Abstract: Some embodiments provide a method for migrating data from a first database to a second database. The data is susceptible to change at the first database before all of the data is migrated to the second database and is available for access through the second database. The method transfers segments of data incrementally from the first database to the second database and generates a first digital signature for each transferred segment. The method identifies a set of transferred segments that have been modified in the first database before the data is available for access through the second database by generating a second digital signature for each transferred segment in the set and comparing the second digital signature for the segments with the first digital signature for the segments. The method transfers the modified segments from the first database to the second database in order to replace the previously transferred segments.

Abstract: A method for providing database management system support to a source application configured to operate with a source database management system Is provided. The method comprises detecting database management system communications issued by the source application to the source database management system; and responsive to said database management systems communications, impersonating the source database management system to the source application.

Abstract: Some embodiments provide a method for quantifying the workload placed on a database by an application. The method identifies a first group of database queries that the application directed towards the database. The method produces a second group of queries by removing, from the first group of queries, queries that are duplicates based on the semantic structure of the queries. Based on a set of properties of the second group of queries, the method computes a complexity indicator that represents a complexity expression of the second group of queries.

Abstract: Some embodiments provide a method of emulating a presentation of at least one system object of a first database, based on multiple system objects of a second database. From a client, the method receives a first query for the first database requesting a presentation of the system object. From a metadata storage, the method identifies a second query for the second database that references the system objects of the second database, and generates the requested presentation of the system object. The method replies to the client with the generated presentation.

Abstract: A system for controlling access to a downstream database management system (DMS) is provided. The system comprises an interface to maintain client connections with a plurality of upstream clients; a pooling component to establish a dynamic pool, and to selectively route each client connection to a pool; within each pool maintaining a queue comprising client database requests associated with particular client connections; and selectively granting access to the client database requests within each queue to at least one downstream DMS.

Abstract: Some embodiments provide a method for migrating data from a first database to a second database. The method uses a data segmentation process to dynamically determine a set of segmentation criteria for a particular portion of the first database. The method uses the set of segmentation criteria to divide the particular portion of the first database into multiple data segments. The method incrementally transfers the multiple data segments from the first database to the second database.

Abstract: Some embodiments provide a method for quantifying complexity of database queries that reference database objects in a database. The method identifies a database query that includes a reference to a set of one or more database objects in the database. The method identifies a set of properties associated with a set of components of the identified query, and computes, from the identified set of properties, a complexity indicator that represents a complexity expression of the database query.

Abstract: For multiple queries written for a first database, some embodiments provide a method of processing the queries on a second database. From a client, the method receives individually each of the multiple queries written for the first database. The method performs an automated process to analyze properties of the second database to determine that the multiple queries can be replaced by a single query to the second database. Based on the determination, the method combines the multiple queries to generate a single query for the second database. The method forwards the generated single query to the second database for execution.

Abstract: Some embodiments provide a method for analyzing database queries performed on a database. The method receives log data associated with queries that were performed on the database, wherein the log data includes multiple sub-tables that each include a set of data entries. Based on the log data, the method assembles a set of queries that were performed on the database, where different queries in the set are assembled by combining different subsets of data entries from the sub-tables. The method performs a query interpretation operation on each query to quantify the impact of performing the assembled set of queries on the database.

Abstract: Some embodiments provide a method for migrating a set of data objects from a first database of a first database type to a second database of a second database type. The method retrieves a particular set of data from the first database and performs an automated process to analyze the particular set of data in order to select the second database type from multiple other database types. The method presents on a display the selected second database type and a user interface control for migrating the set of data objects stored in the first database to the second database of the second database type. In response to a selection of the user interface control, the method provisions the second database and transfers the set of data objects from the first database to the second database.

Abstract: For a query written for a first database, some embodiments provide a method of processing the query on a second database. From a client, the method receives the query written for the first database. The method performs an automated process to analyze properties of the second database to determine that the received query should be replaced by multiple queries to the second database. Based on the determination, the method generates multiple queries for the second database. The method individually forwards each generated query to the second database for execution.

Abstract: Some embodiments provide an automated method for processing a query. The method receives a query from a client, where the query references an object in a source database, the object having two sets of properties. The method generates a full set of properties by retrieving one set of properties from the target database and retrieving the other set of properties from a metadata storage. Based on the full, combined set of properties, the method generates a new query for execution on the target database.

Abstract: Some embodiments provide a method for migrating data from a first database to a second database. The data is susceptible to change at the first database before all of the data is migrated to the second database and is available for access through the second database. The method transfers segments of data incrementally from the first database to the second database and generates a first digital signature for each transferred segment. The method identifies a set of transferred segments that have been modified in the first database before the data is available for access through the second database by generating a second digital signature for each transferred segment in the set and comparing the second digital signature for the segments with the first digital signature for the segments. The method transfers the modified segments from the first database to the second database in order to replace the previously transferred segments.

Abstract: Some embodiments provide a method for migrating a set of data objects from a first database of a first database type to a second database of a second database type. The method receives a selection of the second database type and receives a selection of a user interface control for initiating the database migration from the first database of the first database type to the second database of the selected second database type. The method provisions the second database and transfers the set of data objects from the first database to the second database.

Abstract: Some embodiments provide a method for expressing viability of a first database as a candidate for replacing a second database. The method identifies a first group of database queries that a group of applications directed towards the second database. The method produces a second group of queries by removing, from the first group, queries that are duplicates. Based on a set of complexity values associated with a set of components of the second group of queries, the method generates a complexity indicator representing a level of difficulty for rewriting the second group of queries for the second database.

Abstract: For an updateable view that is defined for a first database, some embodiments provide an automated method for processing an update to data tuples in a second database, the update specified by reference to the updateable view. The method receives a first query from a client for modifying a particular data tuple presented in the updateable view. From a metadata storage, the method retrieves a definition of the updateable view, where the definition includes a reference to a first set of one or more objects associated with the particular data tuple in the first database. Based on the retrieved definition, the method generates a second query referencing a second set of one or more objects associated with the particular data tuple in the second database. The method executes the generated second query on the second database, to modify the particular data tuple in the second database.

Abstract: Some embodiments provide a method for analyzing database queries performed on a database. The method receives a log that includes a set of database queries that were performed on the database. The method identifies, from the log, two or more subsets of queries that are each associated with a different connection session between the database and a set of client applications, where each subset is associated with a set of temporary session objects that are not associated with queries in the other subsets of queries. The method performs a separate query interpretation process on each subset of queries to quantify the impact of performing the queries on the database during the connection sessions, where the query interpretation processes are performed separately in order to avoid errors associated with the temporary objects.

Abstract: A method for providing database management system support to a source application configured to operate with a source database management system Is provided. The method comprises detecting database management system communications issued by the source application to the source database management system; and responsive to said database management systems communications, impersonating the source database management system to the source application.

Abstract: A method for providing interoperability between a plurality of database management system. The method comprises a server communicably connected to a plugin-application; receiving, from the source application, a connection request; intercepting communications issued by the source application to a source database management system; and responsive to said intercepted communications, impersonating the source database management system as a target database management system.

Abstract: A system for controlling access to a downstream database management system (DMS) is provided. The system comprises an interface to maintain client connections with a plurality of upstream clients; a pooling component to establish a dynamic pool, and to selectively route each client connection to a pool; within each pool maintaining a queue comprising client database requests associated with particular client connections; and selectively granting access to the client database requests within each queue to at least one downstream DMS.