-configuring such that the C-DBMS is granted access also to the copies of the selected tables in the accelerator.

Abstract: Methods and apparatus, including computer program products, for maintaining a set of indexes in a database management system (DBMS) having at least one table. A current, stale or deferred status is defined for at least a part of the indexes, resulting in at least a part of a set of current, stale, or deferred indexes in the DBMS. Current indexes are maintained by refreshing a current index synchronously with a table change relating to the current index. Stale indexes are maintained by refreshing a stale index continuously and asynchronously to table modifications of tables relating to the stale index based on log information relating to the modifications. Deferred indexes are maintained by building a deferred index in response to a query to a table relating to the deferred index, thereby bringing the deferred index in accordance with the current query time status to the table relating to the deferred index.

Abstract: A method, system and computer program product for providing consolidated access to data of a plurality of source databases. Tables of each of the source databases are replicated to a shared accelerator. The source DBMSs are configured to dispatch queries to the accelerator for accelerating query execution. The accelerator is configured such that the replicated tables can only be accessed by the source DBMS having provided said tables for executing a dispatched query. A user can select one of the source DBMSs to act as a consolidated DBMS—C-DBMS. The C-DBMS provides the consolidated access. The user is enabled to select tables managed by another one of the DBMSs. In response to receiving the selection of the tables, the accelerator is re-configuring such that the C-DBMS is granted access also to the copies of the selected tables in the accelerator.

Abstract: The present disclosure relates to a method for processing queries in a database system having a first database engine and a second database engine. The method includes: storing a first instance of a first table in the first database engine in plaintext; encrypting at least one predefined column of the first table, resulting in a second instance of the first table containing at least part of the data of the first table in encrypted format. The second instance of the first table in the second database engine is stored in the second database engine. It may be determined whether to execute a received query in the first database engine on the first table or in the second database engine on the second instance of the first table, where the determination involves a comparison of the query with encryption information.

Abstract: The present disclosure relates to a method for processing data in a database engine. The method includes storing a first instance of a first table in the database engine in plaintext. Encryption information about encryption methods and encryption keys of at least one predefined column of the first table may be maintained. In response to data changes in the column, first log entries for the data changes may be written in plaintext. The data changes may be encrypted by an encryption component using the encryption information. This results in encrypted data changes. Second log entries for the encrypted data changes may be written and applied to a second instance of the first table. The second instance of the first table is stored at a further database engine.

Abstract: Aspects of the invention include processing queries in a database system having a first database engine and a second database engine. A first instance of a first table is stored in the first database engine in plaintext. At one predefined column of the first table is encrypted, resulting in a set of encrypted columns, using a cascade encryption scheme that includes a set of ordered encryption methods. A subset of the set of columns is stored in a second instance of the first table in the second database engine. An encryption method of the cascade encryption scheme that allows a query operation of a received query on data encrypted with the identified encryption method is identified. The identified encryption method is used to rewrite the query, and the rewritten query is executed using the second instance of the first table.